Engine/Transmission (1994 - 1998) Ready for runaway(?)

[WBusa]

Ever since I became a diesel-head a year ago, I've been slightly paranoid about 'diesel runaway'. Just reading about this, here and elsewhere, is enough to make the hair stand up on the back of my neck. I realize its a one-in-a-million phenomenon, and can probably be avoided by taking care of your turbo, but paranoia is never trumped by mere rationality.



So, of course, I keep a dry chemical fire extinguisher in my cab, and like the instructions in the owners manual say I'm prepared to fire it into the air intake if a runaway situation ever develops. But I've never been quite satisfied with this solution, for two reasons:



1. If my aFe air filter is really doing its job, the powder shouldn't get into the engine very well at all, and



2. Even if the powder does get in and extinguishes the runaway, I'd still be left with a ruined engine from all that powder residue in the cylinders and the charge air circuit. Hey, if I'm gonna destroy my engine either way, I think I'd rather just stand back and watch the Cummins blow itself to smithereens!



I know there are other solutions, involving installing a kill valve on the intake manifold, but the odds of me ever actually doing that are low to say the least.



So... I've just bought me a Halon fire extinguisher and mounted it in the bed just in front of the tailgate. For those who don't know, Halon is a freon gas, once very popular for extinguishing fires around equipment, such as computers, that would be damaged by dry chemical fire extinguishers. It is now illegal to manufacture the Halon compound (due to that whole hole-in-the-ozone-layer thing), but there are still a lot of grandfathered Halon extinguishers out there that are perfectly legal to buy, own and use. Because Halon is a gas, not a powder, it doesn't leave any residue, and so doesn't damage the things you spray it on or into. Also, as a gas, it should suck right through the air filter. You can still buy these babies from fire extinguisher companies, but the prices are sky-high... like $250 for a relatively small extinguisher. I bought mine on E-Bay, used but freshly tested and re-certified, for about $80.



Just FYI.

 

[Forrest Nearing]

you can just set up a C02 bottle to fog the inlet of the turbo and put out the fire... no oxygen = no runaway



Forrest

 

[RustyJC]

As was said, a CO2 fire extinguisher into the intake will shut down the engine with the least amount of damage and/or cleanup.



Rusty

 

[WBusa]

you can just set up a C02 bottle to fog the inlet of the turbo and put out the fire... no oxygen = no runaway

Sure nuff, Forrest... that's the same thing the Halon does. My only concern about CO2 is that, in the presence of moisture plus heat it becomes carbonic acid, which is quite corrosive (remember the old "drop a tooth in a bottle of Coca-Cola" trick?). I'm not sure I want to flush carbonic acid through my beloved Cummins. Nitrogen would be good, since unlike CO2 its quite inert, but hauling around a bottle of liquid nitrogen is quite unworkable (whereas hauling around a bottle of liquid CO2 is easy, which is why they sell CO2 fire extinguishers). Freon is about as inert as it gets so its probably the most friendly thing you can hose into your Cummins, plus like CO2 its easy to store in the liquid state.

 

[bgilbert]

You don't have He-Man strength? In the event of a runaway you couldn't yank off the air filter intake hose or charge air pipe at the intake horn and place a clipboard, briefcase or block off wood up to it to cut off the O2? Or carry a 7/16" wrench or deep socket+ ratchet to loosen the clamps off the boots or intake hose? I know I'd give it a shot before I'd let it come apart. Course I do have a 10BC extinguisher mounted in the cab. I didn't know you could shoot it into the air filter to stop the runaway.

 

[DHayden]

I have an extinguisher also, I had a little runaway when using a starter fluid that was "approved" for Diesel use. I have to say, when that baby takes off. . it takes off quick and you have a big huge pair of brass one's if you can stand at the engine compartment during a runaway.



My hood was already open and that bad boy sounded like it was going to come apart. I have dealt with many emergency situations with my job so I stay relatively level headed... being level headed I decided I wasnt going to stand in front of my engine with the hood open :-laf



Some type of remote mount system would be ideal for you family guys, I know the young bucks with nothing else to live for than their trucks will probably give the extinguisher a try

 

[DieselTweaker]

I would recommend CO2, or a guillotine after the turbo.



and im sorry to say I wouldnt try to do anything else to a run away it's unreal what one sounds like when it desides it's going to go, A old diesel tech told me one time that he used HEEL DUST to shut them down, and you get the heel dust by running the other way.



also ive heard that a turbo will turn a phone bood into confetti

 

[WBusa]

You don't have He-Man strength? In the event of a runaway you couldn't yank off the air filter intake hose or charge air pipe at the intake horn and place a clipboard, briefcase or block off wood up to it to cut off the O2? Or carry a 7/16" wrench or deep socket+ ratchet to loosen the clamps off the boots or intake hose?

:-laf Oh, man, I think I wet myself laughing, Bill.



Hey, does anyone have any practical experience mounting a fire extinguisher in the engine compartment and permanently plumbing the end of its hose into the intake air circuit? That way you could just pull the pin, lock the handle up with a metal sleeve, and run like hell. If you've done something like this, what fittings did you use and where did you plumb in the hose? Or are summertime under-hood temperatures too high to expose an extinguisher to (heck, they can't be much higher than cab temps after parking on summer asphalt all day, and we all keep extinguishers in the cab, right?)

 

[KB0OU]

It is very common to have a valve mounted in the inlet to the turbocharger that is remotly operated to shut down a run away diesel. They are required in most oil field service trucks.

 

[VicR]

It is very common to have a valve mounted in the inlet to the turbocharger that is remotly operated to shut down a run away diesel. They are required in most oil field service trucks.

