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 ...

As with most things in life, it’s the details that make the difference. You might not think that a measly degree here or there could make more horsepower when it comes to a valve job, but there’s ...