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Lead also helps with valve seats lasting longer. Automakers switched to hardened valve seats in the 70's when lead was taken out of gas.
by bluedino 5y ago
Lead also helps with valve seats lasting longer. Automakers switched to hardened valve seats in the 70's when lead was taken out of gas.
- jabl 5y agoAFAIU, expensive (or read: less cost-sensitive) engines designed for operating at close to rated power for extended times, like airplane engines, have used hardened valve seats since the 1920'ies or so.
- bluedino 5y agoLikely - I can't remember if it's Ford or Chevrolet (or both) but their big-block engines used hardened seats from the start, only the small-blocks had to switch. And some airplane engines still use leaded gas.