Dec 5, 2013 #21 kb1982 Active Member Joined Aug 10, 2013 Messages 591 Reaction score 4 Location Kentucky Heads designed for use with leaded fuels didnt have hardened valve seats. The lead in the fuel acted as a lubricant for the seats, which slowed down accelerated wearing.
Heads designed for use with leaded fuels didnt have hardened valve seats. The lead in the fuel acted as a lubricant for the seats, which slowed down accelerated wearing.