Chev 292 cid - Unleaded Fuel?

Run it on unleaded, or get one of the (popular?) lead substitutes?

Yes, it will run on unleaded fuel. You haven't told us what usage it'll see. If it's just going to be a daily driver around town, to and from work, with a dab of highway once in a while, it'll probably last as close to forever as an inline six can. If you're going to pull it or use it for a dragster, you might ask yourself what you're doing with that kind of engine in that kind of usage.

Lead used to provide a little cushioning and lubrication between the valves and seats. Without it, if the engine is running hard and hot, it may need a valve job a little sooner. That's when you can consider whether a simple valve job, replacing the valves and seats with units designed for no-lead fuel, or replacing the head makes economic sense. The odds are that nothing past replacing the valves and seats could possibly pay for itself, and I'm inclined to doubt the valves and seats are going to be justified.

Enjoy it! Those were fun trucks.

What other vehicles were these engines in? Maybe I might go for a bone yard motor that ran on unleaded.

I'm afraid I haven't yet understood your goal in trying to make the engine somehow agree to run on unleaded fuel. You also haven't told us the condition of the engine now.

I don't believe you're going to gain by spending any serious amount of money in a quest for either extended engine life or increased dependability--unless it needs an overhaul now. Otherwise, it'll run until something goes wrong or something wears out--and on a truck this old, it isn't even terribly likely that it'll be because of unleaded fuel. There are quite a few other places to cause trouble, such as transmission, clutch, rear end, drive shaft, body rust, front end...

When something finally does go wrong, decide whether to make some changes, based on its anticipated service and how many miles you plan to put on it. Until then, drive it and enjoy the reduced fouling of the spark plugs and the fact you're putting less lead in the atmosphere for your grandchildren to breathe.

What I wil be doing is fiitting an LPG system to the vehicle, for best results an unleaded engine is the best candidate or at a modified head. This way you me and your grandchildren will breath easier. :)

Now I'm getting an entirely different picture. I couldn't imagine why somebody would want to update a forty year-old engine to use hauling firewood.

I don't think I had heard that an unleaded engine is better for LPG. Do you happen to know why? I would have guessed higher compression engines would be more efficient, since the octane rating of propane is considerably above unleaded gas. So much for guessing.

Have a good one.

BTW, get somebody who knows A LOT about propane conversions to do it. If you don't know why, look up a car wash explosion in Springfield, Missouri, in 1981. One little shortcut...

If Wikipedia is to be believed, the 292 was produced 1963-1990.

So after all that can you help me with my original question?

--If not can i get an unleaded head and valve unit or crate motor from somewhere.

Where have you tried? When I was looking for the details of the 292, I found several online ads for rebuilt engines. On the other hand, if you're willing to swap the engine, have you investigated swapping in a different engine, maybe a 350 V8? I don't know what you're going to be using this for, so don't know whether that would be better or not as good for your purposes. There should be 350s of all types and descriptions in boneyards all across the country.

Given the shipping weight of a rebuilt engine, I'd certainly consider somebody close by.

Yeah OK

I've got several inline 6's in various old chevy trucks. I have a older pre oil pump 292 in a 51. It was designed for the larger trucks (1 ton and higher). think the first was around 1941. It is a splash oiler and you don't want that. the 292 is very desireable now for old half ton trucks because it has more torque and HP therefore can run better around 50 mph here in the Ozarks. I use unleaded in all my trucks and have had no problems. If you hot rod (increase compression, air and fuel volume) your truck and run the engine temp up you will have valve and seat problems. If you run it around town as it was originally designed (about 45 mph or less) it will be fine. My wife complains that the old inline 6 engines ping on unleaded. Fortunately I can't hear that well. there is a great paperpack book out about inline 6 chevy engines. It tells about all the casting numbers and the differences in heads available. If you still what a good inline six build for unleaded it will probably be the 250 workhorse.

Propane was a common fuel for tractors in the 40's and 50's before diesel. they don't have a problem running any hotter than gasoline engines. I think Ford made a propane tractors as early as 1938 so they were using the same old valves they were using in their gas 4 cyl's. you may even be able to convert easily using a tractor carb. I think you will find an easy conversion using tractor technology from the 50's.

How about having hardened seats installed in the head?

That and stainless steel valves, should be close to bullet proof.

I hope this helps.

RK