Checking Valve Clearance

[OneBad91]

Can someone help me by telling me the step by step process of checking valve clearance. thanks

[Idhomustang]

Ok,

Pull the cylinder heads and place a small piece of wax paper over the number one piston, passengerside front. Place about a 1/4 thick piece of modeling clay or playdough over the valve notches located in the piston if it is slightly oversized thats ok. You can roll it flat and 1/4 thick with a round piece of tubing between two pieces of wax paper of saran wrap, aluminum foil if needed. Do not place the clay on top of the piston without something protecting the cylinder and piston top, or you will end up with clay in a ring groove.. yuck!

Replace head and tighten head bolts 20 of so foot pounds, with cam installed and using a the proper technique adjust the valves one number one cylinder. Using manufactures specs should feel a slight tension on the pushrod. (note you should have first pumped up you lifters with a pump-up oil can using the proper grade and make of oil.) If the engine doesn't rotate stop and pull the head and look at the clay, if the valve has pushed all the way through the clay, you will need a smaller cam.

Now slowly rotate the engine, 360 degrees, back to tdc, two full revolutions. Now pull the rockers back off of the number one cylinder and and remove the modeling clay, using a sharp knife cut a cross section out of the ex and intake impressed into the clay. Using a digital or dial caliper mic the thickness if you are.100 or more your good to go. If you are less then .080 on both intake and ex, you might consider notching the valves. Remember two that you will be adding the compressed thickness of a head gasket back into the equation around .040 or so. So if you had .100 without the gasket you now have .140 with the gasket. Every manufactures gaskets compress differently, the numbers are posted on summits site and jegs, these are typical values to be expected.

I made my own tools for this using old intake and ex valve and a piece of tool steel welded and reshaped and sharpen, works good. I also recut by hand using a dial indicator to cut the right depth.

If you have to recut your balance factors will change and your engine might vibrate, maybe not badly, in that case you might consider a new cam with a lower lift number. I usually dummy fit the engine first before anything is balanced. Deck clearances and all of that are finished and valve clearances are checked before the engine is balanced that way everything is perfect. Usually cams under or around .500 work great with only an occasional need for change. You should remember most stock ford heads will only handle .500 lift with stock springs and retainers.



Clean the cylinder, I usually check corners, just to make sure number 1 and 8 cylinders most only check number one.

Mac