General Motors sees a future for engines with overhead valves, a technology most automakers have abandoned in favor of overhead camshafts. GM will introduce a new family of overhead-valve (OHV) V-6s ...

General Motors Corp. sees a future for engines with overhead valves, a technology most automakers have abandoned in favor of overhead camshafts. GM will introduce a family of overhead-valve V-6 ...

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 ...

Add Yahoo as a preferred source to see more of our stories on Google. Camshafts are simple devices, but important ones. Modern engines can have one or more intake and exhaust valves, and it's the ...

Adjusting overhead valves on heavy-duty ­diesels is a routine maintenance item subject to benign neglect in many of today’s fleets. The hardware that links the camshaft to the valves and some ...

Desmodromic valvetrains allow for higher revs without needing to worry about valve float. So why do automakers not often use ...

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 ...

It seems, for the modern American production car. that the 'L' head engine is a thing of the past. Present design trends indicate that the few remaining flathead engines now in production will be ...