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Liquid Propane Injection

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Liquid Propane Injection

Loserlv Loserlv
New User | Posts: 6 | Joined: 08/10
Posted: 08/19/10
08:06 PM

Every since I saw the Mothers Liquid Propane Injected car I have wanted to build LPI motor of my own.

I have a rust bucket 73 318 challenger that I'm building a resto mod out of. I can't decide what engine/trans to use. I want to have a daily driver that i can take to  the drags and auto cross on the week ends. So I'm thinking of keeping the small block. I want to keep the weight distribution closer to optimum. The other feature that I know i want to include is to use a Liquid Propane Injection system on this combo. Should i build a 318/390 stroker (original Engine)or should i go with a modern hemi thats already got some of the injection parts on it. I'm looking for at least 450HP. If my guess is right a build like the over-achiever on LPI would eliminate the need for race gas and make a really slick street motor.

is there any chance you guys will do an article in phr or em on propane.  

dfw61 dfw61
New User | Posts: 5 | Joined: 08/10
Posted: 09/11/10
04:51 PM

Check out the article "Cheap Mean 318" and I think You'll get many of your answers. I am looking at a 390" stroker too.  

Budnicks Budnicks
New User | Posts: 40 | Joined: 10/10
Posted: 10/29/10
11:34 PM

Loserlv & dfw61 fellow MOPAR guys hows it going you need to post more often we need more MOPAR related posts, I think there is cooling properties in liquid propane injection, I saw the Mothers show on HotRod TV and I don't think they even mentioned that benifit. Budnicks  
"Fill Your Library Before You Fill Your Garage" Good Luck  "Budnicks"

gtomustang gtomustang
Enthusiast | Posts: 457 | Joined: 06/09
Posted: 11/02/10
11:09 AM

If you stick with the LA, you'll remain numbers matching...for what that may be worth on a non-HiPo car.  Remember, that engine also ended up in trucks, which had EFI too. but that may have only been with the Magnum heads, which oil thru the pushrods and don't use rocker shafts.

how talented are you in engine building? A crate engine does offer a warantee, but I'll bet using a "foriegn" fuel will void it.  
Just because you can't do it...doesn't mean its impossible

Budnicks Budnicks
New User | Posts: 40 | Joined: 10/10
Posted: 11/02/10
02:09 PM

Loserlv I too will go to a 318/390 (4" stroker) when my 5.2 magnum in my 99 Dakota extra cab 4X4 needs to be rebuilt it only has 55K now so it will be a while, I realy like the trucks med. size but I want more torque to drive the mountain roads & snow where I live in the Seirra's, I can do this for about the same money as the crate 360's, I'm not trying to make a race truck, the magnum platform can make some decent power I have a bunch of bolt on's now but want alittle more torque & keep the same engine package in the truck but if your going for real power in a small block Mopar use the LA stuff is proven perf., Budnicks  
"Fill Your Library Before You Fill Your Garage" Good Luck  "Budnicks"

Roderunner Roderunner
New User | Posts: 12 | Joined: 01/11
Posted: 02/01/11
09:43 PM

There is a book available on building your engine for propane, by "S.A. designs", it should still be available somewhere! The propane tank is usually mounted in the boot, up high and longitudinally,so that when your fanging through the twisties you can feel the propane surging from one end of the tank to the other, not so good for handling! It's great for long engine life though, with nearly zero carbon deposited into the engines oil. I just did a google, the book is still around if your interested. Here's a google result :                                  A good place to start research for a propane conversion is Jay Storer's book:  Economy or Performance Propane Fuel Conversions for Automotive Engines.  It was published by S-A Design (ISBN 0-931472-12-1) and appears to be out print now.  A few book sellers still seem have it stock however.  Another useful book to read is Larry W. Carley's Propane Conversion of Cars, Trucks & RVs.  It is published by TAB Books (ISBN 0-8306-3103-8) but this book also seems to be out of print.  You may have luck finding these books in your local library.

These books are getting a bit old now, and don't cover direct injection, but are still a great read.  

Loserlv Loserlv
New User | Posts: 6 | Joined: 08/10
Posted: 03/31/13
09:44 AM

I know its been a long time since i posted. sorry. I started pit crewing for my dad when i was little. by the time i was 10 i could build a 440 race motor in my sleep. BUT. that was doing it my dads way. he tended to cut some corners. my grand father owned a chrysler dealership and my dad was a certified factory mechanic and body man for him. so he new how to do things but didnt have a budget. I worked various automotive jobs till i got bit by the aviation bug. planes are faster. so im just a back yard mechanic thats forgot a lot. i read alot and work on the kids cars. i put a new magnum 360 and a518 in my oldest sons 64 440. i cut up the harnes and built the mounts cut the tunnel etc. but thats the most challenging thing ive done in awhile. dont know if that answers your question.  

Bobs427 Bobs427
New User | Posts: 7 | Joined: 02/13
Posted: 04/02/13
04:09 AM

We all start out wanting to be within a budget. Then there's that one part you need now, and there goes your budget. So beit!

I had a friend that took 20 years to finish his project. (No Miss-Print) 20 years, and why? Because he wanted to stay within his budget. I built his engine, trans, and rear "once". Then resealed the engine, transmission, and rear, "2 times" during because they sat so long..."True story"! You guys that frequent the CHP site often, may have seen my post late last summer. I could go into detail but I won't.
  He lost 3 of his 4 friends, and one nephew in the process. He text me last summer to tell me. He has showed the car a few times and it came out really nice, but it took 20 years. I hope he reads this...
  My point is don't let the cost of a part stop your process. If the part is worth the money, and you need ityou may need to spend a little more.
  My son actually bought (2) cars for parts and stayed in his budget. Then made money selling the parts he didn't need...


dond1965 dond1965
New User | Posts: 48 | Joined: 12/13
Posted: 12/07/13
01:13 PM

a few thoughts on this subject...  propane has a high octane rating but low btu out put compared to pump gas, so.. you need lots of compression ratio, no need to worry about pre-ignition with 12 to 1 compression!! use alloy head castings to loose weight over the front wheels, an alloy radiator will help also.out back use multiple small capacity fuel tanks plumbed to a single delivery line that feeds the engine.... good luck bro