CO2 anti-runaway system ideas...

[luvrbus]

The emergency shutdown as you call the air door was installed for 1 reason and that was to kill the engine when a injector stuck not allowing the engine to stop it never was intended to stop a run away engine and it won't

good luck

[TedsBUSted]

The emergency stop door door may not stop an engine completely, but, it will gag it to run slow enough so that it won't blow-up and can be otherwise stalled.

Luvrbus - How do you classify a runaway? Inhaling gas fumes for fuel?
The few I've seen take off on crankcase oil or uncontrolled fuel seemed to choke up around maybe three grand; still plenty fast in a cloud of smoke and noise.  

I've heard that if they're inhaling gas fumes they can really buzz up the revs. I remember hearing a story about a broken natural gas line over-fueling a Jimmy, but I don't recall the details exactly. Actually two stories, one was a truck that knocked a gas meter off of a building, the other was a stationary engine that caught fumes somehow.

Ted

[luvrbus]

Ted a 4 stroke will do the same thing with natural gas I have seen the old Cat engines build up fuel and oil and run wild for a few seconds fwiw I had a 17A D-7 that was bad about it and it was a 1200rpm engine
Never have saw a DD runaway on crank case oil have saw a few get wild after days of idling

good luck

[Tim Strommen]

A diesel engine runs on compression - it stands to reason that a good method to stop the engine in a non-destructive way on a 2-stroke DD would be to have a valve that can vent the airbox after the blower, and bypass the buffer switch on a jake brake system.

Essentially, you'd wire a valve that would release the roots-blower/turbo pressure down to ambient or nearly ambient, then forcing the Jakes on (bypass the normal control circuits) would blow the pressure from the cylinders before they can support combustion - and would do so very rapidly...

It sounds a lot safer to me than having to carry a charged cylinder of inert gas on the bus.  This is similar to the system on smaller diesels that have the engine equivalent of a compressor's "unloader" essentially disabling the unit.

-T