The Stovebolt Site Forums The Shop Area Engine Shop 235 rebuilt for unleaded?

Is there any way to tell if the head has been rebuilt for unleaded gas?
My engine in my 54 is not original. There is a tag on the side that states "REMANUFACTURED ENGINE/PRODUCTION NO./239546/REMANUFACTURER/CODE 1.

I've read a couple articles concerning this. Some say the valve seats will burn up if not rebuilt, others say its not a big concern if it is not a daily driver. Also see the parts stores sell "lead substitute". This doesn't seem economical at $7 a bottle.
So what can I expect if I drive the old gal about 50 miles a week? How long before she gets mad at me and breaks down?

I decided to run my 235 as is when leaded fuel was discontinued here. Put 120 to 140 thou. mi. on it before I pulled it for replacement. Still ran strong & steady. No problems. Thats as a daily driver where summer temps commonly exceed 115 deg. Nearest town N. is 90 mi. going W. its only 60 mi. Running a 35 yr. old big block in my 1 ton work truck, make 4 or 5 trips ea. yr. from below sea level here over a 4200 ft. mountain pass pulling a dually trailer loaded coming home with supplies, same story. Put a 292 in my car when I repl. the 235 mentioned above. About 3-4 yr. ago, avg. 10 to 12 thou. mi./yr. Same story. I quit using a well respected machinist here because he told me (1) if he did the headwork he'd have to install hard seats (2) a 292 is a poor choice for a car because 'everybody knows they're a gas hog & you can't change that'. I avg. 22.5 MPG on 200 to 300 mi. trips with my 292 powered car running 60 to 70 MPH.
Doug

This is a very timely topic for me. My engine is going under the cutter in a week or two. I'm getting conflicting recommendations on this issue and I hope more people jump in with their experiences.

Rockies54. Other than pulling the head to see if hardened seats have been installed, I don't know of a way to tell.

I agree with Doug on this subject. Leaded gas was touted to add some lubrication to the valves which was supposed to make them last longer. I maintain numerous old cars & trucks for customers that have the original engines and they run fine. Several are driven to car shows from So Cal to Reno and las Vegas.
There was a article in Vintage Truck on this subject a while back. Essentially high performance engines could have problems with excessive valve wear. Most of the early 6 cylinders don't fall into this category. If your engine is going to be rebuilt and some of the seats have excessive wear, install the hard seats, otherwise leave it alone.
Fred

I have no problems with UNLD gas nor I have I heard any problems from any members here in my local Inliners group. So I wouldn't be concerned about it.

292,s all have hardrned seats if they still have the original head. Practically every engine built from 71 on has them. If you don,t run hard the old seats will do O.k. in the other engines.

Aviation planes such as the small cessna 172 use Av-gas 100 octane low lead. I know people try to obtain this higher octane fuel for there homemade race cars. Although I don't need 100 octane particularly it is still leaded gasoline. I wonder if there is a affordable way of buying leaded gasoline such as aviation fuel.
Or maybe just substituted with it every once in a while.

I use a small amount of Marvel Mystery Oil added to the gas in my old cars,trucks and tractors. Never had a valve problem. I can buy AV-Gas from the local airport at $4.00 a gallon, but why waste the money.

The only time you'll have a problem by not installing hardened seats is if you work the engine hard for extended periods. 99.9% of drivers will never have a problem using unleaded gas. In fact there is some documentation that installing hardened seats can cause problems if the seat comes loose. I've been running unleaded in my stock head 38 with no problems. I put many thousands of unleaded miles on my old pre unleaded '70 HD without problems.

OK, it seems like the concensus is don't sweat it if everything else is nomal. The engine runs great as is, so I'd hate to disturb it.

Thanks to all!
Rick

One thing I can add to this, the lead in the gas was done to prevent knocking, particularly in high comperssion engines. Any valve lubrication was strictly a side benefit. I will say that I did have hardened seats installed in my head, along with new valves, but that had more to do with the severly burnt valve on #5. Plus it was relatively cheap from the machine shop I use, $12, valve and seat, installed.

Exactly, regardless of my signature.