Does anyone have any experience with converting the 4.9L to propane? I'm considering changing my 92 F-150, 4.9L and am looking for advice on the subject. Like: Problems to look out for, Whose kit to buy, etc. Thanks

 

there were propane 4.9s fromt the factory, a haynes or chilton manual might help to figure out what you will need to do.

 

here is some info i found not for 4.9L though.
http://www.txpropane.com/2006propane...emproducts.pdf

 

Not sure where you're from but all the local farmers in my area use propane powered 300s on their well pumps for irrigation. You might be able to check a local O'Reilly's, Autozone, or whatever your favorite parts store is and find a pretty reliable setup. I'm not sure what prices would be like though. As for converting an entire truck to propane you might also consider getting either a large propane tank to go in the bed or possibly use smaller interchangeable cylinders like they have on forklifts. Because if you run out of 'gas' then it's kind of hard to just go and fill up again.

 

It would be tough... but I'd try and find a "boneyard" 300 that came as LPG from the factory. There weren't many of these ever put on the road, most LPG 300's went into industrial applications like forklifts, pumps, and generators.

The main engine specific things you'll need will be the "carb", pressure regulator ,and its associated plumbing. You can find "universal" aftermarket carbs but it's very hard to get them tuned for proper performance and economy on a road vehicle. It's fairly easy for a stationary generator that simply has to spin at the same speed all the time, but not when you have constantly varying load and speed. The simple open loop systems tend to dump in excess fuel when coasting/ slowing down.

To get the most out of the LPG you'll also need to do some block modifications. Since LPG is lower calorie than gasoline [30% lower by liquid volume] but much higher in effective octane rating [110], you're wasting serious power and efficiency if running stock low compression pistons. You'd see a 10%-15% drop in horsepower/ torque, and not get super mileage. LPG is 110 octane equivelant, so you can run 10.5:1 CR and still be safe. It's hard to get that on a 300 without custom pistons, but if you use off the shelf 8.8:1 pistons and deck the block you should be able to see a 9.5:1 CR, close to 10:1 if you shave the head too.

Properly built an LPG engine will give just as much power as a gasoline burner and be very efficient. Since you're not paying road tax on the propane the cost savings will also add up. It's also much cleaner, so you can go 10k-15k miles between oil changes easily.

 

Thanks for the info