Cutting off the air supply is a good choice. It was not one we were
presented with in the original post. Cutting off the fuel is often hard to
do quickly.

Firing a co2 extinguisher is also ok. Lets talk about the physics involved.
Even presuming your co2 stays cold enough to have an effect which I will
allow you. The moving parts in the engine are the ones that have to most
difficulty transfering heat energy. This is because the have small
lubricated contact surfaces to the non-moving parts. The ones that your
cold slug of co2 are going to encounter are the valves and the pistons.
Valves exchange heat through the valve guides, the valve springs, and the
oil. Normally excessive heat is being transfered from the valves to these
other items. But in this case we will allow that the co2 has cooled the
valve below normal operating temp. The cooled valve will contract. This
will increase the clearance in the valve guide and shorten the valve stem.
Neither of these is going to result in damage. Next stop is the combustion
chamber and the top of the piston. Again the moving part, in this case the
piston, is going to have the most problems with heat transfer. Pistons are
only able to transfer heat through the rings, the wrist pin, and the oil.
Again allowing that your co2 has cooled the piston lower than normal
operating temp. The piston will contract increasing the clearance between
the piston and the cylinder wall. This is not going to cause any damage
either. The head and block are simply going to contain far far too much
heat energy for your co2 to have a noticable effect. And the head and block
also have smaller contraction and expansion rates for the same temp change
as the valves and pistons. Even bringing other parts into the mix you are
always going to have a situation where you have cooled the moving part and
increased the clearances. And you simply are not going to be able to cool
anything down enough to result in a loss of material strength. This is why
you can't damage an engine with co2.


"Harry Krause" wrote in message
...
Lawrence James wrote:

LOL what do you do Harry, make this stuff up?

"Harry Krause" wrote in message
...
Snafu wrote:

"Harry Krause" wrote in message
...
Shut off the fuel supply, block the air intake and keep a load on
the
engine. You sure as hell don't want to pump CO2 down the airpipe.

Harry, I'm curious why you wouldn't want the engine to breathe CO2.


Because the CO2 is very, very cold and spraying it down into that hot
engine will likely turn the engine into scrap in short order.




--
Email sent to is never read.



Oh? You wouldn't stop a runaway diesel by cutting off the air supply and
shutting off the fuel? What would you do? Stuff rolls of TP in it?

As for the CO2, more than one diesel guru has indicated that the temp
differential would seriously harm the engine.

--
Email sent to is never read.