How tight should chains be for cam timing?

[cstreit]

Well I got the cams timed near perfectly, then installed the tensioners. I noticed that the tensioners do not pull the chains as tight as my C-clamps.

So... Should the chains be tighter than the tensioners with the motor cold and at rest, assuming that as the motor expands they will get tighter? OR, should the chains be tightened at the same tension as the tensioners at rest?

I would assume the first, otherwise what would be the point of even USING the clamps to tension the chains? (as opposed to just installing the tensioners right off the bat.)

Thanks all!

[Wayne 962]

When the engine is running, the chains are going to be tighter than they are when the engine is at rest. First of all, the engine expands when hot, up to an 1/8th of an inch from end to end. Secondly, the engine is going to be pulling the chain tight as it 'drags' the cams. The straight section of the chain needs to be perfectly tight. That is why you want as much tension on the chain as possible when timing the cams. This is covered in the cam timing section of the engine rebuild book...

-Wayne

[cstreit]

Wayne.

Thanks and that's what I assumed. For some reason I didn't see the justification in your book. Musta missed that.

For what it's worth, despite all the fretting I've heard about cam timing, your descriptions were VERY clear and easy to follow step by step. Good work!

My cams are now equal each other and only 1-2 thousandths off exact spec.