Can a resident expert give me some reasons why one would, or would not use oversized valves when replacing valve train components on an 8ba. I figure the more discussion I can generate regarding the subject the better off I'll be 'cause I am in the dark. Also any thoughts on 1949-50 vs 1950-53 valves would be a bonus. Regards, Carl
Why Oversized Valves ?
- Thread starter 1950F1
- Start date
Karl Wolf
Well-known member
For a street engine, what you have when you enlarge valves, is shrouding by the cyl head... You could replace 1.5" valves with 1.6", but In my opinion, you don't get that much. I put 1.5 Chev exhaust valves in with a hot rod cam and like it, and yes, it's just my opinion... Karl
Ol' Ron
Well-known member
Two questions, the late 51-3 valves are shorter and have valve rotators. This is due to the fact that hardened seats were eliminated.
49 to early 51 had hardened seats in the ex only, truck and commercial engines had hardened seats in both int& ex.
As for oversize valves the 1.6 Chev valve is a common replacement, some feel this improves performance? I use the 1.6 valve to repair the seat of a non-hardened seat. Using the slightly valve exposes good material in the block for sealing. I also Knurl the guide for .001-0005 stem clearance, this provides better stem lubrication and less oil consumption.. I don't use the rubber guide seals just coat the guide with RTV when installing. Hope this helps.
49 to early 51 had hardened seats in the ex only, truck and commercial engines had hardened seats in both int& ex.
As for oversize valves the 1.6 Chev valve is a common replacement, some feel this improves performance? I use the 1.6 valve to repair the seat of a non-hardened seat. Using the slightly valve exposes good material in the block for sealing. I also Knurl the guide for .001-0005 stem clearance, this provides better stem lubrication and less oil consumption.. I don't use the rubber guide seals just coat the guide with RTV when installing. Hope this helps.