Nater_Potater
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- Apr 7, 2013
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Possibly, but, from what I know (questionable information), induction hardening was done on cast iron heads beginning in the early 70's (or thereabouts), since it could be done in situ without the added expense of machining for seat inserts (like the Norton head). This gave us hardened exhaust seats in the parent metal. Once changing over from iron to aluminum, the seats can be made out of anything you like to reduce VSR, since you are now forced to go the route of machining for the individual seats.Were exhaust valve seats fitted at the Norton-Villiers factory induction hardened?