496 shortblock is assembled, cam Overlap question
Thread Starter
Instructor
Joined: Feb 2001
Posts: 217
Likes: 1
From: Suwanee GA
496 shortblock is assembled, cam Overlap question
The cam is degreed and checks out fine. If I want to calculate the overlap, is it just the difference in degrees between the Exhaust opening and the Intake closing? Is it measured at .050?
Btw, shortblock is looking good. We may have to trim two studs to get the oil pan to fit, but all other clearances checking out fine.
Btw, shortblock is looking good. We may have to trim two studs to get the oil pan to fit, but all other clearances checking out fine.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
It depends on what you want to do with the number. To me, an overlap number only has meaning when developed from .006" lift, durations. If you are comparing overlap numbers from other cams that are generated at .050" lift, then that is the way to go.
RACE ON!!!
RACE ON!!!
Burning Brakes
Joined: Nov 2001
Posts: 1,189
Likes: 2
From: Austin TX
Actually, it's the time, in crankshaft degrees, between when the intake opens and the exhaust closes. On a sample cam card I happen to have handy, the intake opens at 21 BTDC and the exhaust closes at 20 ATDC, both at .006". Since one event ocurrs before, and the other after, top dead center, you can simply add the two numbers together and in this example this cam has 41 degrees of overlap, measured at .006"
Dan
Dan
