Propane conversion

[anziconda]

Thinking about putting propane on my old chevs that are mainly used for wheeling. Anybody done this?? What are the pros and cons?? Sounds like propane burns at about 115 octane so it should run sweet. I've also heard that since you're burning a gas and not a liquid, the plugs never foul and engines last longer(no fuel washing the cyls, no carbon deposits on the valves). Any input or info about a kit would be appreciated

 

[ruffryder]

Thinking about putting propane on my old chevs that are mainly used for wheeling. Anybody done this?? What are the pros and cons?? Sounds like propane burns at about 115 octane so it should run sweet. I've also heard that since you're burning a gas and not a liquid, the plugs never foul and engines last longer(no fuel washing the cyls, no carbon deposits on the valves). Any input or info about a kit would be appreciated

Big blocks? I know in the late 70's and early 80's a lot of big motors (busses, dumps) were converted over to propane, might be a good place to score some equipment for a good price. The rest I can't help you with.

 

[Mafesto]

Was visiting with a customer yesterday who has his 8.1 converted to LPG.
He claimed 10% poorer fuel mileage. (not bad when propane is around $2/gal)
Says he has about $5000 into the conversion & can switch between gasoline & LPG with a flip of a switch.

To correct the original post, the engines should last longer since propane is much, much cleaner than gasoline. (ethanol is much cleaner than gasoline as well)

 

[anziconda]

The engine that I'd be doing is just the good ol 350 sm. blk. chevy engine...Someone has to know something about this or know someone who has done this...thks

 

[dangerfield]

The engine that I'd be doing is just the good ol 350 sm. blk. chevy engine...Someone has to know something about this or know someone who has done this...thks

Used to do conversions back in the 80's when propane was cheap. You loose HP, mileage is a little less, and it can be hard on valves if you work an engine hard, used to have heads made with hardened seats & valves. It doesn't burn as a gas, it is converted to vapor prior before it's burned.

 

[AltitudeinD]

I run LP in my GMC6500 w/a 366. Pull about 14k every day, truck weighs 11k and I get around 13mpg. Not bad at all IMO when LP is 2.29gal. The sacrifice is the power. She's a dog but with a split rear it's not so bad.

 

[rocketron]

Had it on an old chev, and the power was terrible (you could kick a turd past it on a hill). Fairly cheep to run but sucked to drive.

 

[racingpit]

I am looking for a kit for my 79 GMC 350.... Gasoline just costs too much! Anyone have a kit I can buy?

 

[mulestar]

Used to do conversions back in the 80's when propane was cheap. You loose HP, mileage is a little less, and it can be hard on valves if you work an engine hard, used to have heads made with hardened seats & valves. It doesn't burn as a gas, it is converted to vapor prior before it's burned.

Had a 68 Ford with a 390 converted to propane, ended up buying the lp heads for it, wiped the originals out pretty fast. I believe it cracked one of them, cant remember for sure, long time ago, just knew we had to get new ones. Couldnt tell you what needs to be done with the Chevys, might want to check that out.

Do the newer vehicles need any major changes? Heads etc? Just curious, I may be interested in doing the same with a newer one if I decide to get rid of my diesel. $4.20 a gallon is getting tough to swallow.

 

[anziconda]

Had a 68 Ford with a 390 converted to propane, ended up buying the lp heads for it, wiped the originals out pretty fast. I believe it cracked one of them, cant remember for sure, long time ago, just knew we had to get new ones. Couldnt tell you what needs to be done with the Chevys, might want to check that out.

Do the newer vehicles need any major changes? Heads etc? Just curious, I may be interested in doing the same with a newer one if I decide to get rid of my diesel. $4.20 a gallon is getting tough to swallow.

Just an idea for you, I have a friend that has a Dodge cummings diesal and he had propane installed as a supplement to the existing fuel system. It has a controller to adjust the amount of propane going into the engine. I rode with him and on setting 6(it goes up to 10) it was a freaking power horse. Another thing that he showed me was the instant reading for MPG. When he had the system turned off it showed and instant reading of 16 MPG. As soon as he turned the propane on to level 1 his readout showed 31!!! Don't know how accurate it is but he's very happy and says he only has to fill the propane about once a month. If I owned a diesal I'd look into this for sure. If anybodys interested I can probably get the info from him and post it...Now back to the old chev 350 any more input?????

 

[leisureexpress]

Ok, to take advantage of propanes octane you can do 1 of two things (both is best), advance the timing and/or build a higher compression motor to take advantage of the higher octane. Building a higher compression motor is good if propane is the only fuel, but could cause problems if you want to go to a bi fuel setup (with low octane gasonline available-would run fine on propane). One of the reasons propane and its octane cause heat problems (burned valves etc) in gas motors is because higher octane fuels burn slower thus if not ignited earlier burn later resulting in less power due to max pressure of the burn too late in the power stroke. Also by the time the fuel is all burned it is way late in the power stroke and coming up on the exhaust stroke and it heats up the valves as the hotter/just barely burned mixture exhausts.

More later, but in the meantime spend some time on this site, there is ALOT of good info: http://www.cars.rasoenterprises.com/

Another great site to help select components is: http://www.impco.ws/download/Web-Catalog.pdf

I also have a site to buy the components at the best prices I have found: https://www.helmarparts.com/shoppingcart.asp?Check=True

More later.....

 

[94fordguy]

My dad loved running vehicles on Propane, he had his '79 Lincoln Town Car with a 400 engine converted at 12,000 miles and he had it dyno tested... GAINED 12 horses All the components were IMPCO Brand and they worked VERY well, that engine ran like a top, it would easily run as good today if he wanted to restore the rest of the car to reliable order.

We've also had several other rigs on propane, all but 1 with all IMPCO components, and that was the only one we ever had to fiddle with (vibration would mess with the mixture adjustment for the low speed parts, easy fix, just irritating).

Best advice he ever got, DON'T go dual fuel, go one or the other... He still hates driving anything that isn't propane.


Edit: Oh, he also pulled a 3,500 lb utility trailer quite frequently, and even went wood cutting with it every year. That car did every bit as much work as any truck would... took a real beating in the towing department and kept on going

 

[hilinerider]

propane is like my natural gas motors, to get power out of it you have to advances the timing usually 30 to 35 degrees, and get the compression up to 10to1 or better, thats why the old cars did good with it they had better compression, also you have to put in the hardened valves and seats or they melt right out of them, impco is tops in natural gas engine carbs and make some sweet stuff for propane vehicles, i know the shcwans trucks are all outfitted with it. all the sytems work the same that i have seen, the propane comes into the atomizer as a liquid and is then warmed and atomized to a vapor and fogged into the intake, unless the have a actual impco carb where the propane comes in as a gas and is then mixed by the carb right on the intake. ford tuned intake systems like the 90's 302 - 351 engines would hardly run on propane and was told lost like 30% hp on the early atomizer systems.

 

[anziconda]

ttt

 

[euge]

I have done this to two offroad Rigs, a 4 cyl toyota and a 500 caddy
contact gotpropane.com about $1150 for the V-8 and you will need a tank (forklift) worth every penny. You can advance youre timing also propane is approx 110 octane