Originally Posted by Liquid_02

Agreed. Wear should be dead center on a proper length rod. I just used an adjustable chevy pushrod to figure out my length.

Also, that is not the proper way to check PTV, that doesn't really tell you too much... Other than it hits or doesn't hit your clay, very crude, very in-efficient.

Proper way to check PTV with head set on with the gasket, bolts with a decent amount of pressure, not enough to crush and waste your gasket if you have a problem, torquing them is fine aswell, I always do, as you don't have to remove the head if there's issues, it's a cam/rocker issue at this point.

Install a pair of checker springs on an intake and exhaust with a solid lifter. Install pushrod and rocker on valves with checker springs. Place dial indicator on top of retainer, keeping it as square as possible to valve movement. Bring the piston to the top in that cylinder, now push down on the valve and watch the dial indicator. How ever far down the valve goes is your PTV clearance at that point in the stroke, now rotate engine back and forward a bit, and check your PTV clearance throughout the degrees of rotation. Rotate engine 180* and check the other valve using the same procedure.

Doing this will give you a NUMBER, much MUCH more important than any piece of clay will show you. Especially when considering valve float, and with the clay you have no idea at which point the valve is actually closest to the piston. For all you know it's closest when the piston is still coming up when you use clay, which is a definate NONO. I can guarantee to you that you've never seen an engine shop use clay to check PTV, as it is a more lengthy way to do it, and no where near as accurate. Installing a set of springs only take a couple minutes, setting up the dial indicator another minute. Much faster than installing and removing the head and smearing the piston with clay.

Originally Posted by FivePointOhh

im using the shortest rod i could find. its a 6.100 and if you look at the wear pattern now that it has been in use...its exactly dead center. i think in the picture with the sharpie mark it still had some of the original measurement wear off in it. i dunno. but its correct...trust me



its not a perfect write up, but its a good reference that answers a lot of common questions.