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

[Forrest Nearing]

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



Rusty

that's what I'm thinkin'... we're not trying to put out an aluminum fire, we're putting out a diesel fire burning at about 900-1000*



Forrest

 

[WBusa]

that's what I'm thinkin'... we're not trying to put out an aluminum fire, we're putting out a diesel fire burning at about 900-1000*

Forrest

I'm with you, Forrest. I'm thinking that if your aluminum is on fire, you really should just run away :-laf

 

[JohnE]

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



Rusty

It isn't, but partially it is.



It is very hard to starve or flood out a diesel engine. Gasoline engines will stall very quickly with either excess fuel or choking off the air supply. Also the butterly valve and spark supply controls help, too.



The examply from Boating Safety wasn't for stopping a runaway diesel. It was using a Halon extinguisher to put out a fire in the vicinty of the diesel intake and the resulting toxic exhaust.



I guess my point was a dry chemical is a better all around choice to carry in your vehicle.



If the fire gets hot enough to melt the aluminum components I hope you saved the cooler and are drowning your sorrows somewhere upwind.



If you worry about a run away diesel, get an air valve

 

[Andy Redmond]

Yes a former member of the Dallas TDR had a 96 12v truck with an 887 pump run away. Back in 1999, when the gov. spring kits first came out, he decided that they cost to much and made his own and did some other outlaw mods to the governor. Usually he could tap the throttle a few times to let the governor find itself, but one night in traffic it didn't and ran away. He also had a homemade cold air intake and stuffed his leather jacket into the intake and slowed it down enough to loosen a fuel line and let it suck air.



That was his story anyhow. I did seem some bearing damage. He polished the crank and replaced the bearings, removed the pump and had a pump shop replace the gov. parts he had messed with. .



That's the only one I know of. . I've heard rumor of a few that sucked oil from the turbo and ran away.



Have not personally documented it though.



My vote would be for the guilotine to chop the air as necessary.

 

[AMink]

Check this thread from the competition forum:

https://www.turbodieselregister.com/forums/showthread.php?t=125594&highlight=air+shutoff

 

[bodacious]

with 5 or 6 speeds what would be wrong with putting in gear then letting the clutch out to kill engine.

 

[WBusa]

with 5 or 6 speeds what would be wrong with putting in gear then letting the clutch out to kill engine.

In fact, in many of the hair-raising runaway stories I've read that's exactly how folks did manage to shut 'er down... . that, plus setting the e-brake and standing on the service brakes. But bear in mind that:



1. Our CTDs produce humongous torque, so this is by no means a sure thing. Remember, that engine is screaming at maybe 4000 RPM while you're trying to do this.

2. This option is not available to folks with auto trannies, or manuals with slipping clutches.

3. Runaway doesn't just happen when you're parked. You might be bombing down the road when it strikes.

 

[TurboTweaker]

the 5. 9 was put in a case 2096 farm tractor in the 80's and i have seen one run away. not a pretty sight or sound. with my background of pulling i'd put in a guillotine right on the intake horn. JohnE why does it not surprise me that you know these things, must suck being a rocket scientist.



The Fat Kid

Andy

 

[RustyJC]

Our company's industrial diesel & dual fuel engines have had overspeed governor-actuated butterfly valves in the intake manifolds for over 60 years.



Rusty

 

[Riddick]

Diesel Runaway

As far as I know there are 2 types of diesel runaway. One is a turbo runaway that can be caused by seal leakage causing a fuel source to enter the hot side of the turbo that causes the turbo to become similar to a jet engine. The only limit to how fast it will turn is how much fuel it gets. If it gets enough fuel it will disintergrate itself.



The other type is when an outside fuel source such as natural gas or propane is introduced through the intake and actually provides an unlimited source of fuel to the engine itself, causing it to overrev and destruct.



This second type is more common in the older Detroit two stroke diesels because they are supercharged instead of turbocharged and there is no limit to the amount of air they can produce.



The old Detroits have an air shut-off butterfly valve in the intake. So back to how to stop it. To be honest, unless you are standing in front of your truck with the fire extinguisher in hand you are probably going to be too late to stop it before its too late anyway. but it should not matter which type of fire extinguisher you use because they both work on the same principle and that is to remove the oxygen from the engine to choke it down. If the dry powder clogs up your air filter and stops the air flow then you have effectively cut off the oxygen supply to the engine. if the halon enters the intake and scavenges the oxygen then it has also done the same thing. Co2 would aso work just as well. Also if you have an exhaust brake you might be able to switch it on with the throttle closed and stop the air flow out which would also limit how much air could get in. Just a thought. In conclusion, if this happens probably the best thing to do is stand back and watch it from a safe distance and try to collect insurance on it.

 

[WBusa]

As far as I know there are 2 types of diesel runaway. One is a turbo runaway that can be caused by seal leakage causing a fuel source to enter the hot side of the turbo that causes the turbo to become similar to a jet engine. [... ] The other type is when an outside fuel source such as natural gas or propane is introduced through the intake and actually provides an unlimited source of fuel to the engine itself, causing it to overrev and destruct.

