Has anyone ever tried propane injection to boost the octane rating and run more compression in a 400? The ricers use it to up octane and run more boost, but I dont see why it couldn't be used to run 10 to 1 or better on 93 octane in a v-8. Maybe I am way off, but it's something I've been thinking about. Seems like it could be pretty simple to get some kind of system in place....

 

Do you mean that you want to run gas ( petrol ) and then inject propane as an octane booster.

Or do you want to run straight propane injection.

Ray71.

 

inject the propane as an octane booster, I don't think I want to run entirely propane

 

Here in Australia most V8 owners run propane because gas is about $4.00 a gallon, and we have some of the best propane systems you will find
but I don't think it's ever been used as an octane booter.

Thats not to say it won't work, but I think it would take a fairly complex system to make it run.

If you go straight propane you can run about 11 to 1 compression rate.

Ray71.

 

Ray71- Seeing as you are in Australia would it be possible for you to supply some of us fellow enthusiasts with your native cleveland heads????? Maybe we could supply you with things that we have plenty of too!!!

 

Sure, How many sets would you like, and is it the 302 closed chamber heads that you want.
How would we go with inport duty's, I wonder if we do a swap would it be duty free.

Ray71.

 

I've seen it used as an octane booster in 4 cylinder turbo engines. I don't know a whole lot about the specifics, but they run like 1 part propane to 4 parts gasoline, and it lets them run a good bit more boost. Its injected into the throttle body before the injectors and the turbo.

What kind of fuel economy do you get from running straight propane? I know propane prices have gone up lately, does anyone know if it's still cheaper than gasoline? I would imagine that it's surely cheaper than race gas or AVgas, which I am also considering, since I won't be driving it much, and I live blocks from an airport.

 

If the motor is set up and tuned to run on only propane it's about the same fuel economy as gasoline.

Ray71.

 

As I understand it, to run on propane requires hardened valve seats and stainless valves (at least on the exhaust side). How can I tell if my heads came with the hardened seats? Besides the propane fuel delivery sytems and the valves, what other modifications are required? What size tank is needed? And isn't it almost like driving around in a giant bomb? Cause seems like a getting rear-ended could be downright unhealthy if you have a propane tank in your trunk......

 

that aint a problem once i get my 302C heads done
dsc has the things for 300 a set clean and fluxed look into the shipping and duties and you will apreate dennis's price

i was thinking about after finishing my heads/intake/carb/cam/headers(fenderwell)/and the rest of the exaust

breaking in the new parts? running a dyno base line then a quick REAL RICH rejet and change the fuel for say 3 or 5 gallons of 4oz klotz nitro in premium unleaded sause

might melt my block but sure gonna be fun

well if your running stock type 2 piece valves and can pull them we all know what happens when the 2nd part breaks lose
and while your in there...might as well put seats in
i know the aussies casting is rather tough but it shall be done as i rather not wreck it
ah it will be sporting stylish undercut and swirlpolished hard chome(if i recall) heattreated single peice SS they look marvolous

 

Getting rearended with a gas tank has also proven fatal. I've been running propane / gas (dual fuel) on my 87 F150 300 I6 for 5 years and its still running like new after over 150,000 miles.

 

Tank size is about 30 gals (rear tank). Had to remove the spare to front of the truck.

 

OK, let's say that a person has an engine built up as a "race" engine- intake, headers, higher compression and so on. how will that engine perform on propane as compared to race fuel, and what is the compression ratio limit of propane?????