valve lash K1103 cam

[Hello]

1981 350 corvette. K1103 camshaft from summit .440 and .460 lift overlap is 110 same as stock. My question is on the valve lash is 1 complete turn too much?! Car will not idle and timing is correct and low manifold vacuum with metal grayish grit in the oil. I pulled the oil cap and while #7 exhaust was open I tried to push on # 7 intake would not move at all. OEM 1.5 rockers in engine. I have kicked myself I knew 1 turn was too much!!

 

[Hib Halverson]

First, if this camshaft is a hydraulic, it has no lash.

The adjustment is the amount of plunger preload which is applied to the lifters.

Also, my guess is the 110 is not overlap but the lobe separtion angle. The overlap is probably far less than 110 deg.

Typically 1/2-a full turn of preload is what you want but you need to consult the lifter maker to know for sure.

If you have metallic grayish grit in the oil, that is typical of camshaft failure. If a camshaft is going to fail, it's far more likely to fail soon after installation. There are a number of reasons why that happens, but rather than dwelling on that now, what you need to do is address the grayish grit in the oil.

I'd get the intake off and the lifters out and inspect all cam lobes for wear. If you find a bad one and the amount of wear is sigificant, you'll need to rebuild the engine.