Camshafts are simple devices, but important ones. Modern engines can have one or more intake and exhaust valves, and it's the camshaft's job to open valves precisely as the engine runs, supplying the ...

General Motors has spent decades refining overhead-valve V8s while much of the industry pivoted to dual overhead cam designs, turbocharging, and downsized blocks. I set out to understand why Chevrolet ...

Modern engines take advantage of roller tappets, which allow for more aggressive cam profiles, and they require less ZDDP in the oil, because the rollers reduce friction between the cam and tappet.