Spinning the Cam

[bobc]

Following up on my prior posts, the machine shop removed my cam towers when they worked on my head. Unfortunately, I didn't get the opportunity to spin the cam prior to this, so I don't have a baseline to determine if my cam is spinning easily enough.

I have all the rockers out and can turn (I wouldn't say spin) the cam with one hand. I can't turn it with just my fingers. I don't feel any binding, but wonder if the cam should turn easier.

Is turning by one hand about right?

Bob

[Babalouie]

When I tested mine, it was not 100% freespinning, there is a bit of drag, but you could rotate it with just 2 fingers.

[peterc]

It will/should not "spin", as in rotate freely without you turning it. The tolerances are too tight to allow for that. The way I do it is to insert the cam (well lubed!!) with the towers totally untightened. Untightened, the towers will not cause any binding when you rotate the cam. Rotating it with one hand will provide a benchmark for how easily it should rotate once the towers are torqued down.

Continue to rotate the cam as you torque down each tower one at a time. If the cam starts to turn LESS freely, then that particular tower is beginning to bind the cam. You can either loosen off that tower and try re-torquing, OR you can give the offending tower a sharp rap with a hammer, or two or three as needed, , until the cam again turns freely. Personally I prefer the second option. Loosening and retightening the tower normally yields the same results...binding. The tower will tend to reseat itself in the same position as last time, which isn't what you want. On the other hand, a good "smack" with a hammer will vibrate a semi-torqued tower into the desired position. Plus, it's much more emotionally satisfying, .

Hope this helps.

p

Repeat this with each tower, and at the end of the day your cam should be rotating as freely as it was before you began torquing.

[bobc]

So, where do you hit it with the hammer? Side to side, front to back? All of the above?

Bob

[peterc]

No, no, no! ONLY hit the towers straight down from the top, just like you were hammering a nail. Hitting them any other way could result in damage to the cam/tower. A sharp rap to the top of a semi-torqued tower will vibrate it into the correct position.

Remember, you only have to do this IF you find the cam harder to turn (bind) as you're torqueing down one of the towers.

p