I have an 03 5.4 250 and am looking for a way to stop supporting foreign countries, I already pay taxes here. My question is, has anybody run a propane setup on their truck. I know Roush sells a kit for the 150's and a very few kits for the Super Duty's. I would like to know mileage, performance, modifications needed. I've already located a few filling stations around me and it's very cheap compared to gas. Any insite on this would be great.

 

keep in mind that you will burn about 30% - 50% more propane to get the same BTU's as gasoline.

your mileage will be less, but the only way to compare two different fuels is miles/dollar.

if you can get it cheap then go for it, as long as you realize that your range will be limited by either your tank or your wallet.
it will get real old having to fill up your propane tank at a home and garden store if you cant find a good filling station that sells in bulk when you are on a trip.

i nearly bought a propane caprice that was an ex taxi cab.
i just couldnt justify having such limited range on my primary vehicle.

as far as performance, it all depends on the jetting, and mixture.
since not much r&d has been done on propane fueled IC engines, you will have to dig through a lot of 'myths' but logic says that as long as you dont run around at full throttle all the time, where the extra BTU's needed will overwhelm your heads, intake, exhaust, ect, you should expect similar performance.

i want to say that you could probably advance your timing some and maybe even increase compression, but thats something you would have to play with once you get it running stable.

a turbo would be fun just to say you have a turbocharged propane engine lol. not too many of them runnin around


let us know how it turns out

 

You can switch between propane and unleaded so range or fuel availability isn't a concern. You can get a good size propane tank though so he should be able to go quite a ways on LP.

I've never seen a superduty on LP but I'm sure they've gotten even better than when I was driving them. My dad put his work trucks on them b/c he drove a lot of miles, we had a tank at home w/ a wet leg so fuel was cheap. Won't comment on the payment of road tax though. Last one he converted was a 95 F150 and it was selectable between unleaded and LP. Seemed to like to start better on gas, especially in winter but ran fine on propane. I'm sure they've improved the technology since then. I drove his old work truck, an 84 F150 - it was only propane and it ran really well. LP burns really clean so spark plugs last forever. Every time gas gets really high I think about dragging that thing out of the weeds and getting it going again. One of these days I'm going to do it.

Have to run the numbers. If you don't have a tank at home you'll have to pay road tax and propane can get expensive per gallon. Not sure what it would cost to convert one now either. Basically I think you would have to drive a lot of miles for it to pay.

Let us know if you decide to do it, I'm curious what it would cost to do today.

 

Isn't propane refined from petroleum?

 

I know its not LP but I've witnessed an installation of one of these very low cost CNG kits on a 4.6L f150 and it works beautifully.

http://www.ewsews.com/index.html

 

Sure is - so it generally goes up as oil goes up. However, and this is the key right now, it's more of a direct substitute for natural gas than unleaded or diesel so the price has to stay competitive w/ that, and natural gas is relatively cheap right now. A few years ago when natural gas was 3x what is now and oil was $150/bbl, propane was pushing $3/gal in my area and that's w/out any road tax. Price is also depended on location - there's a major nationwide distribution terminal 60mi from me so it's generally a bit cheaper here.

 

That's what I thought. When the OP said he didn't want to support foreign countries buying their oil and refining to gas and wanted to convert to propane power, I wondered how that would achieve his goal.

Now, if he converted to CNG, then yes.

 

I had a early 90's 454 chevy truck converted to propane. It was done for a fleet company to try and stabilize fuel cost and prevent employees from stealing gas for personal cars. That thing ran just fine, but it had zero power. It used about 20% more propane than gas, and had about 1/3 less power. I would imagine that the later port injected setups, combined with better ecu's would move the performance gap closer, bit you will never have the same performance as a like for like gas engine. If you rebuilt an engine for propane, with say 12:1 compression and a special cam, it would run alot better due to the higher octane (or turbocharging as mentioned earlier).
Other benefits are running at almost any angle, and very clean oil. Plus, when you run out, the vehicle will still run, but at a very low engine speed, sometimes enough to get to a filling station.
problems can be had with exhaust valves and seats from the lack of any lubricity in the fuel.

 

Propane is around 110 octane rating, making it ideal for use on either turbocharged or high-compression engines. A propane mixer will operate fine in any position so it's not like a carb in that respect.
There is definitely a fair amount of power loss in dual-fuel applications (like LPG+gas) but an engine set up specifically for LPG only will make a lot more power than a dual-fuel setup. Timing can be advanced as well, but on distributorless ignition systems that can be difficult.
If you want to turbocharge a propane engine, it works very well since you can blow through a propane mixer, as it works on pressure differential and not manifold pressure.

About the oil staying clean, that is a bit of a myth. Despite the fact that it stays clean, it does break down and you'll wreck your engine if you leave the same oil in for too long. I used to work in an engine rebuilding shop and saw the results of bad maintenance several times.

 

A converted gasoline engine will never make more power set up to run just LPG than gasoline unless the engine was rebuilt to run specifically on LPG. Advancing the timing worked well on older engines, but will not provide any significant gains on a modern cylinder head, especially a modular. Chamber design and quench play more of a roll in determining total timing advance neccessary for peak power. Also, propanes octane when measured the same as gasoline (r+m/2) is more like 105 octane.

 

we did a add on lp injection on our diesel to improve mpg. and yes it did improve mgp a little but not enough to cover the cost of the lp.