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I originally set my hyd roller rockers preload doing the tightnen till I feel slight resistance on pushrod and then 1/2 turn more, then lock it down the with a cold engine method. However, I would like to know your thoughts on having the engine at a low idle with cutout donor valve covers and adjusting the rocker while running and hot? I have stud type roller rockers with a TFS stage 1 roller cam. Reason being I have very low Hg around 12, engine running a bit rough, but I have NO tick tick tick. Some have said might be the lifters are too tight?
 

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At only 1/2 turn pre load on the lifters, low vacuum is probably not valve lifter pre load caused.But....., adjusting them hot will give you a better feel for 0 pre load (starting to tick ) and at least, rule it out as the cause.Have you tried advancing the timing with a vacuum gauge attached to see if it increases ?
 

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At only 1/2 turn pre load on the lifters, low vacuum is probably not valve lifter pre load caused.But....., adjusting them hot will give you a better feel for 0 pre load (starting to tick ) and at least, rule it out as the cause.Have you tried advancing the timing with a vacuum gauge attached to see if it increases ?
Hey, thanks! Yes the vac increased 2Hg when I went from 10-12 degrees btdc to 14 deg btdc. I just went through each rocker and re-set them all to 1/4 turn past zero lash. Guess what, after I got it all back together I now have a lifter tick and the Hg's are exactly the same. No help whatsoever re-adjusting the rockers. Now I get to do all of them all over again, back to the 1/2 or 3/4 past zero lash tomorrow...uuuggghh. steaming.gif
 

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With the cam you are running, 12 inches of vacuum is normal. If you want to adjust the lifters with the engine running, loosen the rockers until they start to clatter then tighten to your choice of 1/2 to 3/4 turn and lock them down. I always tighten mine to 1/2 and have no issues.
 

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With the cam you are running, 12 inches of vacuum is normal. If you want to adjust the lifters with the engine running, loosen the rockers until they start to clatter then tighten to your choice of 1/2 to 3/4 turn and lock them down. I always tighten mine to 1/2 and have no issues.
I got all the rockers re-adjusted to 1/2 turn in, went ahead and did them with motor off, but warm. I feel like a PRO now!! The tick, tick, tick has stopped since I went back to the 1/2 turn. When I put the valve covers back on, again, I hope it will be a LONG time before they have to come back off. Thanks for your help!
John in Pensacola, FL.
 
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