Measuring valve clearances is this normal???

[thewormman]

So having rebuilt and fitted the cylinder head on my KZ900 A4 I am finding that the valve clearances change every time I rotate the engine and it's driving me mad. Valve guides are new as are a couple of valves. Everything has been cleaned and cleaned again. Everything was well oiled when assembled, everything moved freely including buckets. New camshaft bearings.

So I turn the engine over, measure the clearance between cam and shim, then turn it over again, measure it again and some of them are different! How?

Is this just a case of making sure the lobe is EXACTLY opposite the shim surface as it seems like every time it is a mm or two different the measurement is different to the point of needing a different size shim!

Is this normal???

[zed1015]

Fresh cut valves and seats will initially settle even after just rotating the engine a few times so give it a few spins on the starter and re shim any that are on the tight side.
As long as you can get close to a 0.15mm feeler in the gap with the lobe 180 degrees from the bucket don't worry about the clearance you get with the cam in any other positions.
Once run for a few hundred miles just recheck the clearances and re shim any that have settled further.
After that they shouldn't change much between yearly checks.

[gray]

theoretically the clearance should be the same at all points when the cam's base circle is towards the bucket. But I always measure the clearance with the lobe pointing directly away from the bucket