VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Hardened Valve Seats

I recently bought a complete original 216 engine removed from a 1940 1/2 ton pickup, which I intend to rebuild and install in my 1940 1/2 ton pickup. Given today's fuels, is it necessary or recommended to replace the original valve seats with hardened seats? I intend to drive the truck on road trips, probably putting on at least 2500 miles per year.

If hardened seats are recommended, can a typical engine rebuilder supply the seats or will I have to locate the seats and supply them to the rebuilder?

Mark Yeamans
VCCA #35724

Don't waste your money. You do not need hardened valve seats. Your 216 will run just fine on unleaded gas with the stock valve seats.

Agreed. I've heard far more about issues arising from putting in hardened seats than from not.

I have a 39 that had hardened seats when I purchased it. The motor was running like new until a hardened seat came loose and burned the number 6 cylinder exhaust valve. Fortunately there was no other damage. It is presently in the shop having an oversize hardened seat installed.

i asked the same question a few years ago. my 216 was rebuilt with stock parts. today it is still running strong, no smoke. i too thought that i should run leaded gas. but chevgene told me that to just run a good grade of unleaded and everything will be ok.

I have been running unleaded gas in my '51 Chevy with stock valve seats for about 22 years now and the car loves it! In that time I have had absolutely no problems whatsoever.

I have a similar problem. I will soon start doing the mechanical restoration on my 41 CN. I have a rebuilt 216 engine that I bought in Nashville, TN. I was told it was a machine shop rebuild with a brand new head. It is a long block and all buttoned up and ready to be installed. I recently blew the 216 in my 41 coupe and had an older shade tree engine that was overhauled by my dad some 20 plus years ago. I decided to take the head off and have hardened seats put in. My machine shop guy said that if I was going to drive it much I should spend the bucks. I had new valves put in and the head and manifolds planed to the tune of $500 plus. After reading the opinions here, I think I'll just skip the hardeners and drive it till it breaks. BTW the old engine's fiber cam gear gave up the ghost. I was racing a moped at the time. Dang! Comments?

My last post didn't make much sense. I was referring to the TN rebuild when I made the comment putting the engine without the hardeners. I did it on the coupe.

By the way I would like to get to the other things available here on the site but I can't. That's because I had such a hard time getting through the very unfriendly pre-register rigamaroll that I failed to include the second part of the registering process on my last attempt, that lo and behold went through. Now I can't fix it. Can anyone help me get this worked out. My membership number is S 006073. Thanks, Charlie

Chevgene, what did you mean when you advised KWchevy1940 to use a good grade of gasoline? Thanks, Charlie

I don't recall ever saying a "good grade of gas".....just plain old every day 87 octane (85 at high altitudes) is what I would recommend.
I do feel that hardened seats are unnecessary and do not have them in my cars. The only time I would recommend having hardenend seats installed would be if the valve seats were ground several times and the valves are sinking deeper into the heads.
Indication of a problem of valve seat recession due to the use of unleaded gas would be the decrease of the valve/rocker arm clearance after many miles. The evidence of this happening would be less valve noise and a rough idle when engine is hot.
I drive may cars long distances at interstate speeds and have never had a problem.
I still say the old leaded gas often caused exhaust valves to "burn" due to the lead deposits on the seats and preventing the valve from closing tightly. I remember cleaning the deposits from the valves on a wire wheel bench grinder years a go.
If I had a choice between leaded and un-leaded as I would choose the un-leaded every time.

Thanks for all the replies. The reason I asked is that I had a really nice '36 Buick Special Sport Coupe a couple years ago, and after driving about 1500 miles or so, the valve clearance had decreased to the point that it was affecting engine performance. The only thing I could figure that was happening was just a Chevgene desribed--the valves were receeding into the seats.

I have put about 12,000 miles on the 216 motor that is currently in my 40 pickup, which has a 48 lower end with the original 40 head and manifolds. The bulk of those miles are highway miles at 50 mph, which translates to about 2400 rpm from the engine. The engine runs strong, with no problems or symptoms of valve issues. Valve clearances hold very steady, with only occaisonal adjusting required. When I rebuild the replacement 216 motor, I'm going to take everyone's advise and pass on the hardened seats.

Hardened valve seats were more necessary with leaded fuel. When the 216 was built the only fuel available (standard down here) was very similar to todays unleaded so hardened seats should not be needed.
Tony

Still running my '40 216 with unhardened seats. It now has 414,000 miles. I was driving it long before unleaded gas became the standard. Unleaded gas is great! It eliminated the between overhaul valve jobs (about every 40,000 miles) caused by usually one burnt valve. I now run from overhaul to overhaul (usually about 110,000 miles) without pulling the head for a valve job. The unleaded gas also keeps my oil from looking like something that should be used for road repair. Keep using those unhardened seats with unleaded gas. And don't waste your money on lead additives.

I took the head off of my 1940 216 without hardened seats. After 20,000 miles I did notice a little too much wear on one seat, but nothing too major. The seat was fixed and the car was returned to service. Still no hardened seats. I run the the cheapest gas around and the 216 runs great.....especially at 60 miles per hour. Why I have been known to drive 613 miles in one day from Galena, Illinois to home.

dtm

That 1940 he has is almost perfect