Checking valve clearances with the head off?

bountyhunter wrote:

polkat wrote:

bountyhunter, let me see if I follow you. The clearance between the cam bearing journals and the bearing area is compressed downward by the chain tension, slightly changing the readings?

Does on mine, I have two shims that will change about .002 by releasing chain tension. I checked cam journal clearance and they are in spec.

I've been having this problem. Which is the right way to do it, then? With the chain tensioner on or off? A difference of .002" is pretty significant...

staniel wrote:

bountyhunter wrote:

polkat wrote:

bountyhunter, let me see if I follow you. The clearance between the cam bearing journals and the bearing area is compressed downward by the chain tension, slightly changing the readings?

Does on mine, I have two shims that will change about .002 by releasing chain tension. I checked cam journal clearance and they are in spec.

I've been having this problem. Which is the right way to do it, then? With the chain tensioner on or off? A difference of .002" is pretty significant...

I do the check with the chain slack pulled tight because that's the way it runs.

fast_johnny wrote:

I remember a shop in San Francisco, KC Engineering I think, where the owner was a KZ nut and he did a great job of bench shimming. He used an old KZ cam that was cut in half so he could bolt it in and check clearances without having to compress the valve springs on the open valves. I am about to do the same with the old cams that came out of my KZ as I won't be needing them anymore...

Interesting. I have noticed the spring pressure from the other side will lift the cam in the journals and affect the clearance a bit.

bountyhunter wrote:

fast_johnny wrote:

I remember a shop in San Francisco, KC Engineering I think, where the owner was a KZ nut and he did a great job of bench shimming. He used an old KZ cam that was cut in half so he could bolt it in and check clearances without having to compress the valve springs on the open valves. I am about to do the same with the old cams that came out of my KZ as I won't be needing them anymore...

Interesting. I have noticed the spring pressure from the other side will lift the cam in the journals and affect the clearance a bit.

Yes it can but it's not enough to matter. Lobe directly away on all valves works fine.

I find the easiest way to rotate the cam is to mount a cam sprocket bolt in the cam and use a 10 mm wrench.

Just a note-
Always becareful with cam bolts. The torque is like #10.
So treat them with respect.