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View Full Version : Dyno-testing disasters car tuning gone wrong



wierdscience
05-17-2012, 10:32 PM
Oh theh humanitah:D

http://www.youtube.com/watch?v=OzFGUUR1UDI&feature=endscreen&NR=1

justanengineer
05-17-2012, 11:02 PM
Thanks for posting. Hopefully some of these videos will keep those with little experience/intelligence from tempting fate being near a spinning dyno.

Quite often I have to help our test engineers run the dyno/instrumentation to test the engines I design for a living. I used to love being in the cell itself while things were running, until a few digital safety measures failed, the engine I was working on oversped, several pistons contacted injectors and "ejected" them at me in <3 seconds. Luckily I was unhurt (missed) but the lesson stuck and I hide in the control room unless absolutely necessary now.

dian
05-18-2012, 04:56 AM
i always wondered why in the states you use the type of dynos as pictured. i never acually saw one like that. here we have the ones with two rollers, they automatcally allign the car, no need to strap it down. are they much more expensive?

Doc Nickel
05-18-2012, 05:47 AM
Single rollers allow a larger roller, which in turn means a better (larger) contact patch to the tire.

And *all* chassis dynos, including twin-roller, require the car to be strapped down. Not just for safety, but the idea is that it's a dynamometer- there's a brake acting against the roller(s)- they're not just free spinning- so without some form of restraint, the car can- and will- roll away.

A low-powered car might get away with a parking brake or wheel chocks, but any kind of powerful or modified car *must* have restraints.

Doc.

vpt
05-18-2012, 08:15 AM
Thanks for posting. Hopefully some of these videos will keep those with little experience/intelligence from tempting fate being near a spinning dyno.

Quite often I have to help our test engineers run the dyno/instrumentation to test the engines I design for a living. I used to love being in the cell itself while things were running, until a few digital safety measures failed, the engine I was working on oversped, several pistons contacted injectors and "ejected" them at me in <3 seconds. Luckily I was unhurt (missed) but the lesson stuck and I hide in the control room unless absolutely necessary now.


Yeah I always cringe when I see people standing close to a car running on the dyno or those guys that feel the need to stand over the motor while pulling.

I've heard plenty of stories of parts getting stuck in the lexan windows of dyno rooms.

Some of these videos also show the dyno owner themselves doing some of the dumbest things. No straps, straps to the rear door latches (LOL) its sad.

wierdscience
05-18-2012, 08:45 AM
My brother worked for an IH truck dealership right about the time they became Navastar.One of their mechanics was running up a Freightliner conventional on the dyno,he had put the safety chain on the rear cross member,but forgot the frame chains.

The tires glazed over and then broke down and hooked up causing it to hop a couple times at which point it straightened out the hook on the safety and the truck left the building,literally.It went out through the parking lot,through the fence,across a ditch,into the parking lot of the supermarket next door and started wadding up cars in front of it.The side of the supermarket building finally stopped it.Luckily nobody was hurt,but the damage was impressive.

The mechanic just loaded his tools up and ten minutes later was never seen again.

vpt
05-18-2012, 08:48 AM
^ were the brakes not working?

wierdscience
05-18-2012, 09:11 AM
^ were the brakes not working?

Nobody in the cab,he got bucked out the door when it hopped.Truck only went a few hundred feet,still managed about six totaled cars and some busted blocks in the side of the supermarket.Lots of mass spun up in a truck doing 70mph.

Willy
05-18-2012, 11:03 AM
Thanks for posting. Hopefully some of these videos will keep those with little experience/intelligence from tempting fate being near a spinning dyno.

Quite often I have to help our test engineers run the dyno/instrumentation to test the engines I design for a living. I used to love being in the cell itself while things were running, until a few digital safety measures failed, the engine I was working on oversped, several pistons contacted injectors and "ejected" them at me in <3 seconds. Luckily I was unhurt (missed) but the lesson stuck and I hide in the control room unless absolutely necessary now.

I was in a dyno cell years ago and experienced the same thing and could not agree more!
Lots of dirty laundry for me that day.;)
When the sh*t hits the fan you can't run fast or far enough!!

Here's a classic example of what it's like when a large V-8 diesel grenades under load.

