Propane Conversion, Need Information

underboost · May 2, 2011

Hello, I'm new on the forum.

I own several gm truck, 5.3l and 6l and some ford 5.4l, and I looking for propane conversion kit.

I would like to find who built good stuffs and how it exactly work.

I'm also wondered to know how it will not light up all the alarm lights in the Dash.

I'm a snowmobile drag racer and I built turbo system for snowmobile, so I have some knowledge about motor.

Fuel is very expensive here in Quebec, and I would like to find some economy for my truck float, and I would like to know exactly how those kits worsk and how it cost, what performance, does someone ever tried it?

thanks for helping and sorry for my broken english.

VVT · May 3, 2011

We used to do all are company trucks. It works GREAT imo but there are a few drawbacks. If you want to do it right you should pop the heads and change out the exhaust valves and seats. I believe it was inconnel valves we had inztalled but this is in the 80's/early 90's so I cant swear by that. We did do a few without the head work and the engines became pretty sluggish after a 100K or so. Also we found that for whatever reason the propane plugged up catalytic converters pretty easilly so we would remove them. The cost for installation and kit on the last vehivle we did was around 3K all in and done. Dual fuel so it would run on either. Nowadays its too hard to find propane around for fill ups so we stopped doing it long ago.

But when we were in the heyday of propane it burns soooooo clean and we had one truck reach over 700K kms on the original engine and it still ran great when we sold it. 1981 GMC 2500 350 4spd manual ( bull low first gear ) so if you have convenient access to propane and your willing to do the conversion properly it works great imo. We also typically changed the cam shaft too as propane has higher octane but its less dense that liquid gasoline so they get a bit more doggy without a beefier cam to compensate.

Superior Propane in Concord did our conversions ( or some affiliate I cant recall but it was set up through them )

http://www.superiorpropane.com/external/bins/index.asp

tanked_darren · May 5, 2011

It is completely possible I wondered if the newer style gmc/chev could run this, but I seen some new ones at a work yard I go to sometimes, and they are on propane. But the superintendents get to drive new vehicles so I wasn't able to get into one - yet.

I will ask the guys in the shop next time I'm there about whats involved to do it properly and report back to this thread.

They have a gmc from the early 90's I drove one day last week, it had over 400,000kms on the clock, does propane really extend the life like that?

VVT · May 5, 2011

Yes the propane burns much much cleaner than gasoline. We ran ours 8-10000kms between oil changes and the oil would still look gold when we changed it. We must have had 20 different propane powered vehicles over the years and aside from the ones that burnt up exhaust valves and/or catalytic converters they were alll by FAR the longest lasting/running trucks Ive ever seen. We still have one 86 2500 GMC plow truck thats propane but it has a 1000litre tank in the box so we almost never have to fill it up lol. It still runs well but the body is rotting off the thing so it doesnt get driven far. Maybe 2000kms per year and all of it in snowstorms plowing out our yard and everyones driveways.