The term "twin cam" is imprecise, but will normally refer to DOHC eng valves, but are necessary for more than two valves that are directly actuated (though still usually via tappets).
The term "twin cam" is imprecise. The term "twin cam" will normally refer to DOHC eng valves. The term "twin cam" are necessary for more than two valves (though still usually via tappets). These more than two valves are directly actuated.