Most modern multi-valve engines have a peak volumetric efficiency of around 80 percent; which leaves plenty of room for improvement. All things equal, bringing the VE up by 10 percent should yield an ...

From the October 1987 issue of HOT ROD: A Super Duty conversion kit that could give your Fiero the kind of performance its styling implied. Pontiac's Super Duty 4-cylinder engine has established a ...

From Street Stock to Winston Cup, the three most important areas for engine performance improvements are cylinder heads, valvetrains, and intake manifolds. In particular, cylinder heads affect most ...

Ferrari was so proud of its five-valve cylinder heads, it changed a naming convention that ran back over 25 years. For its previous mid-engine two-seaters, the three-digit name was derived from ...

Without question, cylinder-head porting is a science. The act of removing metal from the intake and exhaust ports to increase airflow has been used for decades, and in most cases, a skilled head ...