Runaway multifuel 6/20/14

[roscoe]

And since you didn't get hurt take a moment to just laugh about this - think of how terrifying it was to have that big beast of a diesel engine out of your control in such proximity to you. That real butterfly in the stomach feeling is hard to replicate with movies (I'll bet you had adrenaline shakes for a few minutes afterwards).

I agree there must've been another air source - if you could put the block of wood on and then take it off by hand while the engine was revving, there was another way in for the air. Of DD nV53, nV71, and nV92 engines, a common cause of runaway was engine oil getting in the intake from the turbo (bad seal), or the roots-blower (another bad seal). Diesel's are a lean burn engine, so any source of fuel will make the fire burn hotter and the engine want to spin harder - of course having a disconnected governor or a maladjusted fuel rack or injector stuck open (fuel contamination or collapse of fuel filter) will have similar effect. Using too much d@ng starting fluid will do it too:

Just remember, don't panic! Try to close it off and back away lest you get burned

It sucked the 6x6 block to the intake hole and held it there. The multifuel runaway was way more intense than this video. The smoke was coal black, pouring out of the stack like an old freight train. Definitely intense.

 

[roscoe]

Well you'll get to know your truck intimately when you change the engine. Post pics of the autopsy.

I thought I knew her pretty intimately already, but she showed me a whole new crazy and scary side.

 

[roscoe]

Sorry to hear this. There is many things that can go wrong when you start a motor, this time it must not have been meant to be! You try to be prepared but its hard to cover EVERYTHING.


Sorry for your loss.

Thanks, it sucks, but nothing to do now but asses the damage and move on. Maybe the next person will get some helpful insight as to what to do and not to do.

 

[roscoe]

Look at the bright side. Worst case, another engine. It did not grenade, you are not full of metal, and there are no shrapnel holes in the hood or body.
Future tests, before starting engine, consider blocking off the fording port on the air cleaner.

t
You can bet that fording hole will no longer be a hole. It was heartbreaking to hear the engine revving into the stratosphere, but with all the black smoke and remembering a line in the TM that said something like "run for cover", I did have personal safety in the forefront on my mind.

 

[todds112]

Went out can checked the fording hole on mine. I'll be plugging that asap, just in case.

 

[Valence]

The moral of the story is it might not be a bad idea to have a CO2 extinguisher on board and handy at all times. Air leaks or no air leaks, a quick shot of that into the intake will shut it down no matter how it is running away.

Would a Halon fire extinguisher work for this, or would that chemical be bad for the engine? I have one of those with a larger regular ABC

 

[Pugsley]

I don't think the Halon would be bad for the truck, but if you are in an enclosed space it WILL be bad for you.

 

[Ferroequinologist]

Powdered or liquid extinguishers are a no no. Severe engine damage would result. Any inert gas introduced in volume into the intake will kill the engine.

 

[mbehne]

t
You can bet that fording hole will no longer be a hole. It was heartbreaking to hear the engine revving into the stratosphere, but with all the black smoke and remembering a line in the TM that said something like "run for cover", I did have personal safety in the forefront on my mind.

Keep your fingers crossed! I had one do this, same smoke, same intensity ect but I think soldier b reacted quickly enough to keep her below critical mass and she still lives and breathes. I'm not sure where mine was pulling air as I had soldier b standing by just in case, mushroom and air filter removed so no fording hole was involved, flat block and heavy shop rug(way to big and heavy to be sucked in) to stuff directly to the intake hole. The block would slow it down but not kill it...I don't think black smoke describes it well enough! I know if I saw that rolling out of any building 911 would get the call!

btw....CO2 extinguisher close by now!

 

[FMJ]

When you replaced the HH did you install new O-rings top and bottom? Bad O-rings will allow fuel into the crankcase.

