[QUOTE=Cbrinson47;636898]
Quote:
Originally Posted by Mike Pearson
Years back I won class at the gators and went through tear down. One of my intake valves measured .001 under the low limit. The valve was badly tuliped. I was tossed for the event and had to show up at the next event with the head off and have the valve size checked before I could race. I was also placed on 6 mos. tech probation. That infraction was considered minor. FYI I put new valves in the heads for the next race and the car picked up a tenth.
Did you know that the factory tolerance on a micrometer, Dial indicator, or dial caliper is plus or minus .001. I know this because I used to calibrate precision tools for the Dept. of the Navy. They should be checked with "GAGE BLOCKS" a least once a year. Tools being treated to rough treatment as in running all over the U.S. should be certified at least several times a year. Do you really think most tools being used by the NHRA tech. dept. have been certified?
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Wesley was the tech guy during that tear down. When he found the valve just under the low limit he told me if I could find another caliper that measured the valve one thousanth bigger he would pass it. We checked the valve with 3 different calipers and they all measured the same. After I got home and fixed the heads I got to thinking I should have heated the valve to the temperature that it gets to when the engine is running and it might have grown .001 and passed.