PDA

View Full Version : Largest piston engine in the world---



brian Rupnow
06-16-2008, 08:12 PM
Having recently finished my first steam engine (One of Elmers simple wobblers), and being a veteran insomniac, I was laying in bed the other night wondering just how small the worlds smallest piston engine is, and how large the largest one. I never messed around with model airoplanes, so really the smallest piston engine I have ever seen is the 3/8" diameter engine that I just built. I have seen pictures of really large engines in trans Atlantic ships, and I am curious ---would the largest piston engine be something current, or would it have been built at the time of the industrial revolution. I don't care if it was steam, gasoline, or diesel---long as it was a piston engine.

dp
06-16-2008, 08:22 PM
I don't care if it was steam, gasoline, or diesel---long as it was a piston engine.

It seems to me I recall the largest piston engine is in Europe at a retired powerplant, and that it still runs. It was talked about here recently.

JohnWFoster
06-16-2008, 09:16 PM
Google B&W (I believe Bergmeister and Wane , but not sure of the spelling) They make incredibly large marine engines.

deltaenterprizes
06-16-2008, 09:21 PM
COX made a .010 Baby Bee in the early 70s.

sconisbee
06-16-2008, 09:28 PM
perhaps a candidate for one of the biggest if not the biggest?

http://people.bath.ac.uk/ccsshb/12cyl/

Im not all that up on engines, though this one comes up in conversation from time to time as the Emma Mearsk has a 14 cylinder version.

A.K. Boomer
06-16-2008, 10:45 PM
Sconisbee I remember seeing that on here before, its amazing to say the least -- for one even though the thing is of great mass its still extremely precision looking in every aspect and detail, I cannot believe the shine on the main bearing bores.

I seem to recall my power mechanics teacher telling us of one of the large steam engines -- i believe it was used in a ship --- he had magic marker dots on the floor one day, he told us all to scoot our chairs into the inside parameter of all the dots, we did but it was a class full of at least 25 kids and maybe even 30 and it was cramped, Then he said that we all could fit on top of one of the pistons of such and such engine.

torker
06-16-2008, 11:27 PM
There is a huge ol' power plant out in Alberta that's been used to pump natural gas for decades.
A buddy of mine looked after it for years till they shut it down last year.
He sent me a pic of it once... had a big ol' fashion cell phone resting on the top of a head stud. The cell phone didn't begin to cover the width of the stud. The nut holding the head on was absolutely huge!!
He has a huge ol' con rod out of that motor. Uses it as an oversized gate post in his driveway.
Not the biggest but pretty damm big for out on the prairies.
I've always wondered how they moved that monster out there.
Russ

aostling
06-17-2008, 01:09 AM
The largest piston ever built was for an Ericsson engine. From http://en.wikipedia.org/wiki/Ericsson_cycle


The Ericsson Cycle Engine (The second of the two discussed here) was used to power a 2000 ton ship, The Caloric Ship Ericsson and the engine ran flawlessly for 73 hours. The combination engine produced about 300 horsepower. It had a combination of 4 dual-piston engines; the larger expansion piston/cylinder, at 4.267 meters or 14 feet in diameter, was perhaps the largest piston ever built.

That engine ran at a sedate 6.5 RPM.

gmatov
06-17-2008, 01:35 AM
Not the largest pistons, but the most powerful engine is posted somewhere here or at PM.

Mebbe 100 feet long (could be wrong) burns about a gallon per revolution, pushes the largest container ships.

Ladders welded to the walls of the bearing supports to get down into the crankcase.

CRANKSHAFT is something like 100 tons.

If I can find it, I will link.

Beautiful!

Cheers,

George

Evan
06-17-2008, 07:53 AM
http://people.bath.ac.uk/ccsshb/12cyl/

JCHannum
06-17-2008, 07:57 AM
While we cannot aspire to build a larger engine than the largest, someone might be able to build one smaller than the smallest.

At present that accomplishment appears to be held by George Luhrs;

http://craftsmanshipmuseum.com/Luhrs.htm

A.K. Boomer
06-17-2008, 08:32 AM
http://people.bath.ac.uk/ccsshb/12cyl/



Evan did you slip a cog? Again?:)

DICKEYBIRD
06-17-2008, 08:45 AM
COX made a .010 Baby Bee in the early 70s.Ahh, a subject I am familiar with.:) Actually the .010 was in the Cox "Tee Dee" series which began in 1961. Tee Dees (front rotary valve, glow ignition 2-strokes) were manufactured in .010, .020, .049, .051, .09 and .15 cu. in. sizes.

The Babe Bee's were all reed valve .049's. The "reedies" were made in (Pee Wee) .020, (Babe Bee) .049, (Killer Bee) .051, and (Queen Bee) .074 cu. in. sizes.

Cox engines were MASS produced (millions!) in a 24/7 temperature controlled factory in California with no CNC machines (lotsa screw machines though) to a very consistent & high quality level with extremely tight tolerances and were low priced to boot. We could use a few more Leroy Coxes in America today.

There is a fellow in Europe that makes extremely small diesel model engines that make the Tee Dee .010 look like a giant but I can't find a link to them at the moment.

Evan
06-17-2008, 08:55 AM
Evan did you slip a cog? Again?:)

That is the engine George referred to. What did you think?

A.K. Boomer
06-17-2008, 09:08 AM
I believe Sconsisbee already posted the identical link to it a few posts before yours, Just pickin on you:p

I think its amazing, those mains really get me, I bet those guys can see themselves in that finish...

Edit; Actually something does perplex me, Am I missing something? yes I am, dont you think an engine of that size spinning at just 102 RPM's would need a flywheel the size of cleveland?
I know its quite a few cylinders - I know the crank weighs in @ 300 tons (but keep in mind that its all in tight radius so does not account for "much" --- "much" in comparison to what you think would be needed), but the rest of the engine is 2,000 tons and much of that reciprocating parts that I also might add are firing off a diesel mix so the compression ratio must be adequate -- where's the freekin flywheel to that beast of burden?
maybe the 10 cylinder has to have a bigger one than the 14?

A.K. Boomer
06-17-2008, 09:31 AM
DB - why did cox make a .049 and a .051? I mean there almost identical -- was the .051 different design? It seems like allot to go through with re-tooling and such just to come up with .002 ci ------- ?

I had a couple of .049's as a kid, fun little engines.

Evan
06-17-2008, 10:36 AM
Actually something does perplex me, Am I missing something? yes I am, dont you think an engine of that size spinning at just 102 RPM's would need a flywheel the size of cleveland?

Mass increases as the cube of linear dimensions. The crankshaft is more than enough flywheel.

A.K. Boomer
06-17-2008, 11:03 AM
"Mass increases as the cube of linear dimensions."


Yes but Evan, cant that also be said for the immense pistons and rods and their effects? and what about power impulses that that things putting out?

I know you must be right - every time iv seen one of these pics of a large engine like this I dont recall ever seeing what I would call a proper proportioned flywheel. is it kinda like drop an ant and an elephant from a plane and see which one survives --- but again, the pistons and rods are equally intimidating just as much as the crank, guess it doesnt work that way...:confused:

Or does that engine shaft end up in an entirely different room dedicated just for the 3,750 ton 90 ft radius flywheel ;>}

barts
06-17-2008, 12:25 PM
"Mass increases as the cube of linear dimensions."
Yes but Evan, cant that also be said for the immense pistons and rods and their effects? and what about power impulses that that things putting out?


Well, on a 10 cylinder engine, there's a pretty good balance, so there isn't much need for a flywheel due to gravity. Remember, the compression forces only vary as the square of the lineal dimension.

Besides, on a 10 cylinder 2 stroke, you have a cylinder firing every 36 degrees of rotation - you really don't need a flywheel!

- Bart

A.K. Boomer
06-17-2008, 12:35 PM
Damn good point Bart, I forgot about the two stroke thing, and while thats occuring the compression strokes should be evenly matched to the power, (not matched in force but in timing --- which would still be a help as it would kind of equate to a mellower power impulse -- hey, you gotta pay the fiddler sometime right?) not too shabby fella.

Ausserdog
06-17-2008, 01:41 PM
Boomer,
It's been a long time, but I think the reason for the different displacements was to fit into different "classes". .049 was a "1/2 A", while .051 would fall into the "A" class.

That way you could build one model (usually Free Flight) and compete in two different classes.

sconisbee
06-17-2008, 01:54 PM
Sconisbee I remember seeing that on here before, its amazing to say the least -- for one even though the thing is of great mass its still extremely precision looking in every aspect and detail, I cannot believe the shine on the main bearing bores.

Its a thing of pure beauty, i mean i get to work on some fairly large engines in the marine world but nothing above 600hp yet, i would love to take a tour around the engineroom on the Emma Mærsk and someday i might just manage it as i know well a friend of a friend that works aboard and have been promised a tour however shes never in the right place at the right time when im around lol. ah well one day one day!

Edit: for a little more on the Wartsilla Engine, theres a clip of one here.
http://www.emma-maersk.com/videoclip/gallery/10/Wartsilla_Engine.htm

hitnmiss
06-17-2008, 03:05 PM
I had a Model Aviation magazine with a article "The amazing engines of _____" Can't remember the mans name. Lazlo?


Anyway he made engines down to .010" stroke by .010" bore if I remember correctly. They were CO2 engines. he had 5 of them in a Tylenol capsule and one was a radial!

Said he dropped one once and never found it!

Gotta be the smallest? Except for nano engines maybe.

Alistair Hosie
06-17-2008, 04:58 PM
your not paying attention Evan that's been shown already by sconisbee.:D Alistair

gmatov
06-17-2008, 11:47 PM
I did not see the links made before Evan's that sounded like the one I mentioned.

Had I clicked on one of them, and seen that Evan was late to the game, I could have joined you in scoffing at his post.

His was the first I clicked on, was the thread I mentioned.

That said, many years ago Diesel Mech in the US Navy, I love them big engines.

In my day, a 9 cylinder Sulzer, 3 X 5 foot put out 27,000 HP and they were the cat's meow.

102 RPM sounds like the old days, when they held emergency drills on Navy ships. Engineering officer runs down the ladder, tells the EM on duty that they just had an oil line rupture, what you gonna do?

EM on duty picks up a pump oiler, squirts the journals as they pass, "Oil pressure restored, Sir."

Fantastic machines, I don't care how much you love a CNC toy that can produce the tiny to larger parts you guys might make.

I'd rather run one of them than the MOST sophisticated CNC machine made.

I ran my Diesels, You put in a computer program and either it spits out parts off a bar, or you become a "feeder" keeping the machine spitting out parts.

Cheers,

George

lazlo
06-18-2008, 01:02 AM
While we cannot aspire to build a larger engine than the largest, someone might be able to build one smaller than the smallest.

Fun to compare George Luhr's engine with the Wartsila. 8 orders of magnitude difference in displacement :)

Luhr:
This single cylinder spark plug gas engine has a bore of 1/8" and a stroke of 5/32" and displaces only .0019 cubic inches.

