Valvetrain noise after cam swap
#12
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Join Date: Apr 2020
Location: Joshua TX
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Just rechecked with pushrod length checker. Ï believe the rocker arm geometry is throwing off my numbers when you add the desired preload with the measurement from zero lash. Zero lash is at 7.255" + target preload of .070" = 7.325" pushrod needed. It requires 1-3/8 turn on the rocker arm nut to reach 22 ft/lbs. If I drop to a 7.300" pushrod, it requires 5/8 turn on the rocker arm nut to reach 22 ft/lbs. Should I be following the 1/2 - 1 turn on the rocker arm nut ?
#16
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Ï installed 7.300" pushrods and it may have solved the problem. Ï tried the dial indicator but no luck due to the lifter being pumped up and making the valve springs collapse instead. The final rocker arm nut rotation, after torqueing, was a 7/8 turn. Will put some miles on it to see how it does.
#17
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After running the truck for 20 miles, 50 minutes, the clatter is still there but not loud. Has anybody else ran into this? Rocker arm bolt bottoms at 3/4 turn while torqued brought it to 7/8 turn. Ï hate to entertain the idea that this is normal as my stock configuration had no valvetrain noise.
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After install of cam and lifters, oil was changed after 2 warm up cycles. There is currently 20 miles or 55 minutes run time on the current oil. Ï have verified good oil flow through the drivers side pushrods. Ï will be re-checking preload on all lifters today and verifying oil flow through passenger side pushrods. The rocker arms are stock.