Time was when a valve job was done with some valve-grinding compound and a vacuum cup on a stick. But no more. Today's high performance engines require the same machining precision in the valves that ...

The choke valve in an engine's carburetor, whether it's a Holley carburetor or another brand, helps a cold engine start by restricting some of the airflow into it. When the engine is cold, the choke ...

General Motors’ all-new 3.9L V6 has been honored with a Breakthrough Technology award by Popular Mechanics for its innovative use of variable valve timing in an overhead valve engine. For ages GM has ...

Valves control how air and fuel get in and how exhaust gets out, and theoretically, more of them should translate to better airflow and more power. Before the 80s, two or three valves per cylinder was ...

Virtually all current production-based cylinder heads incorporate a cross-flow design with intake ports (Photo B) located on one side of the head and exhaust ports (Photo C) on the opposite side. Some ...

Automobiles were still in their relative infancy in 1905, but they had been growing more popular for years. There was a problem, though: they were extremely noisy. One cause of the noise were the ...