valvetrain issues
Thread Starter
Drifting
Joined: Jul 2004
Posts: 1,554
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From: Wi
valvetrain issues
Today I started my valve guide seal replace process, 291 heads, and discovered all the rocker arm nuts were on upside down. Chamfer was down. Haven't looked at the right side head yet. Now, could this be one probable cause for a rocker arm(s) to wear into the stud? I know one for sure should be replaced,but at this time, probably not.
After searching and reading many discussions on stud replacement, it seems the best solution is pulling the heads. But what if only one or two(3) need replacing? I would really rather not spend a lot on these heads. Considering rebuild of motor in the future with new heads, or crate, but for now, it is what it is.
After searching and reading many discussions on stud replacement, it seems the best solution is pulling the heads. But what if only one or two(3) need replacing? I would really rather not spend a lot on these heads. Considering rebuild of motor in the future with new heads, or crate, but for now, it is what it is.
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
I suppose the upside down nuts could allow the rocker ball to **** a very small amount. Maybe just enough to allow the rocker to roll over and cut the stud. Maybe. I've never experimented like this so I don't know.
I have run engines with cut studs. If you've got 2/3's of the stud not cut, you can probably get by for a good while without problem if you don't have stout valve springs and you keep the rpm down to a reasonable level. That is, if there is no further stud cutting going on.
I get another set of rocker/ball for each stud that was cut. Used will work. Replace all the rocker nuts.
I have run engines with cut studs. If you've got 2/3's of the stud not cut, you can probably get by for a good while without problem if you don't have stout valve springs and you keep the rpm down to a reasonable level. That is, if there is no further stud cutting going on.
I get another set of rocker/ball for each stud that was cut. Used will work. Replace all the rocker nuts.
Last edited by MikeM; Nov 15, 2009 at 05:39 PM.
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
Federal-Mogul rockers if you have a stock engine.
If the stud is cut/abraided .038 and that is all, I wouldn't touch it. That's only 10% thickness of the stud. You can go to a lot of trouble to change it, maybe cause another problem and wind up netting nothing.
I'd guess if the upside down nuts were causing your problem it was probably accompanied by a noisy valve train.
If the stud is cut/abraided .038 and that is all, I wouldn't touch it. That's only 10% thickness of the stud. You can go to a lot of trouble to change it, maybe cause another problem and wind up netting nothing.
I'd guess if the upside down nuts were causing your problem it was probably accompanied by a noisy valve train.
