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Old 03-16-2006, 07:56 PM
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adjusting cam duration by using smaller/larger timing gears

Would it be possible to adjust the duration of your camshaft by altering the diameter of the gears on your timing chain. If this is possible then why doesn't the cam manufacturers or companies who make timing chains offer different size gears. It would be like adding a bigger cam by just changing gear sizes.
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Old 03-16-2006, 08:00 PM
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Thats impossible.
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Old 03-16-2006, 08:12 PM
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The cam timing gears, chains, belts, whatevers are a 2:1 ratio. For every time the crank turns twice, the cam turns once. That is set in stone. It absolutely has to work that way because its a four-stroke engine. Altering the size of the gears would cause the cam to be out of timing the instant it began to move.
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Old 03-16-2006, 08:15 PM
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Changing duration through the gears is not the way things work. The gears are on a 2:1 ratio so that the valve timing stays true. If you changed the ratio on one gear the valve timing would then change and continue to change for each rotation. Run away valve timing...
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Old 03-16-2006, 08:16 PM
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Quote:
Originally Posted by curtis73
The cam timing gears, chains, belts, whatevers are a 2:1 ratio. For every time the crank turns twice, the cam turns once. That is set in stone. It absolutely has to work that way because its a four-stroke engine. Altering the size of the gears would cause the cam to be out of timing the instant it began to move.
haha, beat me by a couple seconds
dh
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Old 03-17-2006, 01:36 AM
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Yeah, good idea. Run 4:1 gears so your 12:1 comp drops to 6:1 with the exhaust valve opening midway through the compression stroke, you should use at least one 14/71 per cylinder and 360 psi boost.
I'm gunna tell the DEA about you. Happy smokin'.
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