Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
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I'm not sure whether this is a relevant topic on this forum, but I don't know where else...
I'm considering a conversion to propane for my car. I've done some research, and I think I'd like to go with an electronically controlled liquid propane injection system, rather than the vapor carbureted or vapor injection setups.
The main thing that's troubling me is how to intorduce the liquid propane into the air flow. Would a standard FI injector work with liquid propane? The only drawbacks I can see in my inexperience is a non-ideal spray pattern and the potential to possibly freeze the injector up. I'm not worried about the spray pattern too much, and I think the injector's proximity to the combustion chamber would keep it from freezing up.
Can enyone find any flaws in my logic?
The engine will be a dedicated propane engine built with a cam and compression ratio to take advantage of the higher octane rating and burn charicteristics of propane. A TPI or SuperRam manifold will be the intake system. I'm hoping that a stock GM ECM can be used for control, with the only change being the fuel map and spark tables.
Thanks!
Jason
__________________ Project: 1972 Blue Corvette Coupe, 383 small block... VB Perf+ susp... Tremec 3550 5-speed... Soon to be DFI... Already driving me directly to the poor-house... http://jason.3will.net/vette/
Driver: 1972 Blue Camaro Coupe, 350 small block, Edelbrock Performer intake and carb... TH-350 w/shift-kit... http://jason.3will.net/camaro/
they have these kits all over europe and is a very popular swap as gas over there is over 4$ a gallon and propane is about 1.25, the kits themself are about 1,000$ but propain runs about 108 octain level so you can run about 12:1 no problem. i would have no idea where to look for one of these swap kits.
This webpage is about a system similar to what I want to make... just a bit more expensive than I want to spend: http://www.bi-phase.com/Engl/LPEFI/perform.html
My main reason I want to convert is novelty, but I also like the idea of a clean burning car.
I'm still not sure if I want to do it, right now I'm just researching.
-Jason
__________________ Project: 1972 Blue Corvette Coupe, 383 small block... VB Perf+ susp... Tremec 3550 5-speed... Soon to be DFI... Already driving me directly to the poor-house... http://jason.3will.net/vette/
Driver: 1972 Blue Camaro Coupe, 350 small block, Edelbrock Performer intake and carb... TH-350 w/shift-kit... http://jason.3will.net/camaro/
Originally posted by rezinn Why do you want to switch to propane? You would have to have pretty high compression to make up for the loss in power.
Actually, the loss of power aspect of propane is pretty minimal. It runs so clean that the engine just never carbons up and loses power. A 10 to 1 compression ratio is perfect with propane.
HP loss won't be minimal. You will have to do some mods if you want the engine to make up the power loss. Back when propane was cheap, a lot of farmers used propane in their pick-ups and such. I would stick with vapor injection. It's simple and the brunt of the pressure will be in the tank. Once unpressurized, liquid propane turns to vapor. Do some searchs on the net for propane conversion.
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Originally posted by 82camaro HP loss won't be minimal. You will have to do some mods if you want the engine to make up the power loss. Back when propane was cheap, a lot of farmers used propane in their pick-ups and such. I would stick with vapor injection. It's simple and the brunt of the pressure will be in the tank. Once unpressurized, liquid propane turns to vapor. Do some searchs on the net for propane conversion.
I ran a propane powered Impala with a 350 for 15 years. I couldn't tell any difference in power between gas and propane. And over that period of time you can bet you booties that on gas its performance would have fallen off drastically, seeing as I put about 500,000 kms on it. On propane it ran like a charm.
Don't believe everything negative you read about propane. In practical everyday useage it is excellent
In fact, I only had to make one repair to the propane system in all that time. A gasket on the mixer gave up and started to leak antifreeze. It cost about $20 to fix. I didn't have to do one other thing with it, except change the fuel filter twice.
If I had been running gas, well, it would have needed a carb overhaul at least every 18 months, and fuel pumps who knows how often? (Propane requires no fuel pump but is delivered to the engine under high pressure from its tank.) Not to mention valve jobs, spark plugs, etc.
Propane is almost identicle to fuel injection, in as much as it atomizes its fuel completely and distributes it very evenly to all the cylinders.
Am I gushing? If I am it's because propane works so very well.
Last edited by Sitting Bull; 01-09-2002 at 12:29 PM.