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

MrFluffy
05-18-2012, 11:07 AM
I had one of my bikes on the dyno and they strapped down with really pathetic luggage straps. Happily all it did was snap the straps and spin the tyre on the roller when the boost came in. Ditto for when they repeated with a guy on the pillion.
Then they committed the cardinal sin of turning it off at high rpm after the run instead of letting the heat come out the hot turbo first and gave me a ticket claiming it had 92hp and charged me for the privilege as "the run was good". I was suffering wheelspin at 120mph in the dry and was running 16psi of boost with it in a 750cc engine, and they told me I had 92hp with a straight face.

I'm in the planning stages of building my own in my barn after that experience to set my dragbike up on. I have a oldie but good 750Kw (1000hp) heenan and froud dpy water brake, and a drum and drum shaft setup from a road roller so far. Guess I better plan in some remote means to control the subject under power too, in addition to the extractors and soundproofing!

dian
05-18-2012, 12:33 PM
well, i havent seen a car strapped down on the dyno yet. when i was installing motecs, i just drove onto the dyno, got the ticket and drove off to do some more tuning. obviously two rollers have more contact than one. we also dont mess with engine hp and hp at the wheel we have din (en) hp and its clear what it is.

Orrin
05-18-2012, 08:36 PM
Is anybody able to tell me why a video camera was "conveniently" running in each one of these events. To me, it seems as though someone with too much time and money was deliberately trying to collect on their warranties.

Orrin

sasquatch
05-18-2012, 08:51 PM
Seemed to me anyway,, there were too many guys wandering around some of those videos, no wonder people get hurt,, like the guy that tripped , fell flat on his face,, man,, that must have broke his nose!!:D

justanengineer
05-18-2012, 10:32 PM
Is anybody able to tell me why a video camera was "conveniently" running in each one of these events. To me, it seems as though someone with too much time and money was deliberately trying to collect on their warranties.


In better test cells, the operators/test engineers monitor the engine visually via video cameras in addition to using other instrumentation and the shatterproof window.

In a "for hire" shop with a dyno installed in an open bay, I would suspect making it an "event" is half the draw. Even amongst serious auto hobbyists, most tend not to pay for dyno time with any regularity, so video cameras are to be expected. The same thing applies to power numbers that are bigger than the engine, theyre good for business.

Willy
05-18-2012, 11:27 PM
In better test cells, the operators/test engineers monitor the engine visually via video cameras in addition to using other instrumentation and the shatterproof window.

In a "for hire" shop with a dyno installed in an open bay, I would suspect making it an "event" is half the draw. Even amongst serious auto hobbyists, most tend not to pay for dyno time with any regularity, so video cameras are to be expected. The same thing applies to power numbers that are bigger than the engine, theyre good for business.

Ditto.

Plus like justanengineer said it is indeed an event.
Buddy has just spent $2,000-$40,000 dollars for more ponies and he wants the footage captured for posterity of the car/motor actually pulling the big number.
Between the cubic dollars invested into the power-train and the dyno time, yeah it's a special moment that most would like a record of.

Accidents are preventable by strict adherence to safety guidelines. Most of the mishaps shown are the results of dyno operators not following safe operational procedures.

Engine blowups. Well that's racin.;)

For those that play in this very expensive arena there are no warranties, just pick up the pieces and learn from your mistakes. As you can see the learning curve can be a steep one.

wierdscience
05-18-2012, 11:53 PM
Yep,and how else would we get to see stuff like this?:D

http://youtu.be/d_8Fc9qAZcw

lakeside53
05-19-2012, 01:57 AM
yikes...... expensive, but cool though:D

aboard_epsilon
05-19-2012, 06:42 AM
i dont know whats what in the last video ..but you do see the large silver pipe at the top of the engine grow in diameter a couple of seconds before it blows its head off.

all the best.markj

philbur
05-19-2012, 06:51 AM
I don't think he tripped, he put one foot on the rolling road and it whipped it from under him.

Phil:)


Seemed to me anyway,, there were too many guys wandering around some of those videos, no wonder people get hurt,, like the guy that tripped , fell flat on his face,, man,, that must have broke his nose!!:D

vpt
05-19-2012, 08:28 AM
Lots of these video taped dyno deals are "dyno days" that is also why there are 100 people standing around. Dyno days for those that don't know are days where a group of people go to a dyno house and get 3 or so pulls each. Usually about 12 cars fill up the day.

