About This Quiz
The air and fuel mixtures that power your car's engine are controlled by valves that open and shut. The essential camshaft rotates and instigates the valve movement. But how exactly does this crucial engine part work? See how well you can shift mental gears and take the camshaft quiz.The key parts of any camshaft are the lobes. As the camshaft spins, the lobes open and close the intake and exhaust valves in time with the motion of the piston.
The most common types of camshafts are the single overhead cam, the double overhead cam and the pushrod.
Cams are driven by the crankshaft via a belt or chain (called the timing belt or timing chain) in single and double overhead cam engines.
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A double overhead cam engine has two cams per head, so inline engines have two cams and V engines have four.
Like single overhead cam and double overhead cam engines, the valves in a pushrod engine are located in the head, above the cylinder. The key difference is that the camshaft on a pushrod engine is located inside the engine block, rather than in the head.
VTEC (Variable Valve Timing and Lift Electronic Control) is an electronic and mechanical system in some Honda engines that allows the engine to have multiple camshafts.
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Some cars use a device that can advance valve timing. This doesn't keep the valves open longer; but it does open them sooner. This is done by rotating the camshaft ahead a few degrees.
The motion of the camshaft controls the action of the engine valves, which then regulates the amount of the air/fuel mixture that powers the engine.
The cam actuates rocker arms that press down and open the valves. Springs return the valves to their closed position.
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