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LPG conversion...


m12-lrv
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Any interests in propane conversion? I have a spare ea81 block laying around and im considering propane conversion just for grins... ive aquirred a book that goes over converting smaller 4 stroke motors but the math should all carry over. ive seen kits for v8 motors but none for smaller. I may use an existing carter webber that i have being a single barrel, or the hitachi seeing that those are more common. other option is just to fab a new one up from scratch, and might be the easier route.... any one ever try this?

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Speaking from an industrial mechanic's point of view which only means really work on LP units every day.  I would love chat this topic not even something I would want to do myself personally.  Have a couple of questions though.

 

1.  Are you very patient?

 

2.  Do you have a lot of spare time?

 

3.  Do you plan on driving this everyday?

 

There are so many variables that are just different with LP.  For instance...  Many people try to do this conversion on an engine with high miles.  They think that since the engine is within specs according to a Chilton or Haynes it is OK for LP.  Compressions have to higher and more even simply because LP is more sensitive to compression differentials.  Then they try to adjust regulator or regulators cylinders that are uneven.  It will run good till warm.  It will run bad cold then runs good. 

 

Cheers,

 

Eric

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I ran propane on a subaru 3.0 six with turbo worked very well and we have some ej motors runing on propane all turbo works well we use a cut down ej 2.2 harness with just spark wireing no efi

cool this gives me hope! The motor however is probably a higher milage and to be honest the condition of it is uknown. I just happen to have it lying around and a couple spare carbs, and all the free time I need currently. plus it sounded fun!

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Id probably look for one that fits in the spare tire compartment (disclaimer on not knowing if there are regulations against this for safety in a head on, you will have to account for your own due diligence).  short run for fittings and hoses, and keeps the gas out of the cabin.  Id try for a dual system if you can.

 

id also research which stations in your area will fill it, lots may say no.

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A few things to point out... You can't just throw a regular carb on and go. Won't work. Second, you need a minimum of 9.5:1 compression or a small engine like that will be a gutless t*urd and run like garbage. Third and most important... The tank CANNOT be mounted in the engine compartment or inside the passenger compartment. Aside from the absolute stupidity and safety issues, it's a violation of federal law. You have to have a specially rated horizontal tank mounted where your gas tank was and should build a safety cage around it. Lastly, if you want any kind of dependability out of it, IE: long life, you'll want forged pistons, moly rings and stainless exhaust valves. I'm the LPG tech along with being the driveability and diesel guy at work. I've rebuilt more than a few LPG and propane engines and conversions on carbed rigs time consuming and frustrating. What was #1 at the top of this thread.... Are you very patient? Not trying to discourage you, but you really need to research this. There's a reason LPG didn't really take off until fuel injection came along

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A few things to point out... You can't just throw a regular carb on and go. Won't work. Second, you need a minimum of 9.5:1 compression or a small engine like that will be a gutless t*urd and run like garbage. Third and most important... The tank CANNOT be mounted in the engine compartment or inside the passenger compartment. Aside from the absolute stupidity and safety issues, it's a violation of federal law. You have to have a specially rated horizontal tank mounted where your gas tank was and should build a safety cage around it. Lastly, if you want any kind of dependability out of it, IE: long life, you'll want forged pistons, moly rings and stainless exhaust valves. I'm the LPG tech along with being the driveability and diesel guy at work. I've rebuilt more than a few LPG and propane engines and conversions on carbed rigs time consuming and frustrating. What was #1 at the top of this thread.... Are you very patient? Not trying to discourage you, but you really need to research this. There's a reason LPG didn't really take off until fuel injection came along

yes im well aware of the complexity of the conversion. If I can get said conversion to work on A SPARE MOTOR, I would then transfer the conversion into a car. If it goes that far I will be using a forklift tank mounted in the bed of a brat. who gives a f*ck if it doesnt work either? ever just do something for grins :) :) :) ? I'll have to look into the laws around lisencing the the car for street use, but whats dumb about experimenting with alternative zero emissions fuel any way.

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Id probably look for one that fits in the spare tire compartment (disclaimer on not knowing if there are regulations against this for safety in a head on, you will have to account for your own due diligence).  short run for fittings and hoses, and keeps the gas out of the cabin.  Id try for a dual system if you can.

 

id also research which stations in your area will fill it, lots may say no.

duel fuel system is the dream but I think its going to be for LPG only. And I fill propane tanks all day at my work so avalibility is no issue for me

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Never said any of it was dumb EXCEPT for mounting the tank in the cab or engine compartment. I'm all for zero emissions. I also do the hybrids and the Volt. Just pointing out you're looking at thousands of dollars (3 at least) for a safe, viable system.  You legally can't use a forklift tank. Huge fine if you get caught. I'm not trying to be an a**. I just know people who have been killed trying to half a** this stuff, or worse, kill someone else in an accident. I do all kinds of sh*t just for grins. Lifted a J10 pick up 8" with all custom suspension I built. Ramped 786 and would still carry a camper with only 2" of squat. Dumped in a 400hp SB400, 5spd, 3/4  ton corporate Chevy running gear and built a 30 gallon fuel cell for it since the pos came with a 16 gallon tank. people asked why.... Because I can! lol I get it. I'm just saying don't cut corners and do lots of research.