A coupla points (and I don't claim to be an expert):



1. If the oil seal on the turbo fails then the turbo can do more than just make like a jet engine... it can pump oil mist into the intake air... which causes the engine to overspeed destructively, if you're unlucky.



2. Aside from combustible atmospheres like natural gas (which, admittedly, most of us will never see if we don't work in oil fields or around pipelines, or park near a propane filling station), another kind of 'outside' fuel source (at least according to the lore) can be the car stopped ahead of you at the light, if its really shooting a cloud of hydrocarbons out its tailpipe right into your air intake. I'm thinkin that nowadays, with smog inspections and such-like, this prolly doesn't happen much. And if it does, hey, just drop 'er in gear, run him over, and problem solved! :-laf



3. Another cause quoted in the lore is an engine-oil overfill (like at Jiffy Lube). I suspect a whole number of things would have to go wrong simultaneously for this to be the problem... your blow-by tube would have to be blocked, I think, and your pistons would have to be shot bad enough to both pressurize your crankcase with exhaust and allow oil to be pushed into the cylinders big-time. If your CTD's in this bad shape it prolly deserves to be allowed to kill itself.



All in all, for most of us prolly the most likely scenarios are a leaking turbo seal or parking too near to a propane filling station (I've seen the kids who fill your cylinders dump tons of gas sometimes ).

 

[JohnE]

the 5. 9 was put in a case 2096 farm tractor in the 80's and i have seen one run away. not a pretty sight or sound. with my background of pulling i'd put in a guillotine right on the intake horn. JohnE why does it not surprise me that you know these things, must suck being a rocket scientist.



The (Young) Fat Kid

Andy

Every payday...

When you've been around as long as I then we'll see.



I also get to tech inspect for the RRVPA this year, too.



Another source for fuel rich air is at the local filling station. If the diesel pump is at the gasser island with lots of idling cars filling their tanks the air gets pretty rich. The idle can get pretty loping from sniffing free hydrocarbons.



Correct WBusa

The failed turbo will blow the oil into the charge air (intake) and supply lots of fuel to the engine.

 

[bodacious]

I don't think closing the exhaust brake will help must, my us gear has stuck on a few times when that happens the exhaust temp will shoot up to 1500 instantly with very little throttle. I have exhaust pressure gauge that help spot the problem pretty quick.

 

[Joe G.]

I wonder if a RV tank drain valve could be rigged on the filter end of the intake pipe to use as an intake air blocker for emergency use.

 

[CarlJensen]

There is an RV tank drain valve that is actuated by 12vdc. I have wondered if that would work as an air shut off. Don't know as it would be of heavy enough construction or if it would be fast enough. I have looked around at RV's while traveling but have not seen one installed yet. If it's too slow the engine would self destruct before the air got stopped! Put a manual in with a PTO cable to slam it shut?? Is it worth the worry over it??

 

[WBusa]

I'm gathering up info on the Roda Deaco ( www.rodadeaco.com ) and the Chalwyn ( www.chalwyn.co.uk ) air intake cutoff valves. Both have cable-operated models suitable for the CTD, both butt up against the mouth of the intake horn and are connected to horn and charge air tube via reinforced hoses, so should be quite simple to install... running the cable to the dash would prolly be the hardest part (there are also electric versions). Both look to be very high quality devices. Both are pretty durn pricey (looks like we're talkin' about five or six hundred $ here for the cable-actuated models). I may just be the only guy around here dumb enough to pay $500 for a mod I hope I never get to use, but once I have all the info together I might just volunteer to coordinate a group buy, see if there's any interest.

 

[TWafer]

I might be interested in one since I park right next to a propane filling station at work. Never have had a problem as yet but you never know. I do recall a few years ago having a semi blow his turbo in our parking lot. The blue smoke was just pouring out of it and formed a big cloud that just hung over the whole village. It ran about 2 minutes and the driver claimed he finally stalled it out. I suspect it seized myself but never did hear the outcome. They towed it away. If someone could come up with a good deal on some device, I would be interested.

Tim

 

[WBusa]

I wonder if a RV tank drain valve could be rigged on the filter end of the intake pipe to use as an intake air blocker for emergency use.

I like the idea, Joe (especially since the commercial air shutoff valves are so dang pricey) but I'd be nervous about never really knowing (until it was too late) whether the valve is actually up to the job. Would the thing break under the sudden high vacuum and just get slurped into the engine? Or would the high-velocity airflow maybe cause the valve to bind up and get stuck half-way closed? Or both? I would never be willing to test it at anything more than idle speed, so I'd never really know. Too many unknowns for my tastes. There are a lot of places where I'm generally willing to 'just try it and see what happens', but safety equipment isn't one of 'em.

 

[Joe G.]

The drain valves are pretty sturdy. Go by a RV store and take a look at one. They have to be to keep from dumping the waste tank on a rough road.

 

[Howard Durand]

I recall seeing vertical exhaust pipes with flappers on them to keep the rain out. I would think something similar could be used between the filter and the intake held open by a sear and trigger assembly which could be operated manually or electrically to stop a runaway.