Right church, wrong pew.

Your friends correct if it were an overhead valve design with pushrods. If you don't trim the pushrods when you skim or shave the head, you get bad rocker arm angles.

An overhead camshaft engine doesn't have that problem. They get retarded timing, but that's a seperate issue.

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So I finally got around to checking the valve adjusters, because they were starting to make some noise again. It's only been about 2500 miles since I put the new EB adjusters in. The #4 intake adjuster was the loud one. It was worn down quite a bit. I haven't had a chance to take a picture of it yet, but it looked similar to the one in the middle from the first post in this thread, except even more worn.

There is plenty of oil up there, so I don't think lubrication is the problem. But, it does look like alignment of the rocker arms could be an issue. On the #4 intake for example, the adjuster stud is misaligned with the valve by 1/3 the diameter of the stud, towards the back of the engine. Is it possible to get washers/shims to rebuild the rocker assembly and get the rockers aligned properly? Or, does anyone know of a good source for a new rocker assembly? The #4 intake is the worst, but a couple others are visibly out of alignment also.

Thanks.

if the rocker arm tower dowells werent transfered over when the head was replaced the valve adjusters wont line up right. i made that mistake b/c i thought they were on the new head. luckily i didnt put the engine in the truck yet.

I haven't checked the dowels, I wasn't aware of that before. But, all of the rockers and cam lobes line up really well, so I wouldn't think it would be a major problem like that. I'll check that this weekend though to make sure.

Here is the worn out #4 intake stud (after ~2500 miles):


It's not an hourglass shape. It's actually worn quite flat, you can feel it pretty easily. Plus, you can see there is some pitting. It only really started making a lot of noise over the last 200 miles or so, so it's not like it was really loose for 2500 miles. It was pretty tight and quiet until recently. ANy ideas what could cause this?

Has anybody seen this happen before? Engnbldr? I don't doubt the quality of the studs at all, but I would think something serious would be wrong for it to get like this. I don't think lubrication is a problem. After reading around some more, it doesn't even sound like the alignment is a problem. All of the rockers lign up very well with the cam lobes, it's just that a few of them don't line up with the valve tips that well. IN another thread engnbldr mentioned that as long as the studs don;t walk off the valve tips then it should be fine, and there's no way mine are that far off.

Any ideas? I'd really prefer to not have to replace a stud every 2500 miles.

Looks like a victim of Variable Lash Adjustment Syndromes to me. <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> LOL

Seriously now, you say it was #4....which happens to tighten up clearance as the engine comes up to temperature. Just so happens #1,2 & 3 tend to slacken some what. You also mentioned it was tight to begin with...add this to the heat factor and you get a moooshed adjusting screw tip.

If your adjusters arent centered over the valve tip, they will walk off as the valve goes through its complete motion. Best way to check alignment is to pull the adjuster completly and look down the rocker hole...the valve stem tip should be all you see...no retainer. If they are misaligned it could be due to missing alinment dowels for the rocker stands, worm spacers and lateral springs on the shafts...or a rocker assembly that was assembled out of order.

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />

>>>*From the pic I will bet the valve tippet has damage. If so, this creates a high pressure wear point and accounts for the wear pattern being flat instead of hourglass shaped.

Only one thing to do and you will hate this. It is valve job time, there is no fix from the outside I know of. While in there, check the sides of the rocker arms for wear, this is one source of misalignment. Most of the assemblies have some misalighnment, the description here sounds excessive to me...*EB

Thanks for the replies guys. I was worried that it might require more extensive work... but I guess that's always a worry.

So, let's say I pull the valve cover off today, take out the adjuster stud, then climb over and really shove my eyeball right down almost onto the valve stem, and yep, I find that it looks to be a bit chewed up. That means I'd need a new set of valves at a minimum, right? I'd prolly go for the stock replacements from EB, which would run me about $60 it looks like. Would I have to have any work done to the head (I know I might find other problems while in there, but assuming it's just a valve tip problem) ? I've heard that you need to get some polishing compound and work the valves in to the head to seat them, but is that it?

Or.... would I be better off in the long run to get a new StreetRV head and get some better power out of her while I'm at it? I really don't have a lot of money to dump into the engine, and I'm happy with the power now, and I just want a reliable daily driver. But, I don't have a garage or covered workspace, and with snow coming soon, it's be nice to have a new head all ready, so I'd just need to slap the rocker assembly and cam on and a new headgasket and be done with it. I know i'd need to make sure the rockers are okay, but they line up well with the cam lobes, and it doesn;t look like any of the springs are digging into the rockers or anything, so I'm hoping it's just a buggered up valve tip. I'll get in there and take some photos this weekend though and post on here after.

Thanks again for the help.

>>>*Heck, if you are happy with the power now, no sense in dropping more bucks to upgrade. Most do that when they find the head they have is going to need extensive work, I agree, we have done rebuilds that end up costing about the same as replacing.

A good machine shop might be able to lightly surface the valve tips, then machine the seats and valve faces to spec. If so, it's a cheap repair. Of course you could hand lap them, I quit doing that in about 1964 because even then we ended up with a too wide seat and heat transfer concerns.

But if in pretty good shape, no reason why not. If so, then have the valves faced and topped, the margin thickness checked, then use the nice clean valve face to lap the seat....*EB