camshaft bearing caps

I am currently restoring a 79SR and I decided to purchase a new head, because my original head had some cracks around the spark plug. My new head did not come with the cam shaft bearing caps. The service manual says that I should make sure to use matched cam shaft bearing caps with head and cam shaft. My question is do you see any issues with using my original camshaft and original camshaft bearing caps on a different head?

Other than the camshaft not being able to turn in it, nothing.

Seriously, you need the caps that came from the new head, or you have to send the head and the other caps to Rick Stetson at Harrys machine Works and get them fitted.

Jay

Jay is right, the cam bores are align bored from the factory, so each one is going to be differant, I know there are some out here that have replaced caps and made them work, but I would not try it

The cam caps used to be part of the cylinder head. The head casting was line bored and the caps cut off. This provides a pretty precise clearance for the cams. If you have a box of 100 cam caps, you will very likely be able to fit a good working set using plastigage checking their fitment one by one. If you have a manual, buy some plastigage at the autoparts store and check the clearance of your old cam caps on the new cylinder head. I suspect you will notice that they very very likely will not have the correct clearance. You can try and get the cam caps retro fitted... I think some shops can re-line bore them but you would do better to find another head; this time one that comes complete. They generally cost a tad more than the ones without cam caps bwhahahaha

Thanks very much for the input. guess I'll chalk this one up to experience, and get my old head fixed. By the way if anyone's interested, I have a head for a kz650 in excellent shape for sale!!

bison wrote:

Thanks very much for the input. guess I'll chalk this one up to experience, and get my old head fixed. By the way if anyone's interested, I have a head for a kz650 in excellent shape for sale!!

It's worth probably $5-$6 (or more) as scrap aluminum, and you don't have to mess with shipping it

Post edited by: steell, at: 2007/02/05 09:59

If you've got a really nice head there, I suggest a call to Jay's reference to see what it costs to get the caps matched up. It's not overly complicated. The caps are milled a tad on their mounting surface, mounted, and the bores are honed.

pm me on the heasd for the 650

Actually, if they are close, Stetson would only have to line hone it.

Jay

Does anybody know what the actual clearence is between the cam journal and cam caps?

The measurement that is important is the clearance between the cam bearings and cam journals. That spec is in both the Clymer and Kaw Factory Service Manual for the 903/1015. You install cams/cam caps with plastigage between the two surfaces then remove the cams and measure the plastigage.

This is bad news on the cam bearing caps. Got bike put back together and now I have to put the caps on that came with the head I bought. I used my caps on the old head because they looked in better cond. The engine has been started a few times since. Total running time approx.4to5 mins. Is it too late to replace the original caps now? 1976 KZ650. I also replaced the cams and valves from my old head. By's am I in trouble!