Last time I was at the dyno, behind the lexan, with a video camera. :D FIY on the video, the guy didn't know the redline on the factory tach wasn't the actual redline for the motor. It was just getting wound up when the guy let off... Still got 240hp on the graph though!

http://www.youtube.com/watch?v=nDO8qTR-1sg&list=UUjGabqSas3YXEXyT-AmpRNw&index=2&feature=plcp

John Stevenson
05-19-2012, 04:19 PM
Not vehicle dyno but engine dyno related.

As an apprentice we had to do two weeks in the engine test house.
This was on Rolls Royce 6 cylinder and 8 cylinder engines as fitted it armoured cars and the like.
We also had to test the detuned RR Merlin engine called the Meteor.

Originally a long building, 12 bays long, with a dyno in each bay and the guys would sit at the side of the engine with ear muffs on during testing.

At some time previous to my time there the last two bays were enclosed to make a soundproof test cell with the other to follow on [ never did ]
This is the cell apprentices were sent to, one room with all the controls and instruments and the end cell with the engine in.

Engines were craned into place, connected up and started, no radiators, water came from a header tank on the roof and no exhausts, just the flange face on the heads.

Initially they ran 1/4 throttle for one hours and checked for leaks etc then half throttle for 1/2 hour.
After this time tuning was started.

First thing was mixture was set at 1/2 throttle. This entailed lyling full length over the engine with a long screwdriver and a ring spanner welded to another long screwdriver for the lock nuts.
Mixture was set for 6" of blue flame out of the exhaust.
The noise was awesome but as you were laid across the engine your apprentice master would rev the engine up and only the liars never admitted to shėtting themselves :D

You couldn't do the same to them as they were used to it, they just leaned over and pushed the throttle closed.

Next check was timing.
These were pretty much dead on as the line were used to building these. We had all the books but the guys knew all the wrinkles and what worked and what didn't.
Timing check was take the engine flat out to 2,400 revs, kill one magneto and it should drop 200 revs, if it didn't drop 200 revs the working mag was too far advanced, more and it was retarted so you pulled the mag and adjusted the vernier coupling one or two notches and tried again.

Once that mag was OK you did the second mag.

One day I had disappeared for a walk round as engine testing was real boring. When I came back my apprentice master was doing mixture setting lying over the engine. Knowing it was a waste of time revving it up I crept into the booth on my hand and knees so he wouldn't see me thru the window and hit one of the mag kill switches, engine note changed but I kept my head down. Then I hit the other kill switch and dared a peak just in time to see him pumping the throttle arm to try and keep it running.

After 6 or 7 pumps which must have translated to about 3/4 a gallon of petrol I released both mag switches.

Colour me impressed with the backfire :D
The rest of the testers and myself were dead impressed but somehow my guy wasn't ?? :confused:

However to get back to the OP it's a bit scary having 17 to 19 year olds laying over 27 litre V12's running flat out but no thought was given to it back then.

Carld
05-19-2012, 04:54 PM
Only one roller on twin roller dynos are connected to the torque converter. The other roller is an idler.

I worked in a Cummins factory distributor and one time a mechanic was chassis dyno testing an NT350 at 350 hp full load, full rpm and the restraining chain broke. The truck went 50' across the drive before he could stop it.

Needless to say it scared the hell out of him.

Another time a mechanic was engine dynoing an NH250 natural aspirated Cummins and it started running wild. The first thing he did was lay his shop manual over the intake port and it sucked the manual into the engine and finally stopped the engine. We found parts of the manual everywhere in the combustion chambers.

We never did figure out what caused it to run away as Cummins engines don't do that but Detroit's sure did.

Clevelander
05-19-2012, 10:25 PM
Does this void my warranty? ;)

Carld
05-20-2012, 12:26 AM
Warranty, you want warranty, we got guns and bullets, you got no warranty :D

willmac
05-20-2012, 10:48 AM
A long time ago I worked at a factory that had been a 'shadow factory' in war time. It produced Bristol Hercules engines at the rate of about 2/hour, which is not bad for a complex engine. At the far end of the factory was an ugly concrete building, which apparently was the test house for the engines, in which they would be run up and tuned in the same way that John S describes. The legend was that this building was fitted with a steeple at one end to make it look vaguely like a church and therefore less likely to be bombed. When I worked there, it was used as a sort of R&D workshop. The building was impressive because of the extreme thickness of its walls. I asked the reason for this, thinking it might have been to bomb proof it, but was told it was actually to contain engines bits when they blew up, which happened occasionally. Certainly it had large chunks missing from the walls in places internally. A 39 litre 1500 hp radial engine would make a bit of a mess if it let go.