Wartsila:
The cylinder bore is just under 38" and the stroke is just over 98". Each cylinder displaces 111,143 cubic inches (1820 liters).

This was also interesting:

Fuel consumption at maximum power is 0.278 lbs per hp per hour (Brake Specific Fuel Consumption). Fuel consumption at maximum economy is 0.260 lbs/hp/hour. At maximum economy the engine exceeds 50% thermal efficiency. That is, more than 50% of the energy in the fuel in converted to motion.

For comparison, most automotive and small aircraft engines have BSFC figures in the 0.40-0.60 lbs/hp/hr range and 25-30% thermal efficiency range.

Forrest Addy
06-18-2008, 02:20 AM
Don't know if my contribution here was already covered but I found these links searching for large engines:

http://www.vintagesaws.com/library/steam/steam.html

http://www.exploringthenorth.com/cornish/pump.html

http://www.kemptonsteam.org/engines.html

http://books.google.com/books?hl=en&id=xVggAAAAMAAJ&dq=largest+steam+engine&printsec=frontcover&source=web&ots=5MQwd1kwOv&sig=IgkdaNhi5-XOm8oclPyF9rfFevs&sa=X&oi=book_result&resnum=7&ct=result#PPR4,M1

http://www.youtube.com/watch?v=Tfd9oLzu3rI

http://www.usmm.net/engine.html

http://www.titanic-titanic.com/titanic_engine_room.shtml

Peter S
06-18-2008, 08:07 AM
Some large marine diesels do (or did) have flywheels. For example in one of my books the author is discussing problems he was having with a 1958 7 cylinder two-stroke diesel of 4,900 bhp. This engine had flywheels at both ends of the crankshaft, designed to "counteract the resonant phenomenon of torsional vibration". The aft flywheel was 11 tons, so pretty sizable.

BTW, the big 14 cylinder diesel pictured in the links above is a Sulzer, not Wartsila. Wartsila took over Sulzer, but the design of those big two-strokes is Sulzer (and built by others under licence). They are used in high speed container ships.

Trying to figure out the largest engine is difficult, because large could refer to power, height, weight, cylinder diameter etc. I guess the Sulzer is hard to beat on output, but there are still big triple expansion steam engines existing that are larger in other dimensions. For example you can see a 60 ft high triple (1000 hp) running at Kempton Park near London, and there are even larger (higher) survivors in the US (though not still running).

For cylinder size, it would be hard to beat the Cruquis engine in Holland with its 144" cylinder diameter; it still 'runs' too - though not on steam. I don't think the Ericsson hot air engine really counts, as it was a failure, whereas the Cruquis (and its two identical mates) were a great success.

Another engine still running with huge cylinder is the 90" beam engine at Kew in London - you won't forget the sight and sounds of this monster in action!

For the real mind-boggling giants of the steam age, you probably have to go back (in your imagination, no survivors I know of) to the 1870's and 1880's - this was when ships were rapidly growing in size and speed without any advancing development in marine engineering. Steam pressures were still low, higher pressures and triple expansion were still in the future - so compound engines were just made bigger. The largest were the tandem compounds - so large there was room for one only in the engine room, so high that they extended right into the skylight casings. Once the low pressure cylinders got to around 120", the limits were reached, so two equal-sized smaller low pressure cylinders were used instead.

Possibly even more mechanically impressive were the earlier side-lever engines used on the 'crack' paddle steamers that crossed the Atlantic in the 1850-era. Imagine being in the engine room of the Cunard steamers ‘Persia’, ‘Arabia’ or ‘Scotia', each with two side-lever engines. These engines used cylinders having around 100”-103” bore with 9’, 10’ and 12’ stroke, the four side levers were cast iron beams 6’6” deep in the middle and with 25 foot centres. With steam pressure around 22 psi, the largest were producing 4800 ihp, all engine control was by hand using teams of men – starting and reversing these engines was a dangerous business. Using up to 350 tons of coal per day, (all shovelled by hand naturally), these impressive but inefficient engines could give a ship speed of around 14.5 knots in 1862, a pretty quick (and reliable) way of crossing the Atlantic over 150 years ago.

lazlo
06-18-2008, 10:01 AM
I have a silly question -- how do you get an engine the size of the Wartsila into the ship? :)

Evan
06-18-2008, 10:28 AM
You build the ship around it.

Swarf&Sparks
06-18-2008, 10:50 AM
http://gcaptain.com/maritime/blog/the-wartsila-sulzer-super-engine/

Yup, you weld the decks over it. Like any other ship in the last 60 years.

Mind you, Pielstick do some reasonable plant too.
http://www.pielstick.com/merchant-marine/merchant-ships.htm

A.K. Boomer
06-18-2008, 10:52 AM
Good info Pete, my mind was comparing things to car terms and even though a 12 cylinder car is smooth as silk they still have a fair size flywheel, maybe for the most part just to give the clutch something to rub against:p
But it wasnt until Bart reminded me it was a two stroke, now as far as dead spots its more like a 28 cylinder instead of a 14. I can see why if you look at it that way -- also even though its just under 2 revs a second, can You imagine the max. ft.per.second and all that energy storage of the rods and pistons when at their 90 and 270 degree mark? Its kinda strange for me to think about engines that big, con-rods with built in ladders, I keep thinking to myself, Just get the ladders off and crank it up from 102 to 103 revs per minute:)

lazlo
06-18-2008, 11:16 AM
http://gcaptain.com/maritime/blog/the-wartsila-sulzer-super-engine/

Yup, you weld the decks over it. Like any other ship in the last 60 years.

So there's not much hope of replacing the engine, if the ship has a superstructure? On a container ship like the Emma Mærsk you can obviously just remove the deck plates and get to the engine...

Great link Lin -- notice the milling marks on the head. I'd love to see how they did that! :)

By the way, that link mentions that the Emma Mærsk (1,300 ft) isn't the largest ship in the world ;) So what engine does the Knock Nevis have?

http://bp0.blogger.com/_mmBw3uzPnJI/RcjhQe59BGI/AAAAAAAAAHU/4xUjRznFMig/s400/knock_nevis_001.gif

The Knock Nevis is a Norwegian owned supertanker, formerly known as Seawise Giant, Happy Giant, and Jahre Viking. She is 458 metres (1504 feet) in length and 69 m (226 ft) in width, making her the largest ship in the world. She was built between 1979 and 1981, damaged during the Iran-Iraq War, and refloated in 1991.

Swarf&Sparks
06-18-2008, 11:26 AM
"So there's not much hope of replacing the engine, if the ship has a superstructure?"

Cmon Laz, the average modern ship has a design life of 15 years!

Scares the sh1t outta me, a ULCC with a single engine/shaft/screw :(

lazlo
06-18-2008, 12:33 PM
Cmon Laz, the average modern ship has a design life of 15 years!

Oh wow, I didn't know that. I obviously don't know d!ck about ship architecture :) So do you just just run the ship 'till the engine self-destructs? I would imagine the hull and the superstructure could last for a long time with proper maintenance. The USS Kitty Hawk (aircraft carrier) was just decommissioned at the end of May, and it was commissioned in 1961 (i.e., 47 years).

The Knock Nevis/Seawise Giant/Happy Giant/Jahre Viking was completed in 1981, and is apparently still in operation?

Swarf&Sparks
06-18-2008, 12:39 PM
See the PM re the Kirki!
Oops, I see you have :)
Yup, most bulk carriers and tankers are well past their use by.
Why else would you register em in Liberia or Panama?


BTW, I wasn't aware USS Kittyhawk used Sulzers.

Rustybolt
06-18-2008, 12:44 PM
The ships owners balance what it costs to run over what it costs to maintain. The older the ship the more maintenance. After 15 years it costs more to keep it running than it's making.

Swarf&Sparks
06-18-2008, 12:49 PM
http://www.amsa.gov.au/marine_environment_protection/Major_Oil_Spills_in_Australia/Kirki/index.asp
But this one was still "running"
One of the guys, literally, put his foot through the deck of the Kirki when they jumped from the Lady Kathleen.
The lump of rust in his overalls pocket took pride of place in his home bar!

Evan
06-18-2008, 12:59 PM
So there's not much hope of replacing the engine, if the ship has a superstructure? On a container ship like the Emma Mærsk you can obviously just remove the deck plates and get to the engine...

There is a large and lucrative business in machining in place repairing ship engines. Must be an interesting job if you don't have family. Get a phone call and the next day you are anywhere in the world.

lazlo
06-18-2008, 01:11 PM
There is a large and lucrative business in machining in place repairing ship engines. Must be an interesting job if you don't have family. Get a phone call and the next day you are anywhere in the world.

I recently started watching the Discovery Channel "Deadliest Catch" serious about the Alaskan crab fishermen in the Baltic Sea.

This one guy had a major head failure on one of the two diesels, and when he returned to port, they paid $40,000 to repair a $60,000 diesel. They went back out to sea and the engine immediately died.

They're pulling in $1.5 Million in King Crab (on a good haul), so I'm guessing there was a lot more to the story about replacing the second engine. I.e., that the labor costs to cut open the ship to replace the engine was a lot more than the $60,000 for the cost of the engine itself.

By the way, there's a new series on the Discovery Channel from the same producers of "Deadliest Catch": it follows oil crews around. It's called "Black Gold." I think it starts tomorrow night, if anyone's interested. Looks dangerous as Hell!

sconisbee
06-18-2008, 02:02 PM
By the way, that link mentions that the Emma Mærsk (1,300 ft) isn't the largest ship in the world ;) So what engine does the Knock Nevis have?


Technically Knock Nevis isnt in operation as a ship, shes a stationary storage and offloading platform permanently moored in the Qatar Al Shaheen oil field. She has a steam turbine with a 2 stage reduction gearbox producing 50,000 horsepower driving a 5 blade 30 foot diameter prop and when fully loaded is to large to navigate the english channel.

Emma Mearsk is the one of the largest in actual operation however shes not the only one as she will eventually have 7 sisterships to the same specification (however im not sure of the number actually built so far)

wierdscience
06-18-2008, 02:11 PM
I recently started watching the Discovery Channel "Deadliest Catch" serious about the Alaskan crab fishermen in the Baltic Sea.

This one guy had a major head failure on one of the two diesels, and when he returned to port, they paid $40,000 to repair a $60,000 diesel. They went back out to sea and the engine immediately died.

They're pulling in $1.5 Million in King Crab (on a good haul), so I'm guessing there was a lot more to the story about replacing the second engine. I.e., that the labor costs to cut open the ship to replace the engine was a lot more than the $60,000 for the cost of the engine itself.

By the way, there's a new series on the Discovery Channel from the same producers of "Deadliest Catch": it follows oil crews around. It's called "Black Gold." I think it starts tomorrow night, if anyone's interested. Looks dangerous as Hell!

I've done that kind of work before,the $40,000 was a rape,prolly due to time and location.

