One of the most common valvetrain upgrades for pushrod-style engines is roller rocker arms, which are often said to increase horsepower through reducing friction. But is it true? You’ll find out on ...

For racers, the most pressing questions we ponder late at night aren't about the meaning of life, the true meaning of beauty, or other such silliness. Yes, those things have their place, but we all ...

The typical four-stroke engine is made up of hundreds of parts. These parts are all designed and engineered to work together to make a prescribed amount of power, torque, engine longevity, and other ...

A:The Pontiac 151-inch (2.5L) L4 Iron Duke rocker arm fulcrum-to-tip distance is greater than a Chevy small-block, plus the Chevy small-block rocker has a 1.51:1 ratio, while the Pontiac uses a 1.71:1 ...