[Ben M.]

Ok, fully stock '72 455 with a new Melling 068 clone cam, new Melling lifters from 2006, and stock 47 year old rocker arm & pressed in studs setup. Following the factory "torque to 20 ft-lbs and done" procedure, several cylinders after torquing the rocker nut the pushrod is super tight and will not spin, nor will the lifter. Using a fine touch to rotate the engine it hangs up and is obvious that a pushrod will likely bend if I continue to force it, so it's obviously not correct. Most of the other cylinders the lifter and pushrod spin freely and don't clatter, so their adjustment seems ok.

What's going on? Nothing in the factory service manuals I can find says anything should be off and they don't even specify to check the pushrod and lifter movement (seems ripe for bending a pushrