A way to check valve to piston clearance

[jerry clayton]

This has lots of good pictures and the write up is pretty clear about what they are doing and why/how things work-----


Engine Blueprinting: How To Check Piston-to-valve Clearance - EngineLabs

[Duece coupe]

Interesting read. Many interesting articles on that site. Thanks for posting.

[techinspector1]

Thanks Jerry, I prefer the clay method, as it covers all crank positions. The closest near miss is probably at overlap when the piston is chasing the exhaust valve back onto its seat, but depending on cam timing and phasing, the near miss could be anywhere in the overlap period, from 20 degrees before top dead center to 20 degrees after top dead center.

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[jerry clayton]

Yep Tech------people seem to be sighted in on tdc at overlap when the piston chasing the exhaust valve and intake valev chasing piston dance step . I like using clay as it will on one setup measure everything -just gotta be careful--I find many engines other people have done that have gobs of v-p but marks where outter valve has touch radius of valve notch, especially with heads with bigger valves where they have been moved


DISCLAIMER-I didn't read all thru this article, just thought it was a very good explaination and lots of good pics------I have pretty well stopped taking pics of my work as its too impossible to post them in a level that the microscopic details are visable

[40FordDeluxe]

Jerry, that's too bad you quit taking pics of your work. I really enjoyed pics from you and Pat of your great engine work!

[techinspector1]

I find many engines other people have done that have gobs of v-p but marks where outter valve has touch radius of valve notch, especially with heads with bigger valves where they have been moved

Iskenderian makes a cutter that you can rent from them in many different sizes just for that problem. You put the cutter in the valve guide and turn it with your drill motor, so that the cutter is exactly where it needs to be, unlike cutting the reliefs on a Bridgeport, where you could make a mistake.

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[jerry clayton]

Yep I have those cutters and they are nice for doing notches with short block in car- works real good with a single combustion chamber part of head--------you set it up with a stop collar on the shaft and just move from cylinder to cylinder. It is important not only get the depth right but also the location as it seems that its never centered at tdc-------