Hey all,

We got my new custom Comp billet cam in. Out of curiosity, my builder decided to profile it just to gain further insight into roller lobe profiles. All of his circle track stuff is flat tappet.
He did the first 4 lobes, and on the 4th, began to see >.002" of runout in the base circle. And saw that the closing ramp on that lobe had some funnies....it was different than the other 3.
Next test is to see if the center cam journals show the runout.
Is this normal?
How much base circle runout should be tolerated?
If the center journals show even greater runout, the cam will go back for another.
Maybe some day I'll get this thing on the dyno.....maybe.

Ron

Originally posted by Ron454:
Hey all,

We got my new custom Comp billet cam in. Out of curiosity, my builder decided to profile it just to gain further insight into roller lobe profiles. All of his circle track stuff is flat tappet.
He did the first 4 lobes, and on the 4th, began to see >.002" of runout in the base circle. And saw that the closing ramp on that lobe had some funnies....it was different than the other 3.
Next test is to see if the center cam journals show the runout.
Is this normal?
How much base circle runout should be tolerated?
If the center journals show even greater runout, the cam will go back for another.
Maybe some day I'll get this thing on the dyno.....maybe.

Ron =
Ron,
Not unusual at all to see runout in a cam & if a custom it very probably did not leave comp that way. ;)
I have gotten them .006" out before & I just straighten them.
In reality you could put the thing in & never have a problem as you are literally putting tons of spring pressure on it & it will be fine, I just feel better if it is within a thou or so of straight before I put it in.

Thanks Mike,
We will see what further investigation reveals.
My guy also said this could have happened in shipping. But if so, it should have been boxed better.
Ron

Originally posted by Ron454:
Thanks Mike,
We will see what further investigation reveals.
My guy also said this could have happened in shipping. But if so, it should have been boxed better.
Ron I don't think you can box it good enough sometimes,, I have gotten two cams over the last few years in two pieces from a well known delivery service graemlins/sad.gif