John Stevenson
05-20-2012, 11:00 AM
One thing I have remembered is that on the walls round the engines were army green fire extinguishers was well as standard red ones.

The red ones were genuine fire extinguishers but the green ones were the older twist and pump extinguishers that used to contain Carbon Tetrachloride but these had been filled with petrol so after a run the engine was sprayed down to clean up any small leaks. :eek:

Kenny G
05-20-2012, 01:18 PM
Yes, the days before Health & Safety yellow vest PPE brigade got involved. I think it was called common sense! Off course, everyone would know that the green extinguishers were full of fuel?

This was one I built this year on the dyno. Pontiac 400 with a stroker crank and Kauffman MR1 block, steel crank, Blah, Blah, Blah!

https://lh3.googleusercontent.com/-9-q9BaBEOkE/T7kj6JehDKI/AAAAAAAAAeE/LVTKEJfN-tQ/s720/Pontiac%2520461%2520Dyno3.jpg

RandyZ
05-21-2012, 12:17 PM
Colour me impressed with the backfire :D


You Sir, are pure evil. I like it!

Bill736
05-21-2012, 09:51 PM
Back in the 1970s and early 1980s, I tested a lot of cars on Clayton twin roll dynos , running the Federal Test procedure for exhaust emissions and fuel economy. The dynos had a water brake power absorber, plus flywheel inertia weights. We used a driving cycle called the LA-4 cycle ( "city") , plus a "highway" driving cycle. Rear wheel drive cars were relatively well behaved on the dyno, but front wheel cars were a bit more " squirrelly' , since any slight steering input from the driver would cause the front end to move back and forth on the dyno rolls. We had to tie them down more securely than rear wheel cars. Neither driving cycle was intended to measure maximum horsepower, so it was relatively tame , with no engines coming unglued. Only one part of the LA-4 ( city) driving cycle called for rapid acceleration, which simulated entering an interstate from an entrance ramp. Some slower vehicles couldn't keep up with the prescribed acceleration . What did come unglued occasionally, however, were tires. Dyno rolls, whether large single rolls or smaller twin rolls, can be very hard on tires. Although we always pumped the tire pressure up to 40 or 45 psi, extended dyno runs would cause tire damage that would often only show up hundreds or even a couple of thousand miles later in street use, when chunks of tread rubber would start separating from the carcass.

sasquatch
05-22-2012, 09:06 AM
kennyG , What a beautifully constructed set of headers.!

(what type of race vehichle is the engine going in?)

Kenny G
05-22-2012, 04:30 PM
kennyG , What a beautifully constructed set of headers.!

The headers caused some serious problems. Stainless Steel all tig welded and built in sections held together with springs. This allows for fitting which is a pure bxxxxxd!
They were designed to fit the Pontiac 461 stroker engine mounted on a front motor plate and snaking their way round suspension & steering components in a 1972 Vauxhall Ventora that originally had a 3.3litre, 200cu.in. 120hp straight 6 as its power!
(what type of race vehichle is the engine going in?)

The car is an early UK Street / Strip set up that ran a 396 BBC with good success. The current owner is a Pontiac afficianado. :eek: All from the GM Stable!!

https://lh3.googleusercontent.com/-nT57TQH9URs/T7vqiRyS1SI/AAAAAAAAAeQ/D49UZS8qv4I/s640/cameracard6258.jpg

https://lh6.googleusercontent.com/-j2WUcnTxh8U/T7vqwb_1H3I/AAAAAAAAAeY/LvT1XTOBl4I/s640/cameracard6253.jpg

https://lh5.googleusercontent.com/-LD1aHehiANs/T7kkYCmfujI/AAAAAAAAAeE/Ag7XZlkHU1w/s720/Pontiac%2520461%2520Dyno2.jpg

sasquatch
05-22-2012, 06:25 PM
KennyG thanks for the interesting pics!! (Nice to see set ups from abroad!!)