Test Running a diesel on propane

   / Test Running a diesel on propane #1  

Farmall

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Jan 16, 2005
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Is it possible to run a diesel on propane through the air intake for test purposes? I have done this on gas engines before. It seems like it almost wants to catch, but does not. Thanks for replies.
 
   / Test Running a diesel on propane #2  
The two have a significantly different hydrocarbon makeup and are refined at different temperatures, so their reaction to compression would be very different.
Gas engines in 4wd vehicles are sometimes converted to propane due to the fact that they can operate at more severe angles without fuel supply problems associated with carburetors and gasoline. It seems logical that its ability to fuel gasoline engines would make it an unlikely replacement for diesel.
How about it, fuel experts...??
 
   / Test Running a diesel on propane #3  
I would be VERY careful. In fact I would not try it.

Diesel is a flamable fluid, it does not explode in the cylinder. Pressure from the piston driving up in the cylinder creates heat, as the diesel fuel is injected into the cylinder, it burns and causes expansion which drives the piston down.

Gasoline and Propane, when used inside internal combustion engines are exploded by a spark plug, the resulting explosion drives the piston down.

Propane in a diesel engine will have no ignitor other than the pressure which generates heat, it is going to be timed completely differently and it is likely that the timing issues alone will create a situation where IF the propane ignites it will very likely create a small explosion at the WRONG time and I have no clue if the consequences would be good or bad, but I suspect it simply either won't work or it will be dangerous.

I know of know multi-fuel engine that would allow diesel & propane to be substituted for each other.
 
   / Test Running a diesel on propane #4  
Propane is to a Diesel Engine as Nitrous Oxide is to a Gas Engine.

You can cause some serious damage to the engine if it's not done properly BUT if done properly it can hot rod the crapola (technical term) out of a Diesel engine. I'm not sure of the practicality of doing this to a Tractor engine but if you have the money and free time then it could be fun.

Check out this site for an idea of how it works in diesel trucks:

http://www.dieselperformanceproducts.com/home.html

http://www.bankspower.com/tech_propane.cfm
 
   / Test Running a diesel on propane #5  
Interesting links, but it seems that propane is ADDED to the diesel to possibly improve performance. The benefit seems dubious, as do the claims, but I suppose there is a performance enhancement, the real question is what is the real cost in engine reliability and shortened lifespan.

I may have misunderstood the original post, but I was under the assumption that he wanted to run the engine on propane INSTEAD of diesel.
 
   / Test Running a diesel on propane #6  
It is 100% absolutely impossible to run a diesel engine only on propane taken in through the air intake alone, ie without any diesel fuel injected into each cylinder.
 
   / Test Running a diesel on propane #7  
Yes, you would always need some Diesel in the mix. Propane will not ignite without a spark.

It would be fun to hook up a Propane tank to the tractor for those times when you need a little more HP at the PTO!

; )
 
   / Test Running a diesel on propane #8  
The diesel will do very well on just straight propane or natural gas. Provide a souce at the air intake and watch the run away to self destruct mode. Other than shuting of the air intake there is no way to shut down the motor unless it's stalled.

Some companies require positive air shut off for diesel engines when they may be operated in an area where an unexpected release of a cumbustible vapour could occur.

Egon
 
   / Test Running a diesel on propane #9  
Egon, how would you get it started with just straight propane?

I get the concept of using propane as a boost, similar to NOX. I even understand your comment about requiring a positive shut off when working a diesel in areas where there is combustable vapor, but it seems (maybe I am confused) that in both cases there is diesel present, or at least there was diesel there originally to heat up the engine to operating temperatures (hence the need for air shut off if propane is in the air).

But just starting it up on propane from a cold engine? Can that be done?

Personally I wouldn't try it on my fleet, or my tractors, but now I am just curious.
 
   / Test Running a diesel on propane #10  
I don't know why you're trying to do this. Propane sucked into the air intake would likely be way too lean in fuel/air ratio to combust. Think you'd have to inject the propane as a liquid through the fuel injection system to work at all.

I wouldn't want to mess with propane. It's heavier than air. Any tiny leakage anywhere is liable to put a propane vapor puddle at your feet that could ignite and set you on fire. (This is why gasoline is so dangerous; it has butane in it to help make engines start; butane evolves and goes down around your feet.)

I worked in plants filled with propane or using huge propane or propylene refrigeration systems for 31 years. I won't have the stuff in my house, much less in a vehicle in a garage. Only way I'd use it on a vehicle would be a gas tractor always kept out in the open.

Ralph
 
 
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