Those crab boats are death traps,they get launched and they get ran,little else happens until they burn a shaft,blow an engine or sink.

Did you catch the episode where they had water coming in througha rust hole?Hulls are less than .50" thick,most are .375" which doesn't last to very many years in salt.

Last one I worked on was a 125' trawler,it had 11x16' water tight hatches in the deck over the engine/drive.Basically a section of deck cross ribbed and bolted in on a gasket with about 80 5/8" bolts,most of which wrang off.

sconisbee
06-18-2008, 02:45 PM
For those wanting to poke around the Wartsila engine a bit more check out this technology pdf from the company, and yes whilst they were designed by Sulzer they have been updated and upgraded for different applications and are technically sold under the Wartsila-Sulzer RTA96C for the one linked to, or in the case of the emma mearsk its the Wartsila-Sulzer RTAflex96C but for the most part are known just under the wartsila name.

Heres the pdf a fair few pics of the internals and details of the tech involved in the engine.
Technology Review (http://www.wartsila.com/Wartsila/global/docs/en/ship_power/media_publications/brochures/product/engines/low_speed/wartsila-RTA96C-engine-technology-review.pdf)

sconisbee
06-18-2008, 03:06 PM
The ships owners balance what it costs to run over what it costs to maintain. The older the ship the more maintenance. After 15 years it costs more to keep it running than it's making.

Unfortunatly ship owners and shipping companies "sometimes" push their luck a fair bit too doesnt happen often but sometimes..., there are some instances of ships that should have been decommisioned and broken up years ago but instead are patched up and reused, a prime example is the MSC Napoli that broke up not far from me, she was built in 91, and operated untill she ran aground at 22 knots and spent several weeks on a reef in 2001, which in many peoples opinions including the MCA over here should have been when she was scrapped, but she was refloated and repaired in vietnam including having 3000 tons of hull plating replaced before being put back into service. and then last year broke up in stormy seas near here, with a massive crack through her hull.

Swarf&Sparks
06-18-2008, 03:17 PM
Just had a quick google re "emma mearsk".
Wikipedia tells me she is a container ship.
Yes, no?
If she (it) is a container ship, there is little chance she will do great damage to the ports at which she calls.
(apart from the organisms in the ballast water, but that's another story) And, yes, container ships do carry ballast.

Back to the story. Most bulk, and especially oil cargoes, are carried by single engine/shaft/screw ships. Most, long past their use-by.

Flag of convenience vessels. Owned by "western nations".
Registered in Panama or Liberia. Not on Lloyds register, nor any other traceable insurer.

The bottom line?
:cool:

sconisbee
06-18-2008, 03:42 PM
Just had a quick google re "emma mearsk".
Wikipedia tells me she is a container ship.
Yes, no?


Back to the story. Most bulk, and especially oil cargoes, are carried by single engine/shaft/screw ships. Most, long past their use-by.


Yes she (it, sorry cant help it if i call a ship an it around cornwall ill be flogged! lol) is, biggest container ship out there.

And yeah the flag of convinience issue is a biggun there are *alot* of ships out there that shouldnt still be sailing but are. Its unfortunate, oh and funny you should mention ballast water my brother just finished doing a thesis on that for his degree:rolleyes:
Edit: napoli was a containership also, the risk their came from heavy fuel oils and ballast oils and that she was beached in a fragile area, but impact was greatly reduced and only light oils escaped the booms that were put around her if i recall right.

Anyway back to engines again, just how in the hell do you make such small engines like have been brought up in this thread earlier, i mean i wouldnt know where to start.

A.K. Boomer
06-18-2008, 04:01 PM
Anyway back to engines again, just how in the hell do you make such small engines like have been brought up in this thread earlier, i mean i wouldnt know where to start.



The rule of thumb I would use is take on the most difficult little piece possible, if you get it then the rest are within reach.

Evan
06-18-2008, 04:03 PM
By the way, there's a new series on the Discovery Channel from the same producers of "Deadliest Catch": it follows oil crews around. It's called "Black Gold." I think it starts tomorrow night, if anyone's interested. Looks dangerous as Hell!


I wonder if they will do one about tree fallers? I saw a news item a few nights ago showing how an experience faller drops a tree with a ten foot diameter and a couple of hundred feet tall. Tree Falling the is single most dangerous profession, bar none except maybe electric chair tester.

sconisbee
06-18-2008, 04:09 PM
The rule of thumb I would use is take on the most difficult little piece possible, if you get it then the rest are within reach.

Actually when you put it like that, it aint such a bad way to look at it lol, but even so must take some steady workmanship doing it, for now at least ill stick with bigger things lol, one day i figure i would like to try and build a tiny really complicated engine just so i can say "i did it" lol

Swarf&Sparks
06-18-2008, 04:12 PM
Well, der was dese tree fellers :D

Missed the point of the OP re small as well as large engines.
This is nice work
http://www.homemodelenginemachinist.com/index.php?topic=1879.0;topicseen

sconisbee
06-18-2008, 04:19 PM
not the smallest by far but these show some incredably refined workmanship
http://web.mac.com/lilenginebob/iWeb/Site/Some%20Tiny%20Engines.html

Swarf&Sparks
06-18-2008, 04:23 PM
Looks like damn fine work Sconisbee, but it's an irritating habit to use a coin as scale.
How the hell would we know what coin it is, let alone what size?

sconisbee
06-18-2008, 05:48 PM
lol i suppose he could have cheated and made a really big coin, instead of a really small engine!

egads i cant imagine having the patience to build something like that!

Peter S
06-18-2008, 06:00 PM
Just because a ship is huge (e.g. a tanker) doesn't mean it has an engine like the 14 cylinder Sulzer. The biggest Sulzers are found in large container ships which are built to make fast runs between Asia and the US or Europe etc. Other large ships, e.g. tankers and bulk carriers run at somewhat slower, more economical speeds and so have much more modestly sized engines. Back in the 1960's-80's there was a resurgence of steam turbine use, many of the largest ships, especially tankers, used turbines. Diesels were then developed to use the same cheap fuel as the boilers, so even this advantage was taken away from the steam turbine.

BTW, I saw a "Mega Structures" programme recently, it was about the building of a LNG carrier. This used steam turbines, though naturally there was nothing much on the programme about this. The film team had to do some searching, but eventually found some guy with a gas torch, grinder, hammer etc so they could get plenty of close-ups of sparks etc - you know, guys building a ship.... :(

wierdscience
06-18-2008, 06:40 PM
I wonder if they will do one about tree fallers? I saw a news item a few nights ago showing how an experience faller drops a tree with a ten foot diameter and a couple of hundred feet tall. Tree Falling the is single most dangerous profession, bar none except maybe electric chair tester.

History just finished their series "Axemen"-,fallers,highliners,riggers,skidders the works.

http://www.history.com/minisite.do?content_type=Minisite_Generic&content_type_id=57898&display_order=1&mini_id=57876

lazlo
06-18-2008, 07:34 PM
History just finished their series "Axemen"-,fallers,highliners,riggers,skidders the works.

http://www.history.com/minisite.do?content_type=Minisite_Generic&content_type_id=57898&display_order=1&mini_id=57876

Yep, Axemen was good, but nowhere near as good as Deadliest Catch. History Channel also had Ice Road Truckers -- about the Mackenzie River Ice Road in Canada, but somehow History Channel doesn't capture the ambiance like Discovery Channel :)

By the way "Black Gold" premier's tonight at 10 PM Eastern on TruTV and TNT-HD. I'm a little dubious if CourtTV can pull-off a documentary like this:

TONIGHT'S MIGHT-SEE: "Black Gold" debut, 10 p.m., Tru TV (formerly Court TV). As prices soar, the search for Texas oil becomes more intense. This reality series follows three rigs.

The Longhorn, 60 years old, was brought out of retirement; it's run by the crusty Gerald. The Viking is new and run by the easygoing Wayne. Big Dog is run by Tim, 31, and error-prone.

This is a world in which digits, limbs and lives are lost. Men work hard, drink hard, make big mistakes.

Evan
06-18-2008, 08:31 PM
And make big money. Because of the hazard they are paid at least $35 per hour for zero experience labourers and up from there. If they work overseas they also get contract completion bonuses that can be as much as 20% of pay at the end of the contract and often with no taxes.

lazlo
06-18-2008, 08:56 PM
And make big money. Because of the hazard they are paid at least $35 per hour for zero experience labourers and up from there.

Man, you should see the money the crab fishermen pull-in! On Deadliest Catch they post the totals for each ship when they return to port, and for the better ships/crew, they bring in ~ $50,000 each, for a 3-week season.

To put that in perspective, they're working almost non-stop (almost no sleep) for 3 weeks straight, in 40 - 50 ft waves and 70 knot winds, in sub-zero temperature. There's nearly 100% injury rate among the crew, and the mortality rate is 300 fatalities per 100,000.

Evan
06-19-2008, 12:18 AM
What I want to know is why being a garbageman is the fifth most dangerous occupation in the US.

Tim Clarke
06-19-2008, 12:53 AM
Well, I have worked at the local garbage co. for 29 years and change. During my time there, all of which was spent in the truck shop, I've seen a lot of good men cripple out.

I suspect that being a garbageman in the past was pretty risky. Now that the industry has, for the most part, embraced automation, the risk is falling really fast. In 1979 when I started, the guys were working 3 to a truck, with 1 driving, and the other 2 riding on the back of the truck, on steps, a risky enough place to be all on it's own. Over the years 2 guys were seriously injured when twits drove into the trucks, hitting the guys standing on the back. The guys rotated every hour, but the three of them would haul 750 stops a day, and maybe 12 tons or so. All carried on their backs in aluminum carrying cans weighing maybe 100 lbs when fully loaded. Then there's the risks involving frost, ice, and snow. [not much snow here] Not to mention agressive dogs.

The kids went to the resi dept. The old geezers ran the drop box and container trucks. A old geezer in the company in the 1980's was maybe 40.
There's so many ways for a garbageman to cripple out of the business, I can't even begin to remember all of them.

At our company, we went to automation when the new equipment was cheaper than the back surgeries. I suspect that there aren't too many garbagemen die on the job. Those that do are probably involved in truck crashes, a subect that I could write a couple pages on. Luckily, noone in our company has ever been seriously injured in a truck crash, but we don't run junk. Nevertheless, packing 8000 lbs of garbage on your back everyday thru rain and shine, year after year will eventually take it's toll.

TC

Evan
06-19-2008, 01:03 AM
There must be an upside though. People throw out some pretty valuable stuff at times. I have found all sorts of good stuff at the local dump that isn't garbage and isn't even broken.

oldtiffie
06-19-2008, 01:04 AM
Just to hi-jack the thread back to the OP - sort of - this pic came in by email yesterday.

It might not be the biggest piston in the biggest engine but it might go close to the biggest problem in one.

I wonder what the piston - and the crank-case - looked like!!

