what is a cam?
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Joined: Aug 2002
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From: Saskatchewan
what is a cam?
a cam or camshaft is what opens the valves in side the combustion chamber, without one you would have no horse power as the engine will not run, hope it clears some of the mud out of ur eyes
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Joined: Apr 2002
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what is a cam?
The cam has a bunch of egg shaped lobes on it. The lobes or rather the off-center shape of them is what opens and closes the valves.
On an overhead cam engine, I beleive the cam lobes press directly against the end of the valve stem causing the valve to open and close.
On a conventional engine where the cam is mounted down indside the engine, the connection is made through lifters, push rods and then rocker arms - simply mechanical connections to get to the end of the valve stems.
The shape of these lobes dictate how soon each valve opens, how high it opens (with the rocker arms as well), how long it stays open, when it closes and how quickly it closes.
Overlap is the amount of time (measured in degrees of engine rotation, actually) that both the intake and exhuast valves are open at the same time.
By playing with all of the factors mentioned in the last two sentences, power is gained or lost.
This is a very simplified generalization, but I'm sure that's what you wanted.
Regards,
On an overhead cam engine, I beleive the cam lobes press directly against the end of the valve stem causing the valve to open and close.
On a conventional engine where the cam is mounted down indside the engine, the connection is made through lifters, push rods and then rocker arms - simply mechanical connections to get to the end of the valve stems.
The shape of these lobes dictate how soon each valve opens, how high it opens (with the rocker arms as well), how long it stays open, when it closes and how quickly it closes.
Overlap is the amount of time (measured in degrees of engine rotation, actually) that both the intake and exhuast valves are open at the same time.
By playing with all of the factors mentioned in the last two sentences, power is gained or lost.
This is a very simplified generalization, but I'm sure that's what you wanted.
Regards,
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