valve eats 63swc
Race Director
Joined: Nov 2000
Posts: 10,340
Likes: 664
From: Beverly Hills (Pine Ridge) Florida
However, note that stock non hardened seats (pre 1971) will last a very long time, unless used under high loads for long duration. Street engines have not seen the valve and seat damage that was once thought very likely. Boat and race engines on the other hand need the hardened seats and SS valves (or other combinations as needed, such as titanium valves and bery-copper seats, etc.). Lead additives have not been seen to be necessary for street engines.
Plasticman
Last edited by Plasticman; May 12, 2008 at 03:00 PM.
Racer
Joined: Feb 2008
Posts: 262
Likes: 0
From: Mercerville N.J.
I'm not as optomistic as Plasticman. I have no personal experience, but around here the guys with HP C-2's generally use a lead attative or stainless steel valves. I know a few guys who have had problems from not using one or the other.
The old oz. of prevention beats a lb. of cure seems relevant here.
Rob
The old oz. of prevention beats a lb. of cure seems relevant here.
Rob
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
Hardened seats aren't necessary unless you're towing a trailer all day long at 100mph or the engine is in a boat; lots of perfectly good heads have been ruined during machining for hardened seats, for no good reason. Rebuilders will always recommend it, but it isn't necessary, nor are any "lead substitute" additives (which don't have lead in them anyway - they're mostly kerosene and alcohol). 
Melting Slicks
Joined: Oct 2004
Posts: 3,345
Likes: 87
From: Northern MN
St. Jude Donor '13-'14-'15-'16-'17
Won't say my engine is super high performance but I had the hardened valve seats installed in the heads in 1979. Haven't had a problem yet. I have been running the non-ethanol fuel but it doesn't have any thing for a additive to ease seat wear. Mine valves are the stock ones so I don't see where there would ever be any problem.
Steve
Steve