I have no other details.

http://i200.photobucket.com/albums/aa294/oldtiffie/Con-rod_problem1.jpg

Evan
06-19-2008, 01:18 AM
Ugg. It does help to remember that the larger you scale up things the easier they are to distort, bend, twist etc in relation to their size compared to the same item made smaller. That same old cube/square ratio works in favor of increased stiffness as the scale factor grows smaller. Eventually, if you try to scale up something indefinitely the mass of the object will produce enough gravity to collapse it into a black hole.

Willy
06-19-2008, 01:55 AM
Ouch!
Good one Tiffie, be nice to find the details of what happened alright.
Looks like a hydraulic lock...or too much nitrous.:D

A.K. Boomer
06-19-2008, 07:46 AM
Good picture Tiff, at first it had me begging for more but I can pretty much reassure you it was connecting rod bolt failure, What I cant tell you if its because it was over-reved or someone forgot to tighten it or it was defective or on and on, also, doesn't appear to be brought on by a spun bearing, (this is barring something obvious from the top end like piston seizure)
It took at least 2 full revolutions to finish off this train wreck,If this is a vertical two stroke diesel I can also pretty much reassure you that this engine could virtually run without a rod bearing cap except for one area - the exhaust stroke --- somewhere around 135 degree's is where the separation of rod and crank occured, the first revolution of the dearly departed went off without a hitch (pun intended) --- well almost -- You see there was still one good con-rod bolt trying so desperately to still do its job, but like one man trying to lift a couch at the end to be moved it was futile, the results were that this remaining rod bolt also let go, but before it did it flung the con-rod to the other side of the leading crank rotation edge (thats how those deep groves got cut into the rods beam surface -- they did it BEFORE the rod got bent) If we could see a different angle pic we would see identical scoring on the rods same beam side, this is from the cranks rod journal thrust flanges, Its also very easy to tell which cap bolt let go first as one will have a straight break and the other will have a bent arc at failure point -- the cap and rod can also give details, from the way this rod end was thrown into an advancement before the crank I would say it was the bolt in the picture that let go last, Not just because its bent - that could have happened in the chaos, but because it would be the one that would excell the big end in front of the cranks journal for those initial scores that happened on the beam, On to the second rotation --- on the first rotation the rod squeeks by with "minor" deformation -- for a split second all is well :p , but "it takes two to tangle" the con-rod stays clear until the cranks rod journal comes around to the bottom again, be it that the rod was static at that time or was still swinging from the last encounter the timing is of course all wrong for the journal to slip nicely into the rods opening, instead it catches a edge and the rod is forced into zero clearance with the crankcase -- then the big bend takes place, and that aint pot metal there fella;)

At first I thought there was an anomaly with the cross yoke, but I can see that those are oil ports and retention grooves,,,, a picture is worth a thousand words.

oldtiffie
06-19-2008, 07:53 AM
Thanks Boomer.

Good logical thinking and explanation.

I e-mailed the person I got the pic from for more info but he's hard to get a message to as his in-box is always full or else he is away or just forgets. He gets and sends heaps of e-mails.

If I get any more info I will post it as I'd like to see more of it and more of your analysis.

wierdscience
06-19-2008, 08:21 AM
Uh oh,somebody sucked a valve.

wierdscience
06-19-2008, 08:27 AM
Well, I have worked at the local garbage co. for 29 years and change. During my time there, all of which was spent in the truck shop, I've seen a lot of good men cripple out.

I suspect that being a garbageman in the past was pretty risky. Now that the industry has, for the most part, embraced automation, the risk is falling really fast. In 1979 when I started, the guys were working 3 to a truck, with 1 driving, and the other 2 riding on the back of the truck, on steps, a risky enough place to be all on it's own. Over the years 2 guys were seriously injured when twits drove into the trucks, hitting the guys standing on the back. The guys rotated every hour, but the three of them would haul 750 stops a day, and maybe 12 tons or so. All carried on their backs in aluminum carrying cans weighing maybe 100 lbs when fully loaded. Then there's the risks involving frost, ice, and snow. [not much snow here] Not to mention agressive dogs.

The kids went to the resi dept. The old geezers ran the drop box and container trucks. A old geezer in the company in the 1980's was maybe 40.
There's so many ways for a garbageman to cripple out of the business, I can't even begin to remember all of them.

At our company, we went to automation when the new equipment was cheaper than the back surgeries. I suspect that there aren't too many garbagemen die on the job. Those that do are probably involved in truck crashes, a subect that I could write a couple pages on. Luckily, noone in our company has ever been seriously injured in a truck crash, but we don't run junk. Nevertheless, packing 8000 lbs of garbage on your back everyday thru rain and shine, year after year will eventually take it's toll.

TC

Heh,my grandad used to tell me if I didn't stay in school I would end up on the back of a garbage truck.Some of those guys are making pretty good coin now,so maybe not too bad.

Evan
06-19-2008, 08:50 AM
Our first vehicle (Volks 1600 squareback) did the same thing with a broken rod cap. The rod ended up sticking out the side of the case. I didn't bother to fix it, we got about 80,000 miles for $600 to buy the vehicle. We bought an MGB instead. :D

kendall
06-19-2008, 12:41 PM
A buddy did the same while we were swamp running. I went through a couple deep spots, on the second one he found out that he had forgotten to tighten the lower clamps on the snorkel and pulled in a load of water. ended up with two rods bent. Had to pull him three miles back through the swamps and woods, then twelve to his house. Real nasty when you consider that we plan our routes for the most challenge.
Only one spot around here I havent run, and that -looks- like it's just a nice grassy feild, but if you walk out into it and stomp your feet the ground ripples and waves like throwing a stone in a pond.

ken.

A.K. Boomer
06-19-2008, 02:57 PM
The more I look at it the more I realize it could have gone either way, The length of the flat clearance on the side of the rod beam is why i say this, this means that the crank journals are almost as wide as the clearance of the inboard side of the cranks eccentric -- Yes im also in agreement that it could have hydrostatic locked and then when the rotation of the crank went to the negative and pulled back after bending it drew the top of the rod into the negative throws of the cranks eccentric leaving those furrows ----- if this is the way it went down then the procedure is the opposite of what I stated earlier, this way the rod got bent and then the furrows were formed, then the caps got yanked off...

Rookie machinist
06-19-2008, 06:00 PM
Ever have one of thoose "did I tighten that bolt" moments?

I live about 5 miles from the port of Long Beach and have heard the container ships backfire/misfire. First time I thought a bomb went off. I can only imagine the noise and vibration from that mess.

A.K. Boomer
06-19-2008, 09:45 PM
Its one of my biggest fears is leaving something loose, I cant recall anything that was a big deal but i'll knock on wood when I say that, Iv probably tightened millions of fasteners over the years, Sometimes you just cant remember the act of tightening it and it drives you crazy, had a customer take his car and then it always seems at night before I fall asleep I do a quick re-cap of all the jobs I did, couldnt remember tightening his front wheel lugs after a brake job, its 2 in the morning, I show up at his house with a 4 way lug wrench and start checking them in his drive, then his dog starts barking and a motion sensor light comes on, I peeled out of there, he never mentioned it and I really didnt want to tell him as its not exactly something that instills confidence:o --- the lugs ended up being tight - I fell right asleep after that.

Rookie machinist
06-19-2008, 11:28 PM
When I worked in the dealerships saw some good ones and I am just glad they were not done by me. Heres a few.
Front lower ball joint nut, came loose in front of the dealership.
Seen many lug nuts forgot or loose.
Brake caliper bolts left started by hand.
A/C pressure switch snap ring left off, turned it into a rocket.
Oil galley plug left out after rebuild, valdez part 2.
I could name many more I saw over the years, I was lucky and never had any big screw ups.

A.K. Boomer
06-20-2008, 12:12 AM
Caliper bolts --- I bet on the average I check at least 3 times, Over 30 years - like you I'll claim luck also but i also know that im very conscientious and thats the biggest factor going --- all you have to do is catch yourself one time in a "double check" and if its something serious then the seed of hightend awareness has been sown, then you start doing things like triple checking and quadruple checking and turn into a neurotic like myself:) Sometimes i even make a mental note when working and say to myself -- "now remember this so you dont have to go back and keep checking to see if you already did it"
Trouble is is im usually flying through it all and forget about the mental note, then go back and double check anyways -- think maybe I got a bad short term?

oldtiffie
06-20-2008, 02:39 AM
Thanks Boomer.

Good logical thinking and explanation.

I e-mailed the person I got the pic from for more info but he's hard to get a message to as his in-box is always full or else he is away or just forgets. He gets and sends heaps of e-mails.

If I get any more info I will post it as I'd like to see more of it and more of your analysis.

Hi Boomer.

I got an email back from the bloke who sent it to me. He got it as I did and he wants to know if I know any more.

Dead-end?

A.K. Boomer
06-20-2008, 09:43 AM
Yeah Tiff it would be interesting to hear the tale from one of the guys that was there, I have to show that pic to my bro's --- In formula V we had to do much detective work after the "crime" as an essential tool to find weak points and not repeat mistakes ect.
I have to admit Im leaning to the latter of my statements now as the first rely's on many things going off in "harmony" with the chaos,

Can some of you guys that have actually seen these engines tell me, where does that massive crossyoke mount up to the piston? The only thing im seeing where there could be a large enough mounting system is a through rod through the rod cap and mounted to the yokes pin -- is this where its at? this would explain the double rod bolts on that side??? And the cap would have to have a elongated oval in the middle so the con-rod can do its pivoting?
This would explain the out of proportion width of that upper rod journal in comparison to the lower one that failed.

A.K. Boomer
06-20-2008, 10:18 AM
Now I will jump to another contusion ------- I believe that its possible that the engine was in perfect "ship shape and bristle fashion"
All exceptin for one small detail, It was a diesel and it had an injector that had "bleedown", Be it overnight or after months of inop. the engine was started, There was by no means enough fuel to cause a hydrostatic lock, what happend is upon start-up other cylinders fired off first as they were first in line for the power stroke ticket show ----- then this poor slob was on his way up and his compression ratio set off the fuel that wasnt supposed to be there - way before TDC, the results were that the engine already had momentum AND had a few other cylinders Gang-banging the one that was trying so desperately to push the engine backwards, ooops, It was forced into trying to compress its own power stroke, it didnt work out very well.

Evan
06-20-2008, 12:23 PM
That is extremely unlikely. The vapor pressure of bunker fuel is nil. It won't form a combustible mixture unless it has been preheated and sprayed into compressed hot air.

GNO
06-20-2008, 07:48 PM
good idea to open indicator cocks and barr over the engine to check for hydro-loc.... I have spent some years w/ a 6000 hp nordberg it had wristpin oiling problems so....they added a approximet size 1 foot x 1 foot lead filled weight under the piston crown to throw the pistons against compression to allow oiling the wristpin [2 stroke]23"bore.

