Performance cam tappet clearance spec?

[srsupertrap]

I have always wondered why is the aftermarket cam tappet clearance (valve lash) spec different than suzuki OEM tappet clearance specification? Case in point for the GS1000 2V, Suzuki specifies a tappet clearance of .001 to .003 inches (.03 to .08 mm). The Andrews S1 cam along with every other Andrews suzuki cam manufactured specifies .004 to .006" inches of valve lash, cold. Anyone know the reason why? I have always set the S1 valve lash in the range of .004 to .006" and never had any problems. Just trying to understand the logic of the performance cam manufacturers specs. You would think suzuki would know best on a tolerance specification

Also curious what is the valve lash for Web's, Yosh Stage I or III & Mega cams?

[SqDancerLynn1]

I think it has more to do with the ramp profile of the camshaft lobe than anything else. I would go by the cam mfg specs

[Dan Ruddock]

You can always run a little tighter if the recommended is noisier than you like. Dan

[srsupertrap]

Yeah the #1 intake valve is fairly noisey but that could be the bucket though too? Not sure. So does tight valve lash equal a burnt valve because the valve has less contact or perhaps no contact with the valve seat and thus no heat transfer?

Anyone care to comment about the other cams mentioned?

[Big Jay]

I couldn't imagine .001 clearance. As soon as the motor warms up the valve would be hanging open.