To stop a diesel you don't need to shut down the fuel, merely stop the
air flow. Worked for the diesel gen sets I ran in Vietnam and works for
an emergency shutdown for the 8V-92 Detroit in the bus here on campus.
Merely rig a flapper over the air intake (needs to be a positive seal)
that is spring loaded to close, use a solenoid to keep the trip
mechanism armed until oil pressure falls below a preset point, then trip
and let the flap stop all air.


Most of the 6-71 GM diesels that drove the smaller drilling rigs had air
shut of butterflies on the air intake manifolds. This was so that they
could be shut down even if natural gas came into the air intakes
insufficient quantities to keep it running if the fuel was shut off. It was
an important safety feature in the event of a blow out.
Apparently, it was as a result of a case where the diesels were shut off
during a blow out and didn't stop until a con rod came out of the side of
the crankcase and the ensuing sparks sent the whole lot up .

Regards

Tom