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Discussion Starter #1
Never had this problem B4 so any ideas would be appreciated! 291 heads have been redone with screw in studs & roller tip rockers, locking adjust nuts & double valve springs (Crane), Summit hydraulic cam/lifters [email protected] but when I set the valve lash cold, it runs ok for a few miles then I hear clacking. So, pulled the valve covers & set them hot by backing off until the clacking starts easing them until it stops then 1/2 turn down. By the time I get to the #7 # 1 is clacking again! Did it again & again & seemed ok then after 100 miles clacking & ROUGH idle again! Whats up???
 

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:mad:




Sounds like the camshaft was NOT properly broke in and MAY be going bad.


:(
 

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I would not start the motor anymore until the lifters are taken out and inspected for ware or anything else out of the norm.
 

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Discussion Starter #5
Deuce said:
:mad:
No, thats not the problem as the cam & lifters were broken in with the original build & reinstalled when I put the new (to me) heads on.




Sounds like the camshaft was NOT properly broke in and MAY be going bad.


:(
 

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when you primed the oil pump before starting it after working on it each time,did it have good oil pres..your're sure there is oil all the way up to the lifters.
 

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you can sit and speculate all day long about what's going on. First thing to do is yank the intake and check your lifter bottoms. IF you're not surepost pictures of all 16 on here. Make sure you keep track of where all the lifters and pushrods go!

K
 

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Discussion Starter #9
I've done all these suggestions B4 posting but still problematic! Got really focused on individual changes & find that there are only three that keep changing. Has anyone had problems with Summit lifters?? I can set these 3 the same as the other 13 but they change and clack after a turn around the block! The rest are fine!!
 

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Summit Cam & Lifters

al37ford said:
Has anyone had problems with Summit lifters??
Yes!:smash:

Pretty sure the cams are ground by Crane, but not sure about the lifters. Two cams in two different engines and both had problems. Maybe it was me :rolleyes:, but I will not buy another Summit cam & lifter set.

I went hydraulic roller in my last engine to avoid the hassle of flat tappet problems :thumbup: Good luck, Ed www.edgesz28.com
 

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Discussion Starter #12
killerformula said:
i've run them and never had a problem. LIfters are supposed to turn in the block.

K
No, no I meant driving the car around the block and these three start clicking again. Now I'm wondering about replacing the whole set with newbies from Crane or Comp as I guess i can lube the lobes with cam break in lube leaving the cam in place as I don't want to take 1/2 the front of car apart to pull the cam.
 

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Personally, I would not put new lifters on a used cam. I am sure it has been done countless times successfully; but to me, it is not worth the chance.

My last cam had two lifters that were not spinning. They had not wiped at the time I pulled the intake and inspected the lifters, but the tell-tale signs were there. Below is a picture of one, you can clearly see that the lifter was not rotating. Note - the bottom was smooth, but there is reflection at one corner, so it looks worse than it really was.

I would pull the intake and inspect the lifters as killerformula suggested earlier. If you find any problems, I would replace the cam and lifters, and consider a hydraulic roller. Yes it is costly, but think of the money and aggravation saved by having to replace another flat tappet cam (if you have another problem). And more importantly, the piece of mind knowing the lifters (and/or cam) are not the problem.

Good luck, Ed. www.edgesz28.com

 
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