 

[Reaper651]

About the CO2 or Halon fire extinguisher. I know the CO2 one would work and I believe a Halon would work equally as well. Since reading this thread, I have been looking into the air valve style emergency shutdown systems. They look great but all are quite expensive. The other issue I can see is the only way to mount one on a Deuce would be pre turbo. If the turbo seal is bad and/or there is an air leak on the turbo, the valve wouldn't shut it down. I think the CO2 fire extinguisher would be best, it will shut it down no matter what. Has anyone actually used a CO2 extinguisher to shut down a runaway multifuel? I have also been thinking of a way to integrate a CO2 shutdown system using a custom built CO2 system made from a onboard fire system like the ones race cars use. Install the system and install a single nozzle somewhere in the intake system. If it runs away, hit the fire bottle button and she shuts down. I think this would work well and be cheaper than one of the emergency shutdown "Air valve" systems. I would also have a CO2 extinguisher on the truck just incase the fire system malfunctioned.

To the OP, I'm sorry this happened. Hopefully your engine is still in working condition.

 

[rustystud]

About the CO2 or Halon fire extinguisher. I know the CO2 one would work and I believe a Halon would work equally as well. Since reading this thread, I have been looking into the air valve style emergency shutdown systems. They look great but all are quite expensive. The other issue I can see is the only way to mount one on a Deuce would be pre turbo. If the turbo seal is bad and/or there is an air leak on the turbo, the valve wouldn't shut it down. I think the CO2 fire extinguisher would be best, it will shut it down no matter what. Has anyone actually used a CO2 extinguisher to shut down a runaway multifuel? I have also been thinking of a way to integrate a CO2 shutdown system using a custom built CO2 system made from a onboard fire system like the ones race cars use. Install the system and install a single nozzle somewhere in the intake system. If it runs away, hit the fire bottle button and she shuts down. I think this would work well and be cheaper than one of the emergency shutdown "Air valve" systems. I would also have a CO2 extinguisher on the truck just incase the fire system malfunctioned.

To the OP, I'm sorry this happened. Hopefully your engine is still in working condition.

I think that is a good idea you have there Reaper, using a CO2 extinguisher with an emergency kill switch. That could be a Life (engine) saver !

 

[RAYZER]

I think that is a good idea you have there Reaper, using a CO2 extinguisher with an emergency kill switch. That could be a Life (engine) saver !

I like this idea also, what size extinguisher would be sufficient for this application?

 

[Keith_J]

What is the smallest CO2 cylinder you can get? Not a 12 gram, that would not be enough. 5 pounds would be plenty.

 

[RAYZER]

A friend of mine fashioned a quick discount for the mushroom making it easy to gain access to opening the side panel, then put an easy access square of plywood on the back of the side panel.
I thought this was a quick way to kill the air.

 

[Recovry4x4]

Argon would work too but it would take quite a huff to get it in there. CO2 definitly would be the easiest way to combat this. When I do ground hops I have a piece of plywood on the ready to block off air right at the turbo. FWIW I ground hop every engine I install.

 

[doghead]

Perhaps practicing an emergency shutdown would help some gain comfort from this concern.

Adding an air butterfly shutoff would be a nice modification, if your worried about run aways. (mandatory in some sanctioned events for diesel powered trucks and tractors).

 

[gimpyrobb]

If someone were to want a butterfly valve for their intake, I just happen to have some! They are mil-spec too, nsn: 4820013264512. PM for info.

 

[gimpyrobb]

I've had more than a couple folks ask about the valves. I will post up a classified later today. Going for a GL loadout.

http://www.steelsoldiers.com/showthread.php?125970-Butterfly-valves&p=1565951#post1565951

 

[roscoe]

When you replaced the HH did you install new O-rings top and bottom? Bad O-rings will allow fuel into the crankcase.

I got new o-rings first, thinking that was my fuel leaking issue. I put those 3 on and it still had fuel leaking and I saw another thread where those HD are prone to crack and all the symptoms were the same as mine, so I got a NOS head and put my new o-rings on it. I think my runaway problem is related to my reassembly of the throttle shutoff linkage.