Flathead Cam Timing/Phasing. How did you do yours.

I know how to do cam timing no problem. The question is how to do it on the flathead as there is no adjustment on the cam gear. Flathead jack does a adjustable cam gear but it only goes up or down in 3 degree increments. What are your suggestions? I have never bothered on flatheads that i have built before but thought i would go the full hog this time round. So give us a clue on what to do.

 

Jim - never seen this discussed wrt flatheads. But as you probably know, all else being equal, advancing a cam moves the powerband down & retarding it moves it up.

Interesting topic though because there are no piston-to-valve clearances to worry about

 

Jim and Ernie
I just happen to be at the "cam timing" stage at the moment.

The only solution for "fine tuning" the timing that I have been able to dig up; is an old timer circle track racer up here used to drill the gear mounting holes oversize and use ecentric bushings along with the offset gear holes. Each change of timing meant a different set of bushings. He told me that he made the bushings in 1 deg. offsets and when used with the offset timing gear, he could get about 8 deg. range.

The one thing he stressed was, you better have a LOT of patience setting the combination up! He told me it could take 20 tries before he was satisfied.

 

Jim, what are you trying to do? Are you going racing or are you just trying to change the band around for more fun on the street? Give me some info. and maybe I can help.I've done this a couple of times.--TV

 

Dave, Thanks for the info, thought that might be the case. Surprised that no one has come up with a better way by now.

TV, I am at the stage of installing the cam after checking the cam timing to the manufacturing set figures, the cam is out by about 2 degrees (not uncommon with new cams) so i need to adjust the cam where it sits on the cam gear so i get the correct reading. The engine will be going in my gasser for street and strip action. Cheers Jim

 

Jim,

Which way is it out? What cam are you running? You could chat with the cam manufacturer & get their take on the exact effect on your engine combo...2 degrees isn't a lot...

I have also heard of using an offset crank key in a flatty, but can't remember where I heard/read that...or who makes 'em (if anyone).

 

Perhaps something like this would interest you?
A friend of mine has these done up.