I've seen some F250's in the past with a 390 propane conversion. Is this a good idea for the 390 engine? Can it take the propane conversion pretty well? And, (newbie time) Is the propane fired directly into the cylinders (kinda like a diesel) or is a spark plug used to ignite it? Any websites I can be pointed to that would show exactly how a propane engine works?

 

i just read an aticle that four wheeler put out where the put a propane kit on an older
chev. one place to check is technocarbs equipment ltd www.technocarb.com ive seen
a kit put on an old international with no trouble to the engine in fact the engine runs cleaner with propane than gas often going 10,000 miles between oil changes with the oil coming out the same color it went in and yes the engine will still need plugs actully about all thats done is to place a unit that much resembles a throttle body unit on in place of the carb and installing a regulater under the hood and plumbing it all in. and after installing the kit on their truck the folk at fw reported an increase in the horse power of their truck.

 

the propane conversion will be hard on the engine, if you do not install special heads, pistons and valves, (not to mention the hoses and tank needed) also a special air cleaner set up is needed because the propane is entered from the top of the carb then in to the the intake and this allowes you to switch form propane to gas with the flip of a switch. But i would not recomend it. My dad ran propane through his 79' 460ci and even with the special heads he still had to replace them and then got rid of the propane because in the long run the repairs cost more than you can save by running propane. If it was me i would just stay with gas!!

 

I know that when we put gas in the fork trucks, they run like crap, and the inside of the tail pipe turns black. When run on Propane, you can run your finger on the inside of the tail pipe and you finger comes out spotless everytime. On propane, the lifts have much better throttle response and power. These motors are 4cyl Nissan motors, but i thought you would like to hear some expirences. I dont know about the need to change engine internals to run propane, but i do know that you can run higher compression ratios when you run propane.

 

my step father used to run the garbage truck for the city (the old international i spoke of ) when the city purchased this truck it had ran on gas for meny years the first thing the city did was to switch it over to propane that was 15 years ago, as far as i know they are still running the same truck and i know they didnt do anything to the engine i also reciently had the chance to look over and drive a gmc that had a built 350 that was fired on propane the only thing they did to that truck was to put in sodium filed valves i wont say that there isnt engines out there that propane wont hurt but i havent ran into any

 

The natural gas/propane utility company in my city has outfitted propane on all of their service trucks. They are stock chevy 1500's and they seem to work great!

 

I started thinking last night about what4020loaderman said and i must agree with part of what he stated I had the chance to talk with a gentleman a few years back. He worked for a propane distributer and he owned a 80's F250 4x4 with a simular set up on it where you switched from gas to propane and he told me the same thing 4020loaderman said he had had nothing but trouble wit the switch and the valves that opened the gas or propane if I was to do such a swap I would definatly stay away from that kind of setup the ones I was talking about were straight propane fired setups no gas involved also a about 8 years ago a friend bought a 1984 F350 dually delivery truck it had a propane fired 300 straight six in it with over 200,000 miles on the original motor no work do internally my friend decided to put a flatbed on the truck and when he did he changed it back to gas. this truck ran beautifully prior to the gas swap. he only got another 5-6000 miles and blew a rod. it seems that the problem comes more from introducing gas back into the motor than the the propane. maybe someone out there can explain way that is,but I have heard of this on several occations that someone took a truck that ran propane and switched back to gas and the motors don't last long. also a few other things to look at before you make a decision is what do you plan on doing with this truck. remember you'll lose about 2-2.5 feet of the front of your bed for the tank also you have to plan alot further for any trips you wan't to take the truck on I've heard that there are places that you have difficulty finding propane.

 

All the government trucks have propane in them, there gutless 3/4 tons.

 

Just out of curiosity, what government trucks? I work for the government and have yet to drive a propane powered vehicle. I'm not digging here, just curious to see maybe where you are at. Could be a regional thing I guess.

-Abrams

 

some of the problems ya'll are talking about may be due to the fact that the propane only needs about an 1/8th of the air flow of gasoline so if you are swiching back and forth you need to mask/unmask the airfilter for the approprate fuel. I saw a friend of mine converted an old olsmobile to run propane and gas. you can do it with parts of the shelf at the propane supply store, you need a cylinoid and regulator to turn on/off the propane and if you are using liquified natural gas then you need a device like a heat sink to warm the fuel before it goes to the intake. you don't need a special carb you can drill and tap the carb spacer to accept the propane inlet. You can have this type of set-up cng cetified and then I think that you get some federal tax break. not to mention brezzing thro the emisions tests if you have those in your area. one more thing every one that has done this always say to run all the gas out of the bowl before kicking in the propane and vice versa. they never elaborated on what actually happened but from the look of fear on there faces I think It was'nt good.

 

Im in california, at Naval air weapons test center Point mugu.

 

ive owned a 69 ss with 400 hp 327 run off only propane. The pros are that you at about 120 to 140 octane, runs cleaner, better m.pg., never floods. cons paion to start in the winter and hard to find service stations that have it. a buddy of mine had a 72 chev 4x4 we made duel fuel. that thing screamed. the reason it ran well was because his grandfather owned a propane company and had all the resources to make it work.

 

Ahhh, California. That makes sense with emissions requirements and stuff. I am in Minnesota. At Camp Ripley we're still running quite a few old Chevy half-tons with the 305. They run the "Mogas" (unleaded fuel). Everything else is either diesel or ethanol 85. I did drive a propane powered 428 Ford Cabover that was a propane delivery truck for a local oil co-op. That thing could haul.

-Abrams

 

Yea all the propane trucks are just fleet service vehicles...mostly white. Everything else is gas or diesel just the same as yours.

 

Maybe these guys know some tricks:
http://www.alternatefuelsracing.com/
Then you might want to buy some go-fast stuff like these:
http://www.propanecarbs.com/examples.html
AL.