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 ...

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.

Worldwide, Honda enthusiasts invest hundreds, if not thousands of dollars on their powerplants to extract the utmost in power and reliability. Whether they opt to keep their Honda naturally aspirated, ...