How crooked is too crooked!?

[crazy_caseys_customs]

Hoping that post title gets this some eyes. I’ve had issue after issue with my latest build, and I think it’s time for a new machine shop, but I’m at the point where I just don’t want to tear everything apart again.

I’ve got two rocker studs that are visibly not straight. They’re all in alignment running down the line (lengthwise with the heads), but I’ve got two that are canted out, the worst of which is about 0.040” out at the end of the stud. I first noticed this by the fact that the rocker tip was a little off center on the valve stem. I was able to cheat the adjustment on the guide plate, basically splitting the difference between the pair. I’ve yet to read the wear pattern with dye-chem.

I think I could throw an adjustable pair of guide plates on this motor and dial it in pretty close. I could also tear the whole thing down again, and have those two studs repaired. I’d be out at least a couple hundred bucks, plus a new pair of head gaskets. My question is whether or not I’m overcomplicating things? This is a very mild build, though I’d like it to last.

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[cgarb]

Maybe try replacing the studs? Its possible they could either be bent or not machined straight with the threads on the other side. I would start there first.

[crazy_caseys_customs]

Already swapped a couple around with no change. They’re brand new ARP’s, so the likelihood of them being bent is pretty minimal anyway.

FWIW, these heads were purchased used, and they had what looked like some serious miles on them, I’m assuming, without any major issues. I’m only bagging on the machine shop because I asked them to check these heads out for me, and they didn’t catch this misalignment.

[tresi]

Most likely someone tapped them by hand

[crazy_caseys_customs]

Most likely someone tapped them by hand

If they did, they did a pretty decent job. I’ve heard of hand jobs being way off, and the worst of these is barely more than a 32nd. And the bosses were milled.

I’m sure the guy before me threw the heads together without checking this stuff. And he probably slept better at night, too.

I guess I need to check the pattern on the valve tip, and go from there...

[Geoff2]

The rocker on the left is very noticeably crooked. Not good. Both sides of the trunnion brg should share the load equally, but in this case, one side will be more heavily loaded.

[BillK]

That end one does look pretty bad. Problem is it will be a pain to fix it. Probably will have to put it in a mill and try to drill that hole straight and then put a Timesert or helicoil in it.

I agree with the others that it needs to be fixed. I would be more concerned with the roller tip hitting the valve crooked. I don't think the bearing in the rocker will be affected that much.

[tenxal]

Yeah, it's not perfect.

But the thing is...the 'fix' may open a bigger can of worms than you have now. If it's .040 off at the end of the stud, it's likely less than half of that where the trunnion operates. And with any play in the trunnion, the roller tip will pretty well square up on the valve tip under running conditions.

Also, try a few wraps of Teflon tape around the stud threads to see if that squares up the stud in the tapped hole.

[427dart]

That means the hex head of the stud isn't squarely tightend down which would allow some movement of the stud while engine is running.

[Newold1]

Remove the valve springs and check the straightness and alignments of valve stems, guides, tops of rocker stands, valve spring pockets. Check those two pushrods on a piece of glass for straightness.Check for valve stem wear and valve guide wear. You should try to relevel the stand tops to the deck and then install a good stud girdle to hold straighter alignments on the rocker studs as a group.

I also suspect as others here that the threading on those two stands was not straight from day one.

[pamotorman]

if the head spot face is correct just retap the threads with a rag around the tap so it taps oversize and the head spot face should set the stud straight. install with red lock tite

[SupStk]

Also check the poli-lock. Seen some where the threaded hole isn't straight with the body. Watch as threading it on the stud, any runout is very visible.

[CGT]

Also check the poli-lock. Seen some where the threaded hole isn't straight with the body. Watch as threading it on the stud, any runout is very visible.

I have seen this as well. I thought my mind was playing tricks on me at first

[piston guy]

It needs to be corrected to straight up or replace it. Heli coil or time sert would work. As is it will side load the guide, guide plate and pushrod. Looks like a regular 289 head , easy to replace. IIRC , Pioneer used to sell a screw in stud with the bottom thread of 1/2" rather than the far more common 7/16ths thread. Just a thought.

[MadBill]

Since it's a mild build, I'm the guy that would consider a sharp whack with a FBH to stand the stud up straight...