Diesel Runaway Engine

Kayteg1 wrote:

Bird Freak wrote:
In the old days working at Saunders leasing we would have a 318 or 671 Detroit run away. I have seen them suck one of the old phone books down the intake.

Mine is 318 or 8V71 and I was under impression that all those Detroits were equipped with killing flapper like mine is?
I play with it couple of times and it works. Kills the engine in split second, but you have to manually push the flapper back on the engine.
The 1972 pusher also has engine fire alarm. Working as I tested.
Coming back to the idea of stuffing something in the intake, I am not stranger working around running machinery, but when I open back door, I have 7 huge V-belts -some turning fan blades that will take your arm in a second, other running 7 kW alternator with pulley that will not mind your leg in it.
Getting there when engine runs few thousands rpm?
No thanks.

We had mostly 4070B IH cab overs. Our main problems came from rebuilds with the racks ran wrong.

Know how to stop a run a way diesel?

Blow-up the trestle.

Bird Freak wrote:
In the old days working at Saunders leasing we would have a 318 or 671 Detroit run away. I have seen them suck one of the old phone books down the intake.

Mine is 318 or 8V71 and I was under impression that all those Detroits were equipped with killing flapper like mine is?
I play with it couple of times and it works. Kills the engine in split second, but you have to manually push the flapper back on the engine.
The 1972 pusher also has engine fire alarm. Working as I tested.
Coming back to the idea of stuffing something in the intake, I am not stranger working around running machinery, but when I open back door, I have 7 huge V-belts -some turning fan blades that will take your arm in a second, other running 7 kW alternator with pulley that will not mind your leg in it.
Getting there when engine runs few thousands rpm?
No thanks.

In the old days working at Saunders leasing we would have a 318 or 671 Detroit run away. I have seen them suck one of the old phone books down the intake.

frankdamp wrote:
...Since the engine is using the lube oil in the sump as fuel, there's really no way to stop it, ...

Actually, the recommended method for stopping a runaway diesel is to strangle it: grab a large blanket or tarp and stuff it into the intake - it'll try to ingest it but once it fills up the intake it'll prevent air from entering and the engine will stop.

carringb wrote:


Yes and no!

Runaways are usually caused by a busted turbo oil seal, and the oil becomes the fuel. That's why those events are so smokey. Cutting the fuel does nothing, and neither does cutting power. Cutting air is the only way to stop it, but there's no way I'd want to put myself next to an engine that could spit a piston and any moment. Plus, the damage from overspeed is most likely already done.

The 2-cycle detroits did not have turbo on some models, yet they have been prone to run away. As mentioned above, I do have Fighter-Jet style switch on dashboard that drops big flapper on intake.
Those engines have injectors under valve covers and the leaks would run the engine at high rpm.
Such run away does not have much fuel, meaning the engine should be easy to stop with manual and clutch, but I agree that I would not stick around this engine for long.
Than the comments about shooting fire extinguisher into air inlet are good one.
CO2 would be the best, but whatever extinguisher you have, -it should stop the engine.
The only worry would be coaches with double air inlet.

hooligan wrote:
I was told the reason the air intake for diesel RV & trucks is up high to avoid fumes such as a gasoline spill which could cause a runaway.

Most diesel trucks and DP's have the air intake located in about the same height relationship to the engine as passenger cars. Most current production Class 7-8 trucks have under the hood air filters just like passenger cars, for aerodynamic reasons. The intakes are located to minimize the intake of road dust and water. It's extremely unlikely that in a gas spill the heavier than air fumes would be ingested into an engine in a high enough concentration and long enough to cause a runaway engine.

I was told the reason the air intake for diesel RV & trucks is up high to avoid fumes such as a gasoline spill which could cause a runaway.

Years ago, I was a Chief Engineer on an older Tug Boat. We had yard workers painting the Engine Room using Spray Painter and somehow they managed to hit the Start Button on a 6-71. I was on the opposite side of the ER when I heard it crank up and take off! I dove for the Trip on the Blower (a flap that seals off the air) just as I hit the trip she let go. To this day I have very little hearing in my right ear from the noise from when she blew.

prstlk wrote:
Honestly, have 2 cocktails, or 4 beers, then look closely at the smoke. I swear I saw historic figures, and maybe some relitives. Or maybe that was 3 cocktails?

You're right, I think I saw Jimmy Hoffa and JFK. :?