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View Full Version : What to do with a ground power unit, aircraft junk?



The Artful Bodger
04-04-2012, 01:10 AM
We (our aviation museum) have a ground power unit that I think was used in the day for ground power for DC8s.

It has a Detroit(?) two stroke straight six diesel, I cant remember the number but it is in the '600' series. The engine fires up and runs well with no smoke. 11000 hours on the clock.

The three phase alternator is low volts 120/208 400Hz 75KW.

Everything is mounted on a nice four wheel cart of the type used at airports and presumably not suitable for road use with its small wheels.

So what to do with this? Sell the engine and scrap the alternator? Fit it up with a bunch of flood lights? Make a carbon arc search light?

Really, what can be done with 400Hz power (except start aircraft)?

hardtail
04-04-2012, 02:12 AM
Sounds like a 671......really no smoke at all.......grin

The Artful Bodger
04-04-2012, 02:20 AM
Sounds like a 671......really no smoke at all.......grin


Hmmm, not sure I understand!;)

camdigger
04-04-2012, 02:25 AM
Sounds like a 671......really no smoke at all.......grin

75KW = +/- 100 hp. about right for a genny match for a 671 GM aka Detroit Diesel.

Is there a super charger on it? The 671s I worked around had roots blowers on the intakes. Most were poorly muffled and earned the nickname "screaming jimmies". Most commercial diesels from the era of the 600 series were oil slobbering/leaky beasts. So much so that the running joke was the oil never needed to be changed just topped up with every tank of fuel.

As I recall the "series number" refers to the number of cylinders 600 being an inline 6. There were anumber of 6v53s around too.

GM made 5 or so basic cylinder sizes including 53, 71, 92, 135, and 155. These cylinder sizes were put in blocks configured from straight 3 cylinders to v16 blocks. 353 were about 60 HP IIRC and the 12v92 was roughly 600 HP IIRC. Because of their relatively high HP to weight ratio, they were a favorite for mobile equipment. Only in the last 5 years or so have the big 8v 155s been replaced by electronic controlled inline 6s on high HP pumpers.

Black Forest
04-04-2012, 02:33 AM
What he is referring to when he says "no smoke at all" is that you would be the proud owner of the only Detroit that doesn't smoke, burn or drip oil!

We used big air compressors that had Detroits. The sound of those babies on start up was great. The earth shook and I got goose bumps every time from the roar! I loved them. We rebuilt many of the 400, 600, 800 series. I like those diesels.

Doc Nickel
04-04-2012, 02:34 AM
I have a pair of old Davies (I think) flightline air compressors- on similar trailers- that take 440 volt (and, I've suspected, 400hz.)

In the flip up control panel lid, there's a set of instructions, and step #7 or so, says something like "connect high pressure line to missile body". Which makes me think they used to be part of a Nike or Hercules AA missile battery, which we had a couple of up here, back in the fifties and sixties.

I'll let ya have 'em cheap. Then you can have all the 2200 psi air you could want. :D

Doc.

The Artful Bodger
04-04-2012, 02:38 AM
Yes, 100hp would have to be about right.

There is a roots type blower on intake, left side of the engine, surmounted by two large(ish) air cleaners.

It is well muffled and it sure does sound to be running fast but I assume thats because its a two stroke and six cylinders.

I should have taken note but I am fairly sure the number begins '600' and if I recall correctly the entire number is '600655'.

BTW, I am probably wrong in thinking it was used for starting DC8s as I now remember that they had 'air carts' for that job. But they were likely used for aircraft power (lighting, air con etc) while un/loading passengers etc.

The Artful Bodger
04-04-2012, 02:40 AM
What he is referring to when he says "no smoke at all" is that you would be the proud owner of the only Detroit that doesn't smoke, burn or drip oil!

We used big air compressors that had Detroits. The sound of those babies on start up was great. The earth shook and I got goose bumps every time from the roar! I loved them. We rebuilt many of the 400, 600, 800 series. I like those diesels.


However our Detroit is only one of several that have blown a bird's nest out when first started!:p

The Artful Bodger
04-04-2012, 02:43 AM
I have a pair of old Davies (I think) flightline air compressors- on similar trailers- that take 440 volt (and, I've suspected, 400hz.)

