Help! Pushrods not staying adjusted?
Thread Starter
Racer
Joined: Oct 2010
Posts: 474
Likes: 0
From: Bishop CA
Help! Pushrods not staying adjusted?
After installing new aluminum heads I put in new hardened pushrods. A builder checked the length. I adjusted them by starting with #1 cylinder on tdc. We then followed the correct sequence for each cylinder. They keep coming out of adjustment. I read with the info on the heads from Brodix and they said to put a Loctite on each stud to keep nuts from backing off. These are the original nuts and rockers. Do these stock nuts have something in them like aircraft nuts to keep them from loosening. Could they be worn and should I try new nuts. Thanks for all the help Guys.
Burning Brakes
Joined: Sep 2009
Posts: 1,124
Likes: 140
From: Western New York
You said these are the original nuts and rockers. If that's the case and you've taken them off and reinstalled them more than once, then it's time to throw them out. Not the rockers, just the nuts. They won't hold an adjustment if you've removed them and put them on a new set of heads. The studs the nuts are going on may just be a bit smaller than the original studs, so the nuts won't hold. Spend a few more bucks and buy yourself some new nuts.(I didn't mean that the way it sounds) I'd get the ones that have a lock screw in the center that you tighten after the adjustment. Good luck!
Duane
Duane
Safety Car
Joined: Oct 2004
Posts: 3,923
Likes: 733
From: Youngstown Ohio
The original adjusting nuts were really not meant to be readjusted many times....after a few times, they have a tendency to slowly loosen even if you really crank 'em down. Get yourself a new set of polylocks, which have a nut that locks the adjustment in place. Also a thought, since you have new heads and pushrods, new rockers (perhaps roller tips or better to upgrade) would be a good idea.
Thread Starter
Racer
Joined: Oct 2010
Posts: 474
Likes: 0
From: Bishop CA
You said these are the original nuts and rockers. If that's the case and you've taken them off and reinstalled them more than once, then it's time to throw them out. Not the rockers, just the nuts. They won't hold an adjustment if you've removed them and put them on a new set of heads. The studs the nuts are going on may just be a bit smaller than the original studs, so the nuts won't hold. Spend a few more bucks and buy yourself some new nuts.(I didn't mean that the way it sounds) I'd get the ones that have a lock screw in the center that you tighten after the adjustment. Good luck!
Duane
Duane
Thread Starter
Racer
Joined: Oct 2010
Posts: 474
Likes: 0
From: Bishop CA
The original adjusting nuts were really not meant to be readjusted many times....after a few times, they have a tendency to slowly loosen even if you really crank 'em down. Get yourself a new set of polylocks, which have a nut that locks the adjustment in place. Also a thought, since you have new heads and pushrods, new rockers (perhaps roller tips or better to upgrade) would be a good idea.
Safety Car
Joined: Oct 2004
Posts: 3,923
Likes: 733
From: Youngstown Ohio
....More accurate ratio to give the best performance from your cam; (stock rockers are usually closer to 1.4 than the advertised 1.5 ratio).
Roller tips, or better yet roller rockers, have less friction.....less wear and couple more horsepower for your engine.
If you want to splurge for aluminum rockers, you also get the benefit of a lighter, easier revving drivetrain.
Also, you can get a set of higher ratio rockers for the same price which increases valve lift; slightly better performance from your cam.
Roller tips, or better yet roller rockers, have less friction.....less wear and couple more horsepower for your engine.
If you want to splurge for aluminum rockers, you also get the benefit of a lighter, easier revving drivetrain.
Also, you can get a set of higher ratio rockers for the same price which increases valve lift; slightly better performance from your cam.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
Another thing to consider is the type of nut's. I've built a few motor's with three piece rocker nut's having an allen jam screw on the top. These aren't moving, and wish I could tell you where I got them from. Really don't think this is a rare item though, and probably worth doing if pulling the cover's and adjusting everything again.
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Advanced
Joined: Apr 2011
Posts: 67
Likes: 12
From: Montgomery IL
If you go with a poly lock where there is a set screw that bears down on the top of the stud to lock the nut itself down, make sure you are using high quality rocker studs that have the tops machined down flat. I have seen many low cost studs uneven on the top which gives little surface area for the set screw to lock on.
Melting Slicks
Joined: Aug 2008
Posts: 2,200
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From: Lehigh county Pennsylvania