GNO
06-20-2008, 07:51 PM
PS an engine could have a cracked cyl. head and water could hydroloc the engine

sconisbee
06-20-2008, 08:16 PM
not to mention backflow from water injected exhausts causing hydrolock during starting trouble (depending on engine design i might add)

A.K. Boomer
06-20-2008, 08:59 PM
That is extremely unlikely. The vapor pressure of bunker fuel is nil. It won't form a combustible mixture unless it has been preheated and sprayed into compressed hot air.


Haaa- Tell that to my sheridan pellet gun --- it would fire off 3-1 oil if i used it to lube the piston slide, Not even bunker Fuel Ev, 3-1 --------- not even sprayed 3-1, just stagnant drops right from the little squeeze can, get about to the 8th or 9th pump and WHAM, it would about jerk your arm backwards, Fact ---
Give me a compression ratio high enough and I'll fire off a piece of swiss cheese, no joke bloke.

sconisbee
06-20-2008, 09:48 PM
Haaa- Tell that to my sheridan pellet gun --- it would fire off 3-1 oil if i used it to lube the piston slide, Not even bunker Fuel Ev, 3-1 --------- not even sprayed 3-1, just stagnant drops right from the little squeeze can, get about to the 8th or 9th pump and WHAM, it would about jerk your arm backwards, Fact ---
Give me a compression ratio high enough and I'll fire off a piece of swiss cheese, no joke bloke.

Not that im one to jump in and argue but Boomer has a point, there is a reason that on large marine diesels on startup (on some that i know of) have a procedure for cycling the engine without adding any further fuel to expel/use up what has accumulated in the cylinders. granted it may well be low risk but it is a procedure on some engines none the less.

fasto
06-20-2008, 09:50 PM
Years ago I was setting up the governor on a 3-engine ship (3 engines, one shaft). These were medium speed Pielsticks, 18 cylinders, 9,000 hp each. I got finished and asked the 2nd engineer to fire it up. We went up to the engine control room which looked out over the engine flat from the port side.
The 2nd engineer pushed the "autostart" button, the engine rolled over on air, the governor opened the fuel rack, the engine fired, "Oh S*** some doous left the blowdown cocks open!!! Quick hit the E-stop!!! Oh, no, the control air's not on!!!"
This V18 engine was idling happily along at 280 RPM with the blowdown cocks open, each shooting a 10-foot flame on each power stroke. No way to shut it down remotely. Did I mention that it was LOUD?
We bailed out of the ECR, I took a left up the ladder and the 2nd engineer ran down to the lower engine room to close the fuel rack manually, he holds the fuel rack closed and the engine stops.

sconisbee
06-20-2008, 09:59 PM
fasto, christ! i've heard tales similar but always third hand, sounds like a hell of a scare to be honest, i dont envy you being there at the time!, any damage caused?

oh and who left the cocks open? bet they got a bit of a telling off for that. why no control air just a forgotten step in procedure...or?

Evan
06-20-2008, 10:46 PM
aaa- Tell that to my sheridan pellet gun --- it would fire off 3-1 oil if i used it to lube the piston slide, Not even bunker Fuel Ev, 3-1 --------- not even sprayed 3-1, just stagnant drops right from the little squeeze can, get about to the 8th or 9th pump and WHAM, it would about jerk your arm backwards, Fact ---

3in1 isn't Bunker C. You can put out a fire with Bunker C. It has a flash point of 350 F. That means in order to form an explosive mixture in air it has to be heated to at least that temperature or enough won't evaporate to go bang. If there is a puddle of Bunker C heavy oil on the piston it isn't going to have time to heat up and vaporize in order to burn. The cyclinder will fire normally for the first couple of strokes and then it will start burning super rich. When that happens you get dense white clouds of smoke on startup.

sconisbee
06-20-2008, 11:16 PM
Again im not one to argue but Bunker C has a flashpoint between 71c and 117c also gives off a heavier than air vapour, almost any Bunker C MSDS sheets will tell you this.

but all of thats beyond the point and bringing the leading the topic away from the original as it was intended, so back to the small engines as i think large engines have been done to death

A.K. Boomer
06-21-2008, 12:00 AM
3in1 isn't Bunker C. You can put out a fire with Bunker C. It has a flash point of 350 F. That means in order to form an explosive mixture in air it has to be heated to at least that temperature or enough won't evaporate to go bang. If there is a puddle of Bunker C heavy oil on the piston it isn't going to have time to heat up and vaporize in order to burn. The cyclinder will fire normally for the first couple of strokes and then it will start burning super rich. When that happens you get dense white clouds of smoke on startup.


Evan, you need to do your research on fuels, flashpoint has nothing to do with it, Autoignition does, this is not a spark controlled engine, You can have an extremely low flashpoint (like gasoline -40 degree's F) and it can actually have a higher Autoignition rating than something with a much higher flashpoint -- like diesels 143 degree F flashpoint , Yes -- typical petrol will avoid lighting off with compression -- better than diesel -- its because its autoignition temp is 475 degree's F and diesels is 410 degree's ----- Now if you want to uphold an actual rebuttal tell me the autoignition temp of Bunker C. But that still wont help you as I will simply state that the engine obviously is designed to have the compression ratio enough to lite it off, No it wont be as effective as if it was misted and yes it has "some" protection because of that fact - but its still capable of going off. Is it a glow plug engine? Now this could help your defense -- still, many of diesel GP engines will start right up on a typical day...

Its important to remember that all you need is to get the top "skin" to ignite, then your little compression pressures turn into combustion pressures, it then feeds on itself as more pressure creates more heat and more heat creates more turbulent burning.

fasto
06-21-2008, 12:08 AM
fasto, christ! i've heard tales similar but always third hand, sounds like a hell of a scare to be honest, i dont envy you being there at the time!, any damage caused?

oh and who left the cocks open? bet they got a bit of a telling off for that. why no control air just a forgotten step in procedure...or?

I don't think anything was permanently damaged. It took perhaps 15 seconds from engine start to the 2nd engineer manually shutting it down. I suppose that the step of closing the blowdown cocks after barring the engine was forgotten as well as checking the control air. Actually, the engine control was not supposed to allow the engine to run unless control air pressure was available, perhaps the pressure switch was broken? We were restarting after a long layup and all the crew was relatively new... This might have been the ship with the hydraulic fluid in the air system, but I think that was on the ship that caught the shaft alternator clutch on fire.

It was a bit scary but I got in on bigger shipboard scares later. That's another of the reasons that I quit that job years ago.

Evan
06-21-2008, 06:39 AM
Evan, you need to do your research on fuels, flashpoint has nothing to do with it, Autoignition does, this is not a spark controlled engine, You can have an extremely low flashpoint (like gasoline -40 degree's F) and it can actually have a higher Autoignition rating than something with a much higher flashpoint -- like diesels 143 degree F flashpoint , Yes -- typical petrol will avoid lighting off with compression -- better than diesel -- its because its autoignition temp is 475 degree's F and diesels is 410 degree's ----- Now if you want to uphold an actual rebuttal tell me the autoignition temp of Bunker C. But that still wont help you as I will simply state that the engine obviously is designed to have the compression ratio enough to lite it off, No it wont be as effective as if it was misted and yes it has "some" protection because of that fact - but its still capable of going off. Is it a glow plug engine? Now this could help your defense -- still, many of diesel GP engines will start right up on a typical day...
You can't ignite fuel that isn't mixed with air. For that to happen it must evaporate if sitting in a pool as you stated. For that to happen it must be at the least warmer than the flashpoint.


Again im not one to argue but Bunker C has a flashpoint between 71c and 117c also gives off a heavier than air vapour, almost any Bunker C MSDS sheets will tell you this.
Except this one.





NO. 6 FUEL OIL

Material Safety Data Sheet



SECTION I PRODUCT IDENTIFICATION

Manufacturer's Name: Countrymark Cooperative, LLP
Address: 1200 Refinery Road
Mt. Vernon, Indiana 47620

Emergency Telephone Number: 812-838-8165 (Refinery Control Room)
800-424-9300 (CHEMTREC)

Trade Name: CO-OP #6 Fuel Oil
Chemical Name: Heavy Residual Fuels
Chemical Family: Hydrocarbon
CAS Registry No.: (See SECTION II)

SECTION III PHYSICAL DATA

Boiling Point (
o
F) 650 to 1200
Specific Gravity (H20 = 1) at 60o
F 0.95 to 1.00
Vapor Pressure (mm. Hg.) @ 60o
F < 10
Percent Volatile by Volume (%) None Expected
Solubility in Water Insoluble
Viscosity 45 to 300 SFS @ 122
o
F
Appearance and Odor:
Dark or black-colored high viscosity liquid requiring heated storage to enable pumping and preheating
at the burner to permit atomization. Material has distinct petroleum odor.

SECTION IV FIRE AND EXPLOSION HAZARD DATA

Flash Point (PM) > 150
o
F
Classification: Flammable Liquid NA 1993
Flammable Limits: LEL N/A UEL N/A__
Extinguishing Media:
Small Fires: Dry Chemical, Carbon Dioxide, water spray, or foam.
Large Fires: Water spray, fog, or foam
Hazardous Decomposition Products:
WARNING: Hydrogen Sulfide (H2S) and other hazardous vapors may evolve and collect in the
headspace of storage tanks or other enclosed vessels. Hydrogen sulfide is an extremely
flammable and highly toxic gas. Incomplete combustion may form toxic materials: Carbon
Dioxide and Carbon Monoxide, plus various unidentified organic hydrocarbons may be formed.
Special Fire Fighting Procedures:
Cool containers with water spray to prevent re-ignition.
Unusual Fire and Explosion Hazards:
Avoid heat, open flames, and oxidizing agents such as Chlorine, Permanganates, and
Dichromates.

http://countrymark.com/files/documents/msds/6_Fuel_Oil_0607.pdf


Note that the LEL and UEL are specified as NA, meaning not applicable. That's because it won't form an explosive mixture in air on it's own. It's too heavy. Note also it must be heated and atomized for it to ignite.

[edit]

Flashpoint isn't actually a specification value for Heavy fuel oil #6 (Bunker C). It's graded by viscosity and density according to ASTM D396-80 or BS 2869

oldtiffie
06-21-2008, 07:13 AM
Who said what fuel was used? It may be marine diesel fuel.

Evan
06-21-2008, 08:47 AM
The reason for using such large piston engines is that they are cheaper to operate IF they use bunker fuel.

Let's not lose sight of the point I was making. It is very unlikely that the damage was caused by a pool of fuel lying in the cylinder, not sufficient to lock the engine. Even if it were marine diesel it would not be in the appropriate mixture and atomization to ignite in such a destructive manner. Even if it did cause detonation a diesel is strong enough to withstand that.

A.K. Boomer
06-21-2008, 09:48 AM
You can't ignite fuel that isn't mixed with air. For that to happen it must evaporate if sitting in a pool as you stated. For that to happen it must be at the least warmer than the flashpoint.





