Propane gas.

[kris]

I am curious as to how propane gas works on a normal automobile engine. I have seen porpane conversion kits for sale out there. Also, I remember my father having a backup tank for his truck, that ran off propane. But other that burning cleaner, and costing alot less than gasoline, are there any other pros and cons to this? Does it effect performance, or the life of your engine? I am not looking to do this myself, but rather curious about how it works.

[Steel]

well im certainly no expert, but propane burns. Gasoline burns. There ya have it. just replace gasoline with propane and you have internal combustion!

[kris]

Originally posted by Steel
well im certainly no expert, but propane burns. Gasoline burns. There ya have it. just replace gasoline with propane and you have internal combustion!

Wow, thanks. I didnt know that.

[Steel]

oh sit, sorry i totally missed the point of your question.

[Rich]

Well, I know a bit about them, I actually did a conversion for a friend on a 1984 Chevy p/u.

Propane requires a good hot spark, meaning you need a 100% healthy ignition system. [Electronic ignition is a good idea]. You also need an excellent cooling system, since the propane regulator uses coolant heat to convert liquid propane to gas.

Also, since propane has less BTU's per pound than gasoline, you will probably average about a 10% drop in hp output. Keep in mind that higher compression ratios work better with propane. The average 8-9.5:1 is probably not acceptible. And last, but not least, ignition temps are higher with propane as well, so things like valve seats will wear quicker. If everything is set up correctly, engine life should be incresed significantly.

The one I installed was on a carb'd truck. Basically it required a different carb, regulator, tank, filler assembly.

Thats all I can think of right now.

[BeEfCaKe]

Biggest con... crash=kaboom!

[replicant_008]

Liquified Propane Gas has been used in Australia and New Zealand as an alternative to petrol for some time. Another alternative is Compressed Natural Gas.

LPG is less dense energy wise than gasoline but potentially has a higher octane rating allowing in theory higher compression or more advanced ignition to compensate. It also burns far cleaner than gasoline and performs better from an emissions standpoint. It's also substantially cheaper as both AU and NZ have reasonably abundant quantities of the stuff.

CNG is even less dense energy wise and is unpopular due to the losses in power when using this fuel.

In the mid 70s, conversions of larger more fuel hungry vehicles were quite popular to offset the rising cost of gasoline. Unfortunately, the losses in power (due to combustion technology etc), stabilisation in the costs of gasoline and the withdrawal of tax subsidies for conversions reduced the popularity considerably. There were also some problems with reliability associated with inadequate servicing and the lack of R&D associated with many conversions.

Ford of Australia have a LPG-powered variant in their locally developed Falcon range of large cars. Being LPG-dedicated (ie many are dual-fuel ie operate on gasoline and LPG) it provides some answers to the usual problems of LPG conversions ie the space consumed with the LPG tank, extra cost of induction and fuel delivery etc. From my understanding, Ford have provided a fuel injected LPG version which makes sense as there are a number of taxis and Police cars that use the stuff due to lower running costs over large distances offsetting the initial cost and their proximity to the limited distribution network (ie it's very hard to refuel outside of the major cities and only in certain service stations).

Holden also provide a LPG powered derivative of its Commodore (the basis of the new Pontiac GTO) but it's a less complex dual-fuel version.

[Porsche]

It says Propane Gas, and it's not specific.

On TRUCK! the guy installed a proapne injection on a duramx diesel Chey Silverado 2500. In this setup, propane was fed via a tank mounted underneath the truck and was sent right into the intake with an injector. The propane was used since it has air in it or has certian properties that can distribute more oxygen intot he combustion chamber. I think it has to do with the fatc that propane burns easier. Anyways it feeds in more oxygen allowing the engine too breath a little easier, but it used like a NItrous system and isn't a full-time use type setup.

They also installed a Nitrous system on the truck that produced sometihng over 426 RWHP on the dyno.

Both systems were by BullyDog.