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-   -   Propane Conversion? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/propane-conversion-92332/)

kenton 06-29-02 11:07 AM

Propane Conversion?
 
I have done a search and can only find info on propane injection on a gas powered vehichle.

Has anyone done a full propane conversion? I was interested in what is possible with propane on a turbo engine. Since propane is supposed to be like 110 - 120 octane, wouldn't this actually be a good upgrade for hi boost cars?

Kenton

Jedon 06-29-02 12:28 PM

kenton,
I looked into this a while back and found a guy who made and was selling a first gen with a full propane conversion. Yes propane is higher octane so you could run more boost but it is like 70-80% the efficiency of gasoline so mpg would go down. The setup he had used a carb, most of the conversion systems seem to use a carb but there are places who sell fuel injectors for propane. Running propane would require a regualtor, tank, lines, and a fuel computer to control the injectors. There are kits that add propane in addition to gasoline to cool intake charges and add fuel, but after much discussion it was determined that water injection was probably a better idea.
If you want higher octane, go to the hardware store and pick up a few gallons of toluene, that's what the F1 guys used to run 1.5 liter turbo engines at 70+ psi netting 1500HP used....
-Jedon

kenton 06-29-02 10:41 PM

The reasoning behind this was more than just octane ratings. There is also the fact that gas prices are going up, and propane is cheaper, even if it does use more to power the car. Not to mention the fact that it is cleaner burning.

It just seems that everyone spends so much on fuel systems for cars to keep them from running lean and detonating, that they would be open to suggestions for things like alternate fuels. Especially ones that are becoming more and more available.

There is also the advantage that it does cool the intake charge when it is injected. Can anyone say smaller intercooler? This would probably gelp the radiator get more air to keep the rotary safe, and save you some money on the intercooler that you plan on purchasing.

Again, this was just a thought that I was hoping to get a discussion started on. I would be interested to know costs and advantages of this system, as well as eveyones view points.

Kenton

P.S. I know there is a 5% power loss when going from gas to propane, but I think the advantages clearly outweigh that. You can always just turn the boost up one or two more PSI with the higher octane rating and cooling properties of propane.

RonKMiller 06-30-02 09:19 AM

I've inspected engines torn down after running exclusively on propane, and it's amazing how clean they are, it will basically double the life of an engine, and maybe even triple it since it burns so clean. The only major by- products are trace CO2 and water vapor.
The downsides:

1)The conversion would be very expensive on an FD3S - probably at least a couple of thousand dollars unless you diy - good luck. Even still the components would run at least $1K.

2)There is no way you could run it on propane and gas - there would be no room for two decent size tanks.

3)It is sometimes very difficult to find propane and it's usually a pain in the ass to dispense it since you need
"help" from the retailer instead of doing it yourself.

4)It only has 90% of the energy of gasoline, 10% loss is hard to make up with higher boost, a colder charge, etc. It's a long stretch just to get back to the performance of a gasoline fired engine.

5)Propane really sucks in cold weather - in PA you would have a huge dropoff in hp in colder months unless you artificially warmed the tanks at night or injected them with Nitrogen. And this is only good as long as the tanks stay warm or when the Nitrogen pressure is high. Get down to 1/2 tank and it's all over.

6)Propane is not cheaper than gasoline in most areas - it's about the same at retail. If you had a bulk tank at your home, say 1,000 gallons, it would be a little cheaper.

The upsides:

1) a 300,000 mile 13B!

2) Go hug a tree! No air pollution.:D

Other alternative fuels: There are people running brand new turbo diesel Beetles on soy oil. But who wants to drive a turbo Beetle since you have to change the flowers in the bud vase all the time?:piss:

kenton 06-30-02 10:45 AM

Good points you made.

I am wondering though, is the drop off in colder weather due to pressure drop in the bottles, or does propane just dislike cold air?

Kenton

chachidu 07-03-02 03:22 PM

hey yall. I live in italy where there are many gas powered vehicles. Even jeep grand cherokees. I am not sure what gas it is though. It is called GPL...not sure what that means. There is also another gas which I think is propane. It is like 2,40 a gallon as opposed to 4 dollars a gallon for gasoline...but if MPG goes down maybe there is no point...I would love to see if anyone has done it on a 3rd gen

denver 05-25-08 06:37 PM

Anyone here can me explain , how this guy do this?
---> http://www.6speed.org/rx7/propane/ <---


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