In the flip up control panel lid, there's a set of instructions, and step #7 or so, says something like "connect high pressure line to missile body". Which makes me think they used to be part of a Nike or Hercules AA missile battery, which we had a couple of up here, back in the fifties and sixties.

I'll let ya have 'em cheap. Then you can have all the 2200 psi air you could want. :D

Doc.


Oh dear! Being a bone fide all-volunteer, entry-by-donation, museum we are honour bound to accept all offers of 'things' for the museum!:p

macona
04-04-2012, 06:19 AM
Rectify it to DC and then run and inverter off it to get the power you want. Some things won't care, like lights and heaters with no inductive parts. Things with switching power supplies will probably run just fine though.

Doc Nickel
04-04-2012, 06:30 AM
Oh dear! Being a bone fide all-volunteer, entry-by-donation, museum we are honour bound to accept all offers of 'things' for the museum!:p

-Pay for shipping and I'll crate 'em up for you within the week. :D

Doc.

The Artful Bodger
04-04-2012, 06:31 AM
-Pay for shipping and I'll crate 'em up for you within the week. :D

Doc.

Thanks Doc, I will get back to you on this...:)

The Artful Bodger
04-04-2012, 06:38 AM
Rectify it to DC and then run and inverter off it to get the power you want. Some things won't care, like lights and heaters with no inductive parts. Things with switching power supplies will probably run just fine though.


It is a bit early yet but in not much time, just a few years, almost everything in the typical house will be 'frequency independent'.

Peter S
04-04-2012, 07:08 AM
Make a few of these?

1939 1-71, for sale on Trade Me at present.

http://img.photobucket.com/albums/1003/PeterS/th_1-71193902.jpg (http://smg.photobucket.com/albums/1003/PeterS/1-71193902.jpg)

http://img.photobucket.com/albums/1003/PeterS/th_1-71193905.jpg (http://smg.photobucket.com/albums/1003/PeterS/1-71193905.jpg)

EVguru
04-04-2012, 07:35 AM
We (our aviation museum) have a ground power unit that I think was used in the day for ground power for DC8s.

It has a Detroit(?) two stroke straight six diesel, I cant remember the number but it is in the '600' series. The engine fires up and runs well with no smoke. 11000 hours on the clock.

The three phase alternator is low volts 120/208 400Hz 75KW.

Everything is mounted on a nice four wheel cart of the type used at airports and presumably not suitable for road use with its small wheels.

So what to do with this? Sell the engine and scrap the alternator? Fit it up with a bunch of flood lights? Make a carbon arc search light?

Really, what can be done with 400Hz power (except start aircraft)?

I've got a pair of 25Kw alternators on the shelf (ruputedly from F100s). They were very sought after by the electric vehicle community because with manual control of the field you could get anything from around 12 to 208+ volt. With the output rectified they made ideal fast chargers or range extenders for EVs.

wierdscience
04-04-2012, 10:01 AM
Make a few of these?

1939 1-71, for sale on Trade Me at present.

http://img.photobucket.com/albums/1003/PeterS/th_1-71193902.jpg (http://smg.photobucket.com/albums/1003/PeterS/1-71193902.jpg)

http://img.photobucket.com/albums/1003/PeterS/th_1-71193905.jpg (http://smg.photobucket.com/albums/1003/PeterS/1-71193905.jpg)


Oh those are nice,even better would be the ones with Delco alternators on the back.

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

lakeside53
04-04-2012, 12:03 PM
What he is referring to when he says "no smoke at all" is that you would be the proud owner of the only Detroit that doesn't smoke, burn or drip oil!




Yep.. they are not called Driptroits for nothing! I suspect it has simply run out of oil.:D

lakeside53
04-04-2012, 12:09 PM
Rectify it to DC and then run and inverter off it to get the power you want. Some things won't care, like lights and heaters with no inductive parts. Things with switching power supplies will probably run just fine though.


Switches and contactor contacts will care greatly! Pay attention to the "DC" ratings of such - way way lower than AC.

