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 ...

I bought a 1969 Chevrolet Chevelle SS 396 recently and want to know if unleaded gas will harm my engine. Also, will using regular unleaded instead of high-octane unleaded hurt? I’d rather use the less ...

A small gap with big importance in the performance and health of an engine - here's everything you need to know.

Time was when a valve job was done with some valve-grinding compound and a vacuum cup on a stick. But no more. Today's high performance engines require the same machining precision in the valves that ...