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 ...

An internal combustion engine is like a big air pump, and the more air you can get it to pump, the more torque and horsepower it will make. Things like bigger camshafts, aftermarket intakes and ...

Last month's "How It Works" story gave you the basics of the four-stroke cycle, describing the motion of the intake and exhaust valves in relation to the piston moving up and down in the cylinder.