I degreed the cam in a 383 sbc using both the intake centerline method and the duration at .050 method.

Using the IC method I found the cam to be installed at 106º,which is exactly where it should be.

Without moving anything and using the duration at .050 method,I am 2º off on the valve events per the cam card. What's the deal with that?

Hydraulic roller 236/242 286/294 110 LSA 106 IC

Thanks
Lonnie

I have gotten into this also , I found it a measurment loss with my tools, and dial indicators and timing chain. I took Harolds advice just to install his cam straight up and call it good.

I have gotten into this also , I found it a measurment loss with my tools, and dial indicators and timing chain.

This is what I was thinking. I have the basic "cheapo" small diameter Summit degree wheel that could be a factor.

Thanks for the feedback
Lonnie

HERE (http://www.chevelles.com/forums/showthread.php?p=1068467&highlight=dirty+method#post1068467) is where Harold describes his "Quick and Dirty" method of verifying if the cam is installed correctly.

your cam lobe is assymetrical. That means its profile is different on the opening side than the ex side. I use the max lift method at .002" (yes two ) on each side of max lift.

HERE (http://www.chevelles.com/forums/showthread.php?p=1068467&highlight=dirty+method#post1068467) is where Harold describes his "Quick and Dirty" method of verifying if the cam is installed correctly.

What is he talking about in step #4? "an identical mark 2º counterclockwise" Would that be for a crank gear that has three keyways?

your cam lobe is assymetrical. That means its profile is different on the opening side than the ex side. I use the max lift method at .002" (yes two ) on each side of max lift.

Would you explain this method please?

What is he talking about in step #4? "an identical mark 2º counterclockwise" Would that be for a crank gear that has three keyways?

Yes.

Once you set the degree wheel on the crank and find true piston TDC put your dial indicator on the #1 int lobe and rotate the crank until the cam reaches max lift. Zero your dial indicator while its still on max lift. Now I back the engine (counterclockwise) to about .020 the come back towards TDC again (clockwise) till I get .002 before TDC. Mark the degree wheel. Then rotate past max lift and stop on .002 after max lift and again mark the wheel. True lobe center is the point between the two marks.For example if befroe max lift is 96 and after max lift is 116, then the centerline will be 106.This link explains it also but uses .050 on each side of max lift. Some lobes are so assymetrical that it could also throw off true tdc. >002 is safe.
http://www.reedcams.com/degreeing.htm