This sounds like a TDR garage enterprise just waiting to happen. Anyone? I'd probably put one on, just for peace of mind.



-Vic

 

[JohnE]

No Halon!

Halon injestion will not stop a diesel engine. The heat and pressure in the combustion process will actually break down the Halon and keep on running. The tailpipe spews a very toxic product know as Phosgene gas. Phosgene was used in WWI on soldiers in trench warfare as nerve gas.



I'd stick with the dry chemical or CO2. BTW, if your airfilter won't stop the engine damaging parts of a dry chemical (ammonium phosphate) unit that means it passes the same particles in daily usage.



-John

 

[TheodoreMoon]

Will the dry powder stop the runaway by entering the chamber to stop combustion or just by clogging up the airfilter mechanically and preventing intake?

 

[RDupree]

i had a dt466 runaway on a cold rainy day,i pulled my raincoat off and stuffed it into the air filter inlet,it slowed down but did not shut down!i unscrewed the fuel line going into the filters and just before it shut down it blew the clutch out. . i was scared shirtless! saved the engine though.

 

[WBusa]

Will the dry powder stop the runaway by entering the chamber to stop combustion or just by clogging up the airfilter mechanically and preventing intake?

Theo, I think it may be "six of one, half-dozen of the other". I'm guessing (but only that) that Dodge's recommendation assumes that the stock filter isn't very efficient, and thus will let the powder through. Actually, I think you would hope it wouldn't clog the filter... since the humongous vacuum the runaway engine is trying to create would prolly just rip your clogged filter to shreds, suck in all that debris, and keep runnin'.



By the way, I just read the ingredients on my dry-chemical ABC extinguisher. "Crystalline silica, ammonium phosphate and ammonium sulphate. " I'm thinkin' that crystalline silica (for all practical purposes, rock dust; I assume its there to keep the chemical powders free-flowing) isn't going to do red-hot cylinders and pistons any good a'tall!

Halon injestion will not stop a diesel engine. The heat and pressure in the combustion process will actually break down the Halon and keep on running. The tailpipe spews a very toxic product know as Phosgene gas.

John, I'm not questioning your facts but... well, maybe I am; I don't know. I realize that Freon 12 (the old-style refrigerant gas) will, when passed through an electric arc (i. e. , thousands of degrees Farenheit) break down into phosgene gas (fire, as opposed to an arc, isn't hot enough to do this). But yours is the first assertion I've heard that this is also true for Halon (a different chlorofluorocarbon than Freon 12). Its kind-of hard to imagine that Halon would have become such a popular fire extinguishing chemical if it readily formed a toxic gas when heated... . I'm not trying to pick a fight here, I'm just puzzled. Can you tell me where you got your info, especially the assertion that it "will not stop a diesel engine"? It seems to me that any non-combustible gas that displaces air will put out a fire. If I'm wrong about Halon I'd sure welcome being persuaded.

 

[WBusa]

Hmm... maybe I need to stand corrected regarding the hazards of Halon 1211. I just did a quick query at the NIOSH (National Institute of Occupational Safety and Health) web site, and found this statement: "The substance decomposes on contact with open flames or very hot surfaces, producing toxic gases including phosgene, hydrogen fluoride, hydrogen chloride, hydrogen bromide. " Some other sites I looked at said that the amount of phosgene produced by Halon 1211 is minimal, but large amounts of hydrogen fluoride (HF) are produced. Actually, that concerns me more than phosgene does, since HF is just about the most aggresive acid known to man. It will eat right through glass, steel, and many other substances (the only two substances it won't eat, that I know of, are Teflon and wax). It will also turn your lungs to jello on contact. Hmmm... . maybe CO2 is the way to go, after all.

 

[JohnE]

... Can you tell me where you got your info, especially the assertion that it "will not stop a diesel engine"? ...

USCG Boating Safety Class 1992

Enough air gets slurped in with the Halon that is keeps the engine running and producing Phosgene. The temps & pressure involved in combustion makes it possible.



The computer industry used Halon systems very heavy until they discovered that little problem with Hydrogen Fluoride. The Halon recyclers make quite a business on old computer rooms. They reclaim and sell it to the places that still use Halon such as marine.

Yes, marine. most marine systems have shutters on the intake to choke a runaway and prevent ingestion.



CO2 ? Can I stir the pot? Not effective for aluminum, magnesium, and titanium fires. Again, the heat produced breaks down the CO2 and keeps on a burning.



-John

 

[RustyJC]

CO2 ? Can I stir the pot? Not effective for aluminum, magnesium, and titanium fires. Again, the heat produced breaks down the CO2 and keeps on a burning.

So, how is this relevant to shutting down a runaway diesel engine using CO2?



Rusty

 

[Ol'TrailDog]

It is very common to have a valve mounted in the inlet to the turbocharger that is remotly operated to shut down a run away diesel. They are required in most oil field service trucks.

Perhaps, someone could expand on KB0OU's statement. Seems like this could be a feasible way to go, since it is already in use.

 

[WBusa]

Perhaps, someone could expand on KB0OU's statement. Seems like this could be a feasible way to go, since it is already in use.

http://www.rodadeaco.com/sitepage/mainjs.htm - a Canadian company that manufactures air intake shutoff valves for diesels. Not a bloody lot of info on their web site, however.

 

[Joe G.]

Just a little reality check here. I don't recall any post on any of the TDR forums that reported a B5. 9 Cummins run away. Does anyone know of this happening in a Dodge? In anything else that runs one of these B5. 9 engines?