[Vwdiesel] Diesel working on liquid propane

[Doyt W. Echelberger]

I re-viewed some of the Bob Hoover sermons and emails on his propane 
project. This one surprised me:

"Actually, converting a water-cooled engine to run on propane is dead-simple.
Once I get the bus and bug running to my satisfaction I'll probably try my
hand at a propane-powered trike (!) and a turbo-supercharged propane-powered
1600cc Datsoon pickup.  Then there is the attractive prospect of direct fuel-
injection using propane..." Bob Hoover, Fri, 19 Dec 1997.  (my bolding and 
underlining.)

It certainly isn't impossible, and all our diesels get fueled by injector 
pumps.

One downside that I see is that when the injected liquid propane goes 
through its phase change to a gas, it makes a lot of heat disappear. That 
phase change would take place very near the injector tip. That space would 
need a glow plug that could deal with that situation, to get things started.

The other things I wonder about are (1) what pressure is required to keep 
propane a liquid at room temperature, (2) What is the pressure and 
temperature in the cylinder of a diesel engine at the moment a charge of 
propane should be injected during compression, (3) would that be sufficient 
to  cause combustion without a spark plug, (4) and would the resulting 
flame front be slow enough to provide an efficient push to the piston.

Also, liquid propane isn't a very good lubricant for the working parts of 
an injector pump.

This is an interesting thread.

Doyt