We tackle valve seat replacement on two vintage Massey Harris Pony tractor engines, only to discover that our standard tooling cannot cut seats this small. The 15/16 inch diameter valve seats require ...

During one of our never-ending technical discussions, Jim Grubbs at Jim Grubbs Motorsports (JGM) suggested that we take a look at the flow difference between 30- and 45-degree valve seats. While ...

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