Lights and heaters can generally run of 400hz with no issues, generally.... but, few items other than military and aviation will be "labled and listed" for such use (if you care).

Turn it into a 100kw "backup" hanger heater.

The Artful Bodger
04-04-2012, 03:58 PM
Ha ha, the only oil on the ground is from when someone lifted an air cleaner off without draining the oil first and I am sure the lack of smoke is entirely due to the fantastic maintenance regime this machine enjoyed throughout its service life!:D

No, we wont be trying to rectify 70+KW [thinks] hmmmmm, I know some people running a tramway museum and they have rather cool (to look at) mercury arc rectifiers...... makes one think of possibilities.

We dont really need a hangar heater in this climate...neither do we need air-con. Good point about a heating load, maybe we can build it into a portable grain dryer and raise some funds with it that way.



I assume VFDs are in the same category as SMPs and would be happy on 400Hz?

The Artful Bodger
04-04-2012, 04:02 PM
I've got a pair of 25Kw alternators on the shelf (ruputedly from F100s). They were very sought after by the electric vehicle community because with manual control of the field you could get anything from around 12 to 208+ volt. With the output rectified they made ideal fast chargers or range extenders for EVs.

I know someone who collected old city trolley buses and use to drive them around town towing an old military mobile generator.

macona
04-04-2012, 04:30 PM
Switches and contactor contacts will care greatly! Pay attention to the "DC" ratings of such - way way lower than AC.

Lights and heaters can generally run of 400hz with no issues, generally.... but, few items other than military and aviation will be "labled and listed" for such use (if you care).

Turn it into a 100kw "backup" hanger heater.


Ahh, no I meant running the lights and heaters on 400, not DC.

macona
04-04-2012, 04:33 PM
I assume VFDs are in the same category as SMPs and would be happy on 400Hz?

Yes, they ought to. The first thing that happens is it is rectified to DC. At that point DC is pretty much DC. Just with a 400Hz input there is going to be less ripple, which is always a good thing.

justanengineer
04-04-2012, 04:42 PM
Is there a super charger on it? The 671s I worked around had roots blowers on the intakes. Most were poorly muffled and earned the nickname "screaming jimmies". Most commercial diesels from the era of the 600 series were oil slobbering/leaky beasts. So much so that the running joke was the oil never needed to be changed just topped up with every tank of fuel.


I was always under the impression that the reason Driptroits were nicknamed "Screaming Jimmies" was because of the revving capability of the engine itself - the engines were built well enough that they could rev right up to the point of where the blower would lose its smoke. Jet A + BIG injectors + BIG fuel pump = a scarey RPM for a big engine.

I think some of the nicknames have kind of killed the reputation in error. Theyre not necessarily my favorite diesel, but most I have dealt with were simple, solid, and reliable. Also not necessarily the highest tech, ala the slobber tubes and their constant "drip," but definitely good engines and no more prone to leak than anything else.

The Artful Bodger
04-04-2012, 05:27 PM
Yea, well, maybe, this one sure sounded like it was revving its heart out but just a glance at the crank pulley showed it was actually turining quite slowly.

With six bangs per revolution even 1750rpm sounds fast.

jdunmyer
04-04-2012, 06:50 PM
A Detroit Diesel engine is the most efficient device known to man for converting Diesel fuel into noise, bar none.

I like that little one-cylinder outfit, it'd be neat to own. My John Deere backhoe has a 2-53 Detroit engine. Very loud, quite economical on fuel.

Another quirk of the Detroit is that they'll run away, burning their own lube oil if the rings are bad or if the blower seals are shot. Most of them have a spring-loaded "choke" in the air intake connected to a button near the operator's position. That's the emergency shutdown. Folks unfamiliar with the Detroit will sometimes trip the mechanism and can't figure out how to get 'er started again. The thing requires manual resetting, sometimes using a Channel-Lock pliers or equivilant.

The Artful Bodger
04-04-2012, 07:06 PM
I expect there would be few, especially 2 stroke, diesels that will not run away if worn enough to ingest lube oil.

