Thread: 441 cyl heads
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Old 01-08-2011, 07:23 PM   #4
X-TECH MAN
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Smile Re: 441 cyl heads

Quote:
Originally Posted by Rick Shirey View Post
Several years ago I purchased a set of 441 cyl heads from a super stock racer who guaranteed me that were not cracked and I thought I asked if they were super stock legal. I just recently started to disassemble them and noticed that the intake valves measure at 2.02 and not 1.94. My question is, can I have all the seats replaced in order to go back to the legal valve size of 1.94? Thanks in advance for any and all input.
Yes....Its legal to replace the seats. NHRA OK'ed this a few years ago and IHRA has allowed it almost forever to save rare hard to get casting from becoming junk.
If possable find a shop that uses an adjustable cutter for the seat and guide machine such as a K.O. Lee machine so you can use a little more interfearence (approx .004) fit for the seat ring than the non adjustable standard cutters so they won't come lose and fall out from the hi RPM use. . Make sure the shop uses a sealer/locking liquid compound and freeze the seat rigs before installing them in a warm/hot head. With this method I never had a failure in over 40 years of replacing seats. Use a little more interfearence fit when installing them in alum. heads.
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