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Author Topic:   Three keyway timing sets?
Eljojo
Dirt Forum Champ
Total posts: 968
posted October 06, 2005 03:59 PM  
We've all seen them, one key for 0 one for +4 and one for -4. In a discussion a few weeks ago a friend said that, because the crank and the cam travel at a 2:1 ratio, moving to a 4degree slot would only move the camshaft 2 degrees. I thought the 4 slot would move tha cam 8 degrees. Anothr opinion says it moves the cam the total 4 degrees. I guess I could play around with the gear and the degree wheel and find out..but it's soooooo much easier to ask here! Thanks! Jojo

leapinlizard
Dirt Freak

Total posts: 402
posted October 07, 2005 07:37 AM  
I measured a total of four degree's. The keyway if off 4 degree's of crank and two of cam. Degreeing a cam you always talk about crank degree's not cam degree's.

Eljojo
Dirt Forum Champ
Total posts: 968
posted October 07, 2005 09:17 AM  
So, what you are saying is that, if I have a camshaft that measures out on 108 when on the "0" keyslot, I can move it to the +4 keyslot and it will degree in at 104? (+/-)

leapinlizard
Dirt Freak

Total posts: 402
posted October 07, 2005 01:24 PM  

If you check you cam open ramp at a given lift,(normaly at .050) and the cam closing ramp, half this distance is the center line measured in degree's of crank rotation. Assuming it striaght up. If you move the crank more in the normal direction of rotation but not the cam, you've moved the centerline backwards or retarded. The opposite is true.

So if the cam was at 110 striaght up, moving the cam to 106 advances the cam +4. Moving the cam to 112 retard the cam -4.

James Ott
Dirt Maniac

Total posts: 131
posted October 30, 2005 06:00 PM  
My brand new Cloyes Says cam will be 2* advance or retard all measurements are specified in crankshaft degrees

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