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I too have done all kinds of stuff just to do it...  I did just want to point out some facts.  I don't know skishop69 but seems to be your go to guy.  I do like the topic though  because it is something I work with.  As I was looking at a forklift tank mount figuring out how to invert it mout it to have REMOVEABLE 15 gln. tank.  I also think there is a tank valve head cap law that is required?  Similar to putting tank caps on my bottles in my service van.  Even started staring at an indistrial IMPCO system only because it is simple looking....  So I too don't think it is dumb.  I think skishop69 was also just giving you facts.  Love your thread. 

 

Eric

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As far as im probably going to get with this is making the carb and at least get a motor to run on a stand. I want to document my trial and error on doing this so if someone wants to build a motor more specifically around running on LPG they can take what I come up with and run with it. 

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  • 4 weeks later...

I have my EJ swapped Brumby running dedicated LPG and have done now for 7 years....i swapped it to LPG when it still had the EA81 in it(supercharged it for a bit until i got sprung by Mr Plod), did about 25'000 miles before it spalled the cam (have suspicions about the oil i was running being the cause) swapped in a EJ18 (really high mileage= cheap, needed the vehicle going 'now') carb and dizzy motor ran that for 10'000 miles until it dropped a valve then swapped in the good EJ22 9aslo carb and dizzy) thats in it now....that has over 100'000 miles on it.

 

one thing if you are going to convert it to LPG is to use a variable venturi like an IMPCO....i started with a fixed venturi because i didn't know better then swapped to a variable (BLOS)...the difference is unbelivable

 

the impco CA 55 mixer is bang on the right size(hp rating) for a EA81....altho you will not be able to mount it on top of the factory carb and still close the bonnet.

 

i fitted it all myself....lol i started out not knowing anything much about LPG tuning and now i get the occasional phone call (from the installers where i get the annual safety check thats needed here done) saying "um...can you come have a look at this?"

 

also have a 12.5-1 compo EJ25 with SOHC EJ20 heads and delta torque cams that i need to finish putting together....that should run well on LPG

Edited by LPGsuperchargedBrumby
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Matt bought a realy cool mpi propane setup was showing me last night tees into the injector feeds and can run deul feul was very neat looking kinda like a vortec mpi but with propane. We are going to test it on untested 2.5 stroker turbo engine has 10-1 comp roller cams and turbo legacy heads with mpi propane should work good

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Never said any of it was dumb EXCEPT for mounting the tank in the cab or engine compartment. I'm all for zero emissions. I also do the hybrids and the Volt. Just pointing out you're looking at thousands of dollars (3 at least) for a safe, viable system.  You legally can't use a forklift tank. Huge fine if you get caught. I'm not trying to be an a**. I just know people who have been killed trying to half a** this stuff, or worse, kill someone else in an accident. I do all kinds of sh*t just for grins. Lifted a J10 pick up 8" with all custom suspension I built. Ramped 786 and would still carry a camper with only 2" of squat. Dumped in a 400hp SB400, 5spd, 3/4  ton corporate Chevy running gear and built a 30 gallon fuel cell for it since the pos came with a 16 gallon tank. people asked why.... Because I can! lol I get it. I'm just saying don't cut corners and do lots of research.

 

You absolutely can use it as long as it is above the bed.

 

They add propane to cummins diesels all the time, and it's perfectly legal as long as the tank is above the bed and secured.  BBQ tanks are even fine like that.  It's a below deck or "enclosed" installation that requires specifically certified tanks (like RV tanks)

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A few things to point out... You can't just throw a regular carb on and go. Won't work. Second, you need a minimum of 9.5:1 compression or a small engine like that will be a gutless t*urd and run like garbage. Third and most important... The tank CANNOT be mounted in the engine compartment or inside the passenger compartment. Aside from the absolute stupidity and safety issues, it's a violation of federal law. You have to have a specially rated horizontal tank mounted where your gas tank was and should build a safety cage around it. Lastly, if you want any kind of dependability out of it, IE: long life, you'll want forged pistons, moly rings and stainless exhaust valves. I'm the LPG tech along with being the driveability and diesel guy at work. I've rebuilt more than a few LPG and propane engines and conversions on carbed rigs time consuming and frustrating. What was #1 at the top of this thread.... Are you very patient? Not trying to discourage you, but you really need to research this. There's a reason LPG didn't really take off until fuel injection came along

 

I would suppose that the fuel cylinder from an RV would be of the right type to be made road legal

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