Incorecto, unessesato, improper diagnoisioso ------- Now you need to go back to my REAL LIFE example of my sheridan pellet gun Firing off some 3 in1 oil, I dont know the flashpoint of 3 in 1 but I will tell you off hand that its very high as compared to typical fuels I will also state that the autoignition temp is way up there also, All typical fuels are mixed with air to varying degree's -- flashpoint is just a test method to when the mix gets critical enough to "travel" ---------- this effect is generally tested at room temp and @ normal atmospheric conditions --------- All typical fuels have a vapor "skin" on them, all typical fuels will lose much of their volatile mass just sitting out in the open, gas will totally disappear and turn to a thin layer of varnish, diesel will shrink and concentrate -- this will happen well below the temperatures of diesels flash point, All typical fuels just sitting in a jar are to some degree "mixed with air" actually most typical oils are also, Even thick Vactra way oil will shrink and harden if enough time goes by ;)
Fuels and oils do not need to be at a "flashpoint" temperature to give off fumes, in fact they can be well below, once again, flashpoint is key in determining if the mix is strong enough to "travel" -- whilst this is a handy tool for coming up with the proper grade of fuel for a spark ignition IC engine - it means absolutely nothing to a diesel --- diesels could give a rats ass if the mix can travel or not, the "skin" on top of the fuel (or oil) will get burned no ifs ands or buts --- all the diesel cares about is if the compression temp surpasses the fuels rated autoignition temp, if it does then its a guarantee'd fire-off.
Now, on to the power potential ---- it is my belief that if fuel was leaked slowly and ran on to the top of a cylinder head that had slight carbon deposits (think the surface area of a sponge rather than something glass smooth) and if the cylinders bores were sopping in the brew and if the top of the slightly carboned piston was sopping in the brew that there is allot of "skin effect" going on:) --- I know from personal experience that there can be huge power ---
My pellet gun was surprising to say the least --- after I hopped up the compression ratio I started having "trouble" after oiling ---- just like a typical engine when the crank is almost at TDC and the compression ratio is close to its highest - the crank has huge leverage over the piston --- the cranks speed has remained the same yet the feet per second travel of the piston is next to nothing, Even though my gun did not have a crank it was comparable in the fact that the closer you get to maximum compression the more leverage you have over it --- you would think that in no way could anything stop you -- you would be wrong, the 3 in 1 oil would fire off and abruptly send my arm back into the other direction,
If that mix didnt have an "out" and somebody tried to keep compressing it it would have broke the guns pump mechanism for sure, amazing power...

Willy
06-21-2008, 01:35 PM
A.K., the phenomena you experienced with your pellet gun is quite common in air guns who's piston is lubed with petroleum based oil.
I too have experience the kick back through the lever when the conditions were right. About the only thing I can compare the experience to is when kick-starting my bike and it let's off just before TDC and folds my leg in half. I have had it happen several times in the past, but after switching to a silicone based lube it has not reoccurred.

Here is a quote from Wikipedia describing the phenomena:



Modern air gun lubricants are generally a compounded mix of ingredients, such as silicone paste and molybdenum disulfide (http://en.wikipedia.org/wiki/Molybdenum_disulfide). These compounds are designed to not burn at the temperatures reached in airgun compression chambers, however it seems that any form of lubricant will burn to some extent at these elevated temperatures. Before the availability of synthetic lubricants, when purely petroleum based products were used, some writers claimed that upwards of 30% of the energy of the shot may have come from the burning of some of the lubricant [12] (http://en.wikipedia.org/wiki/Air_gun#cite_note-11) although this has been debated by others. The Cardews experimented by firing a spring-piston air rifle within a nitrogen-only enclosure, thus eliminating oxygen and preventing any form of combustion. The resultant shots fired displayed very noticeably reduced power when compared to the same setup fired both before and after the experiment outside of the enclosure, i.e. within the Earth's atmosphere. The limited burning of very small quantities of lubricant is not to be confused with "dieseling (http://en.wikipedia.org/wiki/Diesel)" which occurs when volatile fractions and vapours of petroleum-based lubricants burn violently, generally the result of excessive lubricant finding its way (or deliberately placed) ahead of the piston. This can and often does severely damage the spring and piston seals, and in extreme cases cause the cylinder to bulge, especially in modern, more highly stressed guns. Dieselling is noticeable also because the gun emits a very loud report, often comparable to that produced by a .22 Short (http://en.wikipedia.org/wiki/.22_Short) rimfire cartridge, some muzzle flash, and smoke


We can only speculate as to what actually happened in the photo that Tifie posted. Perhaps the original photo that he received would shed a clue if he clicked on the properties tab, this has helped me in the past when trying to find the source of a photo. As it stands now it has been renamed and does not offer any clues.

One doesn't have to be Sherlock Holmes to see that the engine was not operating under normal parameters for it to have bent the rod the way it did. I still subscribe to the hydraulic lock theory, whether it was fuel, water or ?.
On a side note about compressing foreign material in a ship's engine, I remember about twenty five years ago a large container ship while in port at Vancouver harbor was having it's combustion chamber de-carbonized by a worker inside the the engine. Well to make a long story short, someone violated safety protocols and lockout procedures and turned the engine over with the worker still inside, needless to say he looked worse than the bent con-rod.

Evan
06-21-2008, 03:51 PM
Read it again Boomer.

It is very unlikely that the damage was caused by a pool of fuel lying in the cylinder, not sufficient to lock the engine. Even if it were marine diesel it would not be in the appropriate mixture and atomization to ignite in such a destructive manner. Even if it did cause detonation a diesel is strong enough to withstand that.

A.K. Boomer
06-21-2008, 10:21 PM
Good read Willy, I was going to state that the next round out of the gun seemed a little more hopped up, It might get a little more past the check valve in the combustion chamber But due to the temperature's immediately cooling after (therefore pressures dropping) i dont think its a very dependable way of doing things properly with an airgun,
Evan, Im reading Willys article a little differently than you are, what Im reading from it is in small quantities it simply does not have the grunt, But the statement also basically says that "excessive lubricant placed ahead of the piston can cause severe damage to all kinds of the guns components"
Now --- once again --- thats just lubricant, what on gods green earth happens when you actually add some kind of fuel?

Here's a thought for you to chew on, if an entire combustion chamber on a diesel engine is doused with diesel fuel but yet the temperature is below "flashpoint" what happens to all those borderline fumes that couldnt quite be called "volatile" --- What happens when all those fumes congregate -- from say a space that had the surface area of 22 square ft and you condensed all those fumes into one square foot? Do you think they leave the room and go to heaven before the piston comes up?

Never underestimate surface area Evan, surface area alone has the ability to create a mist finer than the finest injection system out there;)

Evan
06-21-2008, 10:34 PM
Never underestimate surface area Evan
That only applies to substances that evaporate. Never underestimate the rules of physics. They never make exceptions.


Here's a thought for you to chew on, if an entire combustion chamber on a diesel engine is doused with diesel fuel but yet the temperature is below "flashpoint" what happens to all those borderline fumes that couldnt quite be called "volatile"
Below the flashpoint temperature a volatile liquid will NOT produce a combustible vapor concentration no matter how much surface area is present. That is why the specification exists.

edit: Note also that bunker C doesn't contain any volatiles.

J Tiers
06-21-2008, 11:17 PM
edit: Note also that bunker C doesn't contain any volatiles.

That's the important part.....

The stuff Evan posted the specs on is basically like TAR, and has to be heated just to pump it. Steam boiler fuel....... with steam lines in the fuel tank to heat it enough to flow to the ready tank for use.

That said, ANY burnable stuff CAN ignite. If you can't light it, it isn't fuel.

A.K. Boomer
06-22-2008, 12:34 AM
That only applies to substances that evaporate. Never underestimate the rules of physics. They never make exceptions.



Whats your time limit on evaporation, even vactra evaporates --- The rules of physics do make exceptions, they have to to be the rules of physics in the first place --- fact is Evan, Give me a compression ratio high enough and I'll fire off vactra, I'll turn it so warm within the compression that not only will i release its "fumes" but I'll also create autoignition with it


Below the flashpoint temperature a volatile liquid will NOT produce a combustible vapor concentration no matter how much surface area is present. That is why the specification exists.

See -- this is where you lose it, Flashpoint testing was more developed for the petrol engine, it relies on flashpoint - because it has too, it uses spark ignition, Once again, diesels slap flashpoint in the face, diesels utilize autoignition, most all fuels give off fumes, you mean to tell me bunker c has no smell -- BS --- it reeks, there you go, it has volatiles ---- Now try heating the crap out of it with an ungodly compression ratio --- think it just sits there (wrong)-- wet down one of those 220 sq. ft. combustion chambers let it sit overnight, and then compress it to 10 sq ft, It will light off if the engine is designed for the fuel and visa versa, dont think there's any power there? your greatly mistaken, Now take the temps and fuel vapor give off and even more pressures and then take that uncontrolled train wreck and of all things try to compress it --- good luck, Hell, Willy gave you an example of OIL destroying air guns, OIL,,,, how much fumes you think is coming off of that? One, Diesels dont give a crap, they will light it off ------ two, when it goes it can get much more of the mix involved than you think, look at the big picture here ------ where talking about an engine that redlines at just over 1 and 1/2 revs a second, think if something fired off it just might create some heat and extra pressure and that in turn would create more fuel which would in turn create more heat and extra pressures -- Getta the picha?


edit: Note also that bunker C doesn't contain any volatiles.

BS,

A little side note on over 30 years dealing with the diesel engine, you know that "popping corn" noise --- nothing is more critical than a diesels injection pump timing --- just 2 degree's in either direction can take you from a mild pop to a good god shut that thing off before it self destructs, Now think about being 30 degree's BTDC and having a mix go off, then think about compressing that mix ,,, thats where the tear drops start fella,
My bro blew the mill on his turbo diesel ford, I told his not to run it but he had to have propane injection --- It totally went against my way of thinking as you NEVER enter a fuel mix into a diesel and then compress it --- My bro said not to worry, hes got the beefy connecting rods, It ran like a stripped assed ape for awhile (he had a chip to) --- It never dissintigrated but it bent all 8 connecting rods and would not even idle because of all the side drag --- Rule of thumb, you can get by with a little pre-mature ejackulation but if you let it go to far and then actually try to compress the mix for some engines its all over in just that one misplaced stroke.

Evan
06-22-2008, 01:15 AM
See -- this is where you lose it, Flashpoint testing was more developed for the petrol engine, it relies on flashpoint - because it has too, it uses spark ignition, Once again, diesels slap flashpoint in the face, diesels utilize autoignition, most all fuels give off fumes, you mean to tell me bunker c has no smell -- BS --- it reeks, there you go, it has volatiles ----

Sure, it reeks. That only takes a few parts per million. In fact, if too much is present you can't smell it at all. That's what makes hydrogen sulphide especially deadly. You biggest mistake here it maintaining that if there is a low level of vapour present below the flash point then all it takes is to compress it to set it off. This is where you need to study basic theory of IC engines. If a mixture is too lean to burn compressing it doesn't change that. The ratio stays the same. A liquid fuel sitting in a pool below it's flashpoint may well emit trace volatiles. It will not however emit enough to make an ignitable mixture, compressed or not.

