Quote:
Originally Posted by r lane
Years ago a rebuilt engine with a substantial clicking noise. We had combined diff pistons, heads etc. Pulled it down and saw nothing, at least at first. We were looking for something glaring due to the noise. What we finally discovered was barely a fingernail shaped crescent shadow on the exhaust valve pocket shoulder. Doesn't take much to make a racket. Bob
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Much like the faint trace you can see when a valve diameter is too tight in the valve pocket. Generally, there is only a .040 clearance between the valve and pocket. With a 47 mm valve (as stated) in a piston designed for a 46mm valve the clearance may be too small.