I've been told propane is hard on valves- and considering that the FE seem to have issues burning valves, what would be the best setup for building a long lasting set of FE heads? It would need hardened seats for sure, but what else? I've heard stainless valves talked about, but I've never heard anything definite about what works with propane and what doesn't.

Sam

 

Years back, dad worked for an LP gas distributor, and their entire fleet was LP fueled. He even converted his 74 390 to run on LP for several years.

At that time, sodium filled valves were pretty commonly used for LP. Hardened seats were pretty much the norm. I don't recall exactly what he called the valves, aside from the sodium filled part, also had some fancy name after the sodium filled part....

The outfit he worked for bought ford's exclusively, and always specified LP fuel systems from the factory, so the engines did not have to be torn down and modified before they were put into service. As I understand it, the move to unleaded fuel made most of the mods no longer needed, since the hardened seats were already in place.

Time has moved on, and so has technology. As such, stainless valves have pretty much taken over as the king of heat resistant valve material. Titanium is lighter, and stronger, but comes with an additional premium cost.

One thing I remember him talking about that was specific for LP-only use, is blocking the heat risers. LP boils at -44, so no heat is *typically* needed to keep it vaporized. Though it was common to have coolant running into the vaporizor, to prevent it from icing up. For LP/gas dual fuel, the heat risers could be restricted, but totally blocking them caused driveability issues in cooler temps, when using gasoline.

 

This exactly the type of info I have been looking for, thanks.

Would both the intake and exhaust valves need to be stainless? Or just the exhaust?

The rig will most likely be a dual fuel, but if I feel brave enough I might go with straight propane.

Sam

 

I would think the exhaust would be sufficient, but while you're in there......

I would certainly investigate a little further, to see if there is a better option than SS. I haven't done much keeping up with LP stuff lately, so it's possible there's a better option that I am not aware of. Might be even cheaper than the SS route, who knows?

 

Uh oh, those are some dangerous words right there! They're words I know very well, just a few months ago they resulted in $500 of drive-shaft work! Oh well, it's only money! haha

Sam