Flat tappet cams can be damaged by using modern engine oils that lack zinc and associated anti-scuff additives. Zinc can damage catalytic converters, so it's slowly been eliminated in modern engine ...

It is possible to run solid flat tappets on a hydraulic flat-tappet cam and even mechanical roller lifters on a hydraulic-roller cam. Putting solid lifters on a hydraulic cam will gain about 500 rpm ...

While enthusiasts can comprehend the fact that the camshaft is responsible for opening and closing the intake and exhaust valves on an LS motor, relating these events to crank position, engine ...

Despite declining sales and revenue in 2025, Harley-Davidson has been the dominant American motorcycle maker for most of its long and illustrious history. Harley has produced a succession of engines ...