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.

The idle air control valve (IACV) is a device attached to the throttle body that helps keep the engine of a vehicle running without throttle input, such as when the car is idling in traffic or parked ...

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 ...