Even the old Lanz tractors (10 litre, single cylinder, 2 stroke) were known to do this if the oil 'baler' in the crankcase failed. The technique then was to select top gear and drop the plough in the ground, at which point the engine would falter, backfire and the tractor would jump backwards onto the plough. Ah, such fun days as a boy on the farm!;)

Willy
04-04-2012, 07:42 PM
...........

I think some of the nicknames have kind of killed the reputation in error. Theyre not necessarily my favorite diesel, but most I have dealt with were simple, solid, and reliable. Also not necessarily the highest tech, ala the slobber tubes and their constant "drip," but definitely good engines and no more prone to leak than anything else.

This has been my experience as well. Having spent several thousand hours each with 8V71 and 8V92TA's I can attest to their reliability and the fact that they should not leak if in good mechanical condition.

Where the leaking and slobbering reputation comes from is from engines that are well worn beyond services limits and lack of proper lube and or maintenance schedules.
When a combination of these conditions exist they do exhibit a propensity to leak oil from the air box drains.
And yes being a two stroke they do sound as though they are screaming.
At 2100 rpm the exhaust does indeed sound like 4200 rpm.

Detroit Diesel two strokes that are generally encountered are referred to by their cubic inch per cylinder designation. These engines from a 'series' are are all from the same family and share a lot of internal components between them within a 'series'. Although they share a basic architecture among each other, due to size parts usually do not interchange from one series to another.

Detroit Diesel nomenclature for these engines designates the first number to the number of cylinders, the second number refers to the series or cubic inches per cylinder. This encompasses 53, 71, 92, and 149 cu.in./cyl.
Within a series a 'V' between the cylinder number and series number indicates an engine with a V configuration. Engines without the V are in line.
The 'T' and or 'A' after the series number signifies the engine is turbocharged and or after-cooled.

What is often referred to as a supercharger on all of these engines is actually a scavenge blower that the engine requires in order to operate, it produces very little positive pressure by itself. Hence the use of turbochargers for these engines in order to give positive boost pressures.
The scavenge blower is often either pirated from these engines or copied and used by hot rodders as a supercharger on gasoline engines because of it's ability to move large volumes of air.

These engines even in naturally aspirated form however do require LOTS of clean air.
This fact is often overlooked and that's when the problems start to develop.


The 100 HP figure seems awfully low for a 671, there are no 653's only 6V53's, and even then 100 seems low.
671 naturally aspirated engines were usually rated at 238 HP and turbocharged ones were rated at about 280-285 HP. Mind you these figures are at 2100 rpm, not 1800 rpm, but still a long way from 100.
Also this figure is from the later 4 valve/cyl. engines not the 2 valve units.

Still a very nice piece especially in the shape yours is in. These engines have a long history originating in the thirties and there are still many hundreds of thousands in active service. Too bad it has what may be a bit of an albatross attached to it.

Whatever, just don't give it to Tiffie.:D

The Artful Bodger
04-04-2012, 08:43 PM
Still a very nice piece especially in the shape yours is in. These engines have a long history originating in the thirties and there are still many hundreds of thousands in active service. Too bad it has what may be a bit of an albatross attached to it.



I may be way out on the engine number as I didnt really take note of it but I do know the output is about 75KW.

I agree the generator is a bit of an albatross and I have been advocating that we lift the engine out and sell it in an unencumbered state. Unfortunately I cant imagine a serious sale of the alternator but the trolley is in very neat condition and would be ideal for displaying an Avon jet engine that we are cleaning up and might even section.

lakeside53
04-04-2012, 09:25 PM
Unfortunately I cant imagine a serious sale of the alternator


It would make one heck of generator for wind turbine - the type that just pours the current into batteries for storage.

The Artful Bodger
04-04-2012, 09:53 PM
It would make one heck of generator for wind turbine - the type that just pours the current into batteries for storage.


Not so silly as it may sound, it is fairly low voltage (120V phase - neutral) but I think it is a bit heavy for most home built wind turbines, I will see if I can find someone building a small hydro... thanks.

lakeside53
04-04-2012, 09:57 PM
If you ignore neutral, it's 208v between the phases.

Use the wind powered raw energy to heat stored water then recirculate that heat as required. Night heating of green houses come to mind.