Cam Timing On 502
 

I changed my timing chain set from the cheap stock set to a roller set, when i degreed the cam it was retarded in the straight up( zero) position. the 4 degree key got it to within 1 degree of what the cam spec reccomended. It seems that I lost 200-300 rpms. Has any one retarded their cam to get more rpms? should I put it back like it was? Thanks for the input.

When you say 4 degrees, is that 4 degrees off on centerline or 4 degrees off on Intake opening?

Duration method of degreeing the camshaft in is the best way. Crane gives an indepth instruction on how to do this. Reason duration method is better, with an asymetrical cam lobe you have different opening and closing rates, so with centerline method you can be off as much as 6 degrees.

Chris

That was off centerline. Sorry about the lack of info. I guess what I needed to know did mercruiser t-chain have built in retard or was the cam ground that way.

Well retading a cam shaft will move your HP up the rpm band, this can be some help if you dont have a large duration cam shaft for top end in a boat. Sorry the answer does nt match the question. Rag's