I have a 1973 FX Shovelhead.

In case you havent been following the other thread, I'm currently putting this motor back together after finding a few problems.

I installed the cam as the book said - aligned with the timing gear and breather gear. But I noticed, when turning, that the cam gear turns once and the other two turn twice, since they are smaller. The cam at this point could turn 180 and align back up with the other two smaller gears

My question is... Can the cam be 180 out and still run? Does it matter?
I have already had this motor running with the cam in this way. The only changes I made were changing the pistons and rings and valve work.

My thinking is that it doesnt matter. As long as they are aligned at one point. Until the cam is in, the pistons are just up and down, not - fuel intake stroke - comp. stroke - power stroke - exh. stroke

Please correct me if Im wrong. I really dont want to take this thing apart again. The book really isnt clear.

Thanks
Lee

 

The cam cannot be 180 out. It rotates at half the speed of the crankshaft, so the timing mark will be 180 out on every other revolution of the crank.

 

It can, however, be a tooth or two off in either direction. Some tuners actually do this on purpose depending on their setup. I'll admit, I've put motors together, had them run worse than I expected, and ended up pulling the cam cover to make sure I lined up the cam, pinion, and breather gears correctly. Some shops even make their wrenches take a picture of the alignment before buttoning them up so there is no question down the road...

 

I always install my cam 360 degrees out, they run best that way.

 

The one thing about shovel owners - they have to have a sense of humor.

 

That's because they ( we ) have to!!!

 

well a sense of humor and dirty fingernails.

 

And an optimistic can-do attitude.

 

I've had brand new cams out of the box as much 30 degrees off time before , Andrews shovel cams are notorious for being out 3 out of 5 when I check them .