Runaway Multifuel cutoff?

[army70deuce]

I've just purchased my first 1970 AM General Deuce, YEA!!!! Here's the question:

I've been around a run away marine diesel before and its somewhat scary, has anyone ever heard of a runaway multi-fuel and has anyone ever considered installing a large valve on the air intake that can be operated from the cab in case of a run away? My experience is that just cutting off the fuel isn't enough because the engine could still burn the crank case oil and keep going til you blow the engine, so plugging (or in this case closing) the intake is the most dependable way of saving your engine. Any and all input is appreciated, Thanks.

 

[SCSG-G4]

There are several threads on just that subject - actual run away engines - but very few have rigged up anything except a large piece of wood and a CO2 fire extinguisher (pull the mushroom off and either cover it with the wood or goose it with the CO2. A masonite clipboard was used once - but failed when the suction ripped a hole through it.

BTW, where in SC are you?

 

[avengeusa]

i have been wondering the same thing also

 

[Chevytruck]

i have been wondering the same thing also

ME too!

 

[army70deuce]

I've been thinking that if a butterfly valve was installed between the mushroom and the air filter or between the air filter and the intake, you could hook up a simple pull cable to close the intake off and not waste time getting out of the cab. Simply run the pull cable through the firewall and put a pull tab on the dash "Emergency Shut Off" that way anyone nearby could use it with no explanation necessary. Should be a pretty simple build just need to find the right sized butterfly valve.

 

[mudguppy]

what's the concern - has a multi ever run away? detroits are notorious for having their racks stick and cause a runaway, for example. but is it even possible for a multi to runaway on fuel only?

the only thing i can think of is an oil seal failure on the compressor side allowing oil to come in through the intake. regardless, i think this would be more paranoia than potential.

 

[Recovry4x4]

There have been reports of IP malfunctions that were not known at startup. This was mostly on trucks that sat for quite some time and the fuel shutoff was frozen, result? Runaway. Any time I start an unknown multifuel up, I have a small piece of 3/4 plywood to plug the intake. I'm not aware of anything causing a runaway while going down the road. I do have personal knowledge of the IP issue runaway, happened to Ronzo Johansen in New England.

 

[wreckerman893]

Me and Freightrain cranked a multi that had been sitting a while and it went wide open...it shut down with the fuel shut off.

I had a 250 Cummins in my 816 that ran away due to fuel in the crankcase.....I stuffed a towel in the air intake and killed it. It would not shut off with the fuel shut off.
Managed to keep it from going high order but it damaged some valves.

Cutting the air is the best way to kill a runaway diesel but you have to have a tight seal.

 

[wdbtchr]

I've seen signs posted on the steering wheel at GSA auctions warning not to start the engine because it would run away. Blown turbo seals is one way this could happen. I've never seen one in person, but Grove cranes have an air shutoff on the inlet to provide emergency shutdown. I saw one attempt to start a Grove model 70 with the valve tripped, done by a vandal. Never saw so much black smoke but the engine barely ran.

 

[drgreg]

Craftsman 4 in. Blast Gate, Aluminum

A 4in. blast gate may be an easy install and it would cost about $20 for all the parts.

 

[tjcouch]

Somewhat related - my engine was not burning the crankcase oil, but was a throttle linkage issue:

http://www.steelsoldiers.com/deuce/9988-check-throttle-linkage-folks.html

A Detroit mechanic told me of an engine that ran away in the shop. They tried to stare it with a phonebook - it ingested the book, blew it out the stand AND THEN blew up.

An old Army driver told me he was instructed to shove his BDU jacket into the intake to kill it . . . he also spoke of something called a "chicken block" - a large cupped piece of wooden block that was milled to fit over the intake.

I always wondered if dumping the clutch in 5th with the brakes locked would stall the engine . . . .

 

[Kennay]

I always wondered if dumping the clutch in 5th with the brakes locked would stall the engine . . . .

You just nailed it. You really only need to worry about runaways if you have an auto. Brakes + one of the taller gears = it's going to die, especially if you are at a dead stop. Period.

 

[drgreg]

You just nailed it. You really only need to worry about runaways if you have an auto. Brakes + one of the taller gears = it's going to die, especially if you are at a dead stop. Period.

I would think that something would die. The engine, the drive line, the engine and drive line. Please report back how well this works for you.

 

[swbradley1]

That was my first thought. Runaway engine and then popping the clutch in 5th.

Ahhh good times.

 

[atankersdad]

My sons recovered a winch truck at Meade 2 weeks ago. It ran away when started. Luckily, they pulled the cap and smothered it before it blew. Anyone want to buy a winch truck??? It gives a new meaning to reading "starts and runs"....

 

[m-35tom]

as long as you can pull the fuel shut off, you can kill it. just see that the shut off operates before you crank it. as to the clutch in 5th gear, once the engine is past 8000 rpm i doubt it would stop it...............

 

[dittle]

We started a M35A2 with whistler turbo at the museum about 1-1/2 years ago and the fuel shut off was stuck on the IP -- hence runaway at 1200 rpms. We pulled the mushroom off of the truck and stuck a board up against the intake at the air cleaner. All it did was made the turbo whine increase in intensity, but didn't show down the engine at all. Ended up having to take the tube off right against the turbo and put a board against the side of the turbo -- shut it right off.

My uncle was a M109A3 mechanic during Desert Storm and was telling me about once when they were ground hopping a pack for 109 before re-installing it. The engine had a runaway and a Sgt. was walking around with a TM for the vehicle so he walked over to the turbo to kill the runaway. Needless to say that engine was strong enough that it sucked the entire TM in through the turbo and ruined the engine.

 

[FreightTrain]

I had a near miss with a true runaway last year.I had a turbo blow.Luckly it dumped oil into the exhaust instead of the intake.Seen one run backwards at last year clinto rally too.That was interesting.....1 forward gear and 5 reverse with smoke comming out the mushroom......

 

[dittle]

I've heard of a multi running backwards once. Forget how it got started that way but it was a very interesting story.

 

[littlebob]

as long as you can pull the fuel shut off, you can kill it. just see that the shut off operates before you crank it. as to the clutch in 5th gear, once the engine is past 8000 rpm i doubt it would stop it...............

Not if you lose a turbo seal on the intake side. It will pull the crankase oil into the intake and use it as fuel.