Autoignition requires a burnable mixture. It doesn't matter if you heat a mixture to double the autoignition temperature, if it is too lean or rich then it won't burn. Diesels don't slap anything except the odd piston. Flashpoint and autoignition temperature describe two different but related properties. You cannot have autoignition unless you have a fuel/air mixture. For that to happen you must either mechanically atomize the fuel or the fuel must exceed it's flashpoint so that it evaporates and forms a mixture within the LEL and UEL.

Swarf&Sparks
06-22-2008, 07:38 AM
Perhaps I can further muddy already turbid waters.

http://en.wikipedia.org/wiki/Fire_piston

Produced by "primitive" people with no machines. And tinder can hardly be regarded as volatile.

Evan
06-22-2008, 07:51 AM
Nothing muddy about it. It lights a bit of flammable substance with very hot air. I am quite sure that the tinder doesn't explode though. To do that it would have to be atomized in the correct mixture, same as a dust explosion.

Swarf&Sparks
06-22-2008, 07:54 AM
OK, point taken Evan.
I've worked in flour mills and cement plants (and several etcs that'd I'd rather forget)

A.K. Boomer
06-22-2008, 08:31 AM
Autoignition requires a burnable mixture. It doesn't matter if you heat a mixture to double the autoignition temperature, if it is too lean or rich then it won't burn. Diesels don't slap anything except the odd piston. Flashpoint and autoignition temperature describe two different but related properties. You cannot have autoignition unless you have a fuel/air mixture. For that to happen you must either mechanically atomize the fuel or the fuel must exceed it's flashpoint so that it evaporates and forms a mixture within the LEL and UEL.

One last effort, Willy's right on the money Air rifle "report" ; ---------- "dieseling" which occurs when volatile fractions and vapours of petroleum-based lubricants burn violently, generally the result of excessive lubricant finding its way (or deliberately placed) ahead of the piston. This can and often does severely damage the spring and piston seals, and in extreme cases cause the cylinder to bulge, especially in modern, more highly stressed guns. Dieselling is noticeable also because the gun emits a very loud report, often comparable to that produced by a .22 Short rimfire cartridge, some muzzle flash, and smoke"

Now -- tell me - what part of this statement are you having trouble with?
This is oil Evan --- not generally considered fuel ----- its destroying guns, not by being "atomized" -- but by just sitting there in the wrong place at the wrong time, You are very incorrect about a diesel actually giving a rats ass about some kind of optimal fuel/air ratio and that being necessary for "things to burn" Like I stated earlier --- autoignition does not discriminate in parts per million or even 14.7 to 1 ratio's ----- thats the petrol engine, The diesel doesnt care if there's one part of fuel hanging out in the middle of 1,000 parts of air -- all it cares about is that there is both, autoignition dictates that that single part of fuel will burn, It has too -- it has surpassed its ignition temperature and is surrounded by oxygen -- end of story, the same goes for a puddle of diesel sitting on top of a piston, there is a "skin" where this puddle meets air, there is oxygen in the air -- getta the picha?
This is why most of your modern day diesels dont even have a throttle plate, they control idle by injection quantity --- there fuel to air ratio is off the charts as compared to a gas engine, there taking in a FULL charge of air, and just spritzing a tiny little bit of fuel with it, imagine a gas engine using the amount of fuel it does at idle, but instead of it having an almost totally closed throttle plate for air intake its full bore open, Your most probably talking over a 100 to 1 fuel air ratio, You cannot run a diesel "lean" --- they are immune by design, you can however run too little of fuel in it to keep it idleing, and you can run too much fuel and surpass its oxygen capabilities of totally burning all of the fuel injected ------- thats where you will get that black soot coming out of the tailpipe......

A.K. Boomer
06-22-2008, 08:53 AM
Incidentally --- that last statement I talked about with diesels not having a throttle plate,,, many people dont realize that on a gas engine much of your driving happens at 1/4 throttle or below, and long cruises can actually be well below that like 1/8 throttle, But what this means for some diesel engines is there is tons of CFS going through them, in fact its more relative to RPM's than anything else --- so even at light duty cruise speeds your gobbling in air like a charging elephant, so much so that you need to keep an extra close eye on your air filtration system (thats why many rigs have a built in vacuum meter right on top of the filtration box, you can tell at a glance if the filter needs changing)
Not having a throttle plate has a few setbacks, in the winter time some engines cool so good that they actually have trouble keeping warm, Ford uses an exhaust restrictor to create loads of backpressure and "hold" heat in and stop the majority of CFS going through the engine.

J Tiers
06-22-2008, 09:08 AM
Explosion theories may be irrelevant to that failure, but....

It's worth noting that if there was any fuel in the cylinder, the compression ratio was HIGHER by the displaced volume RELATIVE TO THE NORMAL TDC volume.

That increased ratio would increase the TDC pressure and temperature, and may light difficult to light materials.

There IS a question as to how much a cold cylinder will reduce the temp of smaller amounts of oil etc that may be on the walls etc. Might not be possible to light that type amount, just by virtue of cooling.

But the relative low thermal conductivity of oils would probably allow the top of a *substantial* pool to be quite a bit hotter than the bottom.

If it is burnable, it will light. I didn't follow the one link, but I'd bet it is the maori fire tube, a very well-known compression fire-starter. Lights shredded tinder. Does NOT explode like gasoline, or a lot of Maoris would have the rod blown through their hands etc .............

The whole "flash-point" etc deal is interesting. In a way, there HAS TO BE a "flash point" in the sense of an *ignition temp*, or a material won't burn. Even WOOD has a flash point in that sense, and we all certainly know the "flash point" of paper, it is (supposedly) 451 deg F.

Some things that will NOT burn well in a pool or lump will burn/explode nicely in a spray or as dust. But "lighting" the material generally means getting it hot enough that part of it will be gasified, allowing oxygen to have access to the oxidizable molecules.

The "oil engines" which use a "hot cup" to gasify "heavy oil" (Hornsby-Ackroyd comes to mind, IIRC that engine is of that type) use extreme heat to evaporate the heavy oil and form a burnable mixture. I think their "heavy oil" is more of the nature of diesel, and NOT bunker C.

if it won't gasify, it won't "burn" (with a flame) it will only "smolder", i.e. burn on the surface.

A big lump of coal is darn hard to light with a match..... it won't happen, although it will light if tossed into a lit locomotive firebox. But grind it up and puff it into the air, and watch out....

In that specific case, the material is "effectively gasified" by being ground up, allowing oxygen access to all sides, in a small enough "piece" that "smoldering" is essentially equal to "flame burning" as far as speed of consumption.

Difficult-to-ignite fuel oils are sprayed for that very same reason.

But returning to the theory of the failure, with increased compression, there might have been lighting of the heavy oil, and it might not take much to create a problem.

With the amount of damage, you kinda think that there had to be a substantial *mechanical* cause.......

The con-rod looks to be around 0.7 meter square. And it doesn't seem long enough for Mr Euler to be a large issue as far as behavior in compression.

Theories about explosions in the cylinder etc are all very well, but that thing is REALLY bent....... And those engines are rather solidly built, probably able to withstand quite a lot of in-cylinder problems.

I'm not at ALL sure that I am "buying" any simple explosion theory of the failure.... I have to believe that there was a mechanical failure.
.
.
.
AK........

I'd be willing to bet that your air rifle was "carbureted"...... When you let in a blast of high pressure air, it WILL entrain oil and atomize some of it. That fits the bill of "breaking it into burnable pieces", and counters your arguments.
Sorry to burst the bubble.



thats where you will get that black soot coming out of the tailpipe

"smoke limited power"

fasto
06-22-2008, 12:32 PM
I looked again at that bent con rod.
It's clearly for a large crosshead design, probably 2-stroke, probably slow speed, like 70 to 100 RPM. Without additional details I don't think that we can figure out what caused it. (Keep in mind my experience is with medium speed engines, 500 to 1000 RPM redline).
I don't think it was small-scale hydraulic lock, the sort that is cleared by barring the engine over before starting; it looks far more smashed up than any hydrolocked engines I've seen.
I don't think it was a crankcase explosion; these usually happen after when the lube oil is being blown about and is well atomized.
I don't think it was preignition or detonation. I'd have to see the piston.
It's probably a mechanical failure of some sort. The turbo compressor wheel shed some parts, or the air-water intercooler had a massive failure filling the cylinder with water, or the piston came apart, or the piston pin came out & hung up, or a valve broke.
I think the most likely *single event* is a crosshead seizure, probably from lack of lube oil. Another possibility is a broken piston connecting rod (between the crosshead and the piston, not shown in the picture).

On further consideration:
One handy aspect of these slow speed engines is that they will run at reduced power with up to 1/3 of their cylinders out of operation. It's kind of like a limp-home mode. A cylinder can be taken out of operation by simply blocking the valves open and turning off the injector pump, or the piston, conrod & crosshead can be removed. Many times the lower conrod can be disconnected from the crank and blocked out of the way. Use of limp home is sanctioned by the engine builder, and instructions on how to implement it are included in the ship's on-board engine books.

The use of limp-home mode brings up another possibility: there are 2 events that caused the damage on display.
An initial event that caused the cylinder - usually called a "unit" - to be taken out of operation. This could be an injeciton pump failure, a cracked cylinder liner, or something else minor.
Then, a second event - such as the blocking holding the conrod out of the way failing with the engine turning under power - causing the massive damage.

A.K. Boomer
06-22-2008, 03:47 PM
.
.
AK........

I'd be willing to bet that your air rifle was "carbureted"...... When you let in a blast of high pressure air, it WILL entrain oil and atomize some of it. That fits the bill of "breaking it into burnable pieces", and counters your arguments.
Sorry to burst the bubble.




No bubble bursted JT, but lemmie pop yours:p It wasnt anything to do with when the air gets behind the pellet, it had to do with pumping compression into the hold chamber, this is by no means a "blast" of air pressure and is generally around 6 to 8 pumps depending on how much power you wanted out of the gun fir that particular round, its just a gradual step up of compression into the holding chamber , when the holding chamber exceeds the autoignition temp of the fuel or oil it is also is exceeded in the guns main compression/pump chamber, thats where the lube goes off and kicks the guns pump handle back at you like it wants to break your wrist.

J Tiers
06-22-2008, 07:11 PM
Yep just what I said....... I assume there is some valve there (of course) and any oil in the vicinity can be aspirated by the incoming air, to be potentially ignited on your downstroke.

The other poster referred to "boosted velocity"..................................

Simple stuff, simple answers.

A.K. Boomer
06-22-2008, 09:01 PM
Extremely simple stuff ------- My pellet gun has a piston and a bore which all have surface area, there is also release of "volatiles" within the stroke, (obviously even with lubricating oil) It directly mimmicks an internal combustion engines components in many a way, Yet You state; "That fits the bill of "breaking it into burnable pieces", and counters your arguments.
Sorry to burst the bubble."


It doesnt "counter my arguments" JT, It fuqeing verifies them:D


Get it together bro... or I'll give you a hand doing so:)

J Tiers
06-22-2008, 09:16 PM
Get it together bro... or I'll give you a hand doing so

Come and get what's coming to yah........ :D

To be very simple about it.....

You seem to argue that ONLY volatiles directly evaporating could POSSIBLY explain your noted phenomenon.

So, I simply proposed a simple mechanism using KNOWN facts about the gun by which the oil could ALTERNATELY end up as small droplets which could be ignited like any heavy oil spray. Volatiles not needed, although they certainly wouldn't hurt....

it DOES "counter" your argument that it "HAS" to be volatiles and ONLY volatiles, because it DOESN'T "have" to be volatiles if there may be a spray. it additionally uses facts that you yourself insisted on earlier....... that a spray is ignitable without volatiles, as with bunker C "oil".

The counter to any "single-possibility answer" is to offer an equally possible answer that is different.........

Obviously neither one of us can PROVE either mechanism.

oldtiffie
06-22-2008, 09:21 PM
For those that might have forgotten - or chose to ignore it - the OP was as follows:

Any chance of getting back to it??


Having recently finished my first steam engine (One of Elmers simple wobblers), and being a veteran insomniac, I was laying in bed the other night wondering just how small the worlds smallest piston engine is, and how large the largest one. I never messed around with model airoplanes, so really the smallest piston engine I have ever seen is the 3/8" diameter engine that I just built. I have seen pictures of really large engines in trans Atlantic ships, and I am curious ---would the largest piston engine be something current, or would it have been built at the time of the industrial revolution. I don't care if it was steam, gasoline, or diesel---long as it was a piston engine.

J Tiers
06-22-2008, 10:50 PM
For those that might have forgotten - or chose to ignore it - the OP was as follows:

Any chance of getting back to it??

Eh, some nerve they have down there....... Tiffie posted the picture that started all this! ;) :D :rolleyes: :eek:

oldtiffie
06-22-2008, 11:35 PM
Sorry JT - nothing personal and not directed at you personally.

We have no nerve here "down here" - shot to pieces with the booze etc. etc. ......................!!

It was getting personal - and perhaps some needed to draw breath - even if to smell the roses.

I have no problems with the "techo" stuff - pretty well no matter where it leads to/from in any of its guises or permutations.

Some may well react to fuel fumes the way some people I know react to the smell of cordite and the sound of gun/cannon-fire - and its not pretty.

J Tiers
06-23-2008, 12:17 AM
Not a problem......

Personal? Maybe, AK seemed to be morphing into AK-47........ But we'll probably all live to see the dawn...

I have no idea how to write Arabic to show up here, or I could maybe insert something particularly apropos. But likely few would appreciate it.......

In any case, it's all fun here.... and if they can't take it, give 'em the ashes and move on!

A.K. Boomer
06-23-2008, 01:38 AM
JT, sorry bout the misunderstanding --- I was kinda morphing because I had to paint today, i hate body work ,,, anyways - I dont recall ever saying that there HAD to be volatiles - I thought that was more of evens argument, what I was saying is that volatiles can be released on demand due to the extreme temps and this can also have a snowball effect as the more thats burnt the more heat and pressure are created, I think allot of people think that the lower the flashpoint means that things will go off easier with autoignition, I think its kinds strange for some to think of gas having a flashpoint of -40 and diesels being 143 yet the diesel lights off earlier under compression 410 to petrols 475, I brought that up way early as a point about volatiles, all volatiles are not created equal.

oldtiffie
06-23-2008, 07:44 AM
Not a problem......

Personal? Maybe, AK seemed to be morphing into AK-47........ But we'll probably all live to see the dawn...



JT - brilliant - that is one of the best "one-liner's" and "put-downs" I've ever seen - even Winston Churchill would not have topped it!!! I'm still chortling over it.

And thanks Boomer for taking it in good humour and like a man - just as well done.

A lesson to us all from both JT and AK.

J Tiers
06-23-2008, 08:03 AM
I must have mixed up the arguments...... it DOES get a bit complicated after a while..........

Flash point is one thing, but depends on an actual ignition source being present. A cup and lighted string is one test method......

The compression ignition deal is different, as there isn't a flame present. Cetane / octane ratings are related to the compression ignition capability, as well as the burn rate, but I believe they are not directly related to each otehr, nor to the flash point.

However, at some point in one of these discussions there was a "heated" discussion of model diesels (non-glow plug), with mention of using very volatile and low flash point substances (ether) as the igniting compound. The compression ratio is variable in those engines, 'tuned" by the counter-piston position.

Presumably there is a tendency for such materials to "light off" in compression ignition engines, or the ether wouldn't be useful... But then, ether will 'go off" VERY easily.

if gas was as good as ether, it might be used to start balky diesels...... or perhaps the ether is just ignitable yet low in actual POWER of explosion..... the goal is to start, not blow holes in things...

Peter S
06-23-2008, 09:07 AM
If it is burnable, it will light. I didn't follow the one link, but I'd bet it is the maori fire tube, a very well-known compression fire-starter. Lights shredded tinder. Does NOT explode like gasoline, or a lot of Maoris would have the rod blown through their hands etc .............

J,

Dunno if the Maori ever had them, I don't think so. The diesel books I have reckon the "firestick" were an ancient southeast Asian or Chinese idea. Rudolf Diesel saw one demonstrated when he was a polytech student - it made an indelible impression on him, and apparently he used one years later to demonstrate how his engine worked to his own children.

Here is a photo of the heavy-glass-walled firestick from Diesel's schooldays (from "Diesel's Engine" by Lyle Cummins).

http://img.photobucket.com/albums/1003/PeterS/DSCN0262.jpg

BTW, I can't imagine any hydraulic lock bending a con rod like that. I have seen a D8 bent conrod - it wasn't much of a bend, just enough to make it miss on that cylinder when cold... I reckon a good bend like that happens when it comes adrift of the crank pin and then gets well and truly mashed by the crankshaft.

oldtiffie
06-23-2008, 09:26 AM
Peter,

good read.

S&S provided the link - a very good read - that you require for the South-Sea and Asia "fire stick" and info on Mr. Diesel at:


Perhaps I can further muddy already turbid waters.

http://en.wikipedia.org/wiki/Fire_piston

Produced by "primitive" people with no machines. And tinder can hardly be regarded as volatile.

A.K. Boomer
06-23-2008, 10:05 AM
I looked again at that bent con rod.
It's clearly for a large crosshead design, probably 2-stroke, probably slow speed, like 70 to 100 RPM. Without additional details I don't think that we can figure out what caused it. (Keep in mind my experience is with medium speed engines, 500 to 1000 RPM redline).
I don't think it was small-scale hydraulic lock, the sort that is cleared by barring the engine over before starting; it looks far more smashed up than any hydrolocked engines I've seen.
I don't think it was a crankcase explosion; these usually happen after when the lube oil is being blown about and is well atomized.
I don't think it was preignition or detonation. I'd have to see the piston.
It's probably a mechanical failure of some sort. The turbo compressor wheel shed some parts, or the air-water intercooler had a massive failure filling the cylinder with water, or the piston came apart, or the piston pin came out & hung up, or a valve broke.
I think the most likely *single event* is a crosshead seizure, probably from lack of lube oil. Another possibility is a broken piston connecting rod (between the crosshead and the piston, not shown in the picture).

On further consideration:
One handy aspect of these slow speed engines is that they will run at reduced power with up to 1/3 of their cylinders out of operation. It's kind of like a limp-home mode. A cylinder can be taken out of operation by simply blocking the valves open and turning off the injector pump, or the piston, conrod & crosshead can be removed. Many times the lower conrod can be disconnected from the crank and blocked out of the way. Use of limp home is sanctioned by the engine builder, and instructions on how to implement it are included in the ship's on-board engine books.

The use of limp-home mode brings up another possibility: there are 2 events that caused the damage on display.
An initial event that caused the cylinder - usually called a "unit" - to be taken out of operation. This could be an injeciton pump failure, a cracked cylinder liner, or something else minor.
Then, a second event - such as the blocking holding the conrod out of the way failing with the engine turning under power - causing the massive damage.


Good Info Fasto, Yes many of possibility, Im leaning to the side that because its such an expensive issue that most all critical things where triple checked and someone got caught on a technicality/fluke (but then again look at nasa:rolleyes: sometimes the more money and people involved the worse things can get)

I think many things are possible for sure -- Evan has brought up the point of diesels being able to handle compressing a pre-mature stroke, I believe it depends on the engine and also how pre-mature and powerful the stroke is -- and will also throw into the mix one of his first statements of;

" Ugg. It does help to remember that the larger you scale up things the easier they are to distort, bend, twist etc in relation to their size compared to the same item made smaller."


This is a huge factor, but its also something that I do not have the ability to do the math on or have all the engines material and design specs to begin with,

Someone out there knows exactly what happened ------ to bad there isnt a search engine for pictures --- or is there? if not why not?

A.K. Boomer
06-23-2008, 11:57 AM
Quick side note, while the crossyokes rod beam in the picture looks intimidating and it is indeed very strong in a direct compression analogy its important to realize that you cannot by an engineering standpoint look at the rods beam in this way, more so the rod has to be looked at with a slight bend, this bend is directly dependent on the force that is exerted on it, due to the nature of the cranks eccentric and the yokes pivot pin under extreme loads what happens is the lower part of the rod creates much drag on the rods bearing this in turn try's to rotate the entire rod as a unit, this however cannot occur as the rods upper part is held in place by the crossyoke pin, so the result is - is not only does the lowest part of the rod get loaded in the direction of the cranks rotation, the upper part of the rod trys to bond more with its pin and resist --- both work simultaneously to bend the rod in opposite directions, but the crank is the drive mechanism and has much more force at the base of where the rods big end meets the beam, with a rod thats already dealing with extremes in load sometimes all is needed is a little push to get things going, With this example one can see how a misplaced combustion stroke can get the ball rolling, allowing both the power from the stroke and the twisting /drag forces of the crank to rod and rod to pin to help finish it off, When you think about it -- its kinda strange to see a rod without a beam, Just because its an engine that incorporates a cross yoke system does not mean that its immune to these forces, there is a reason for that massive wide beam on the bottom of a con-rod and this is one of them,

To get an Idea of what im talking about look at Tiffs picture, I know its kinda diagonal - but- if the side were viewing of that yoke was facing foreward ( or whatever you use to call forward on a ships engine of that size and judge its components from therein) Then the engines (cranks) direction would have been CCW, Not that the part of the yoke was facing "forward" (or whatever you use) -- but - if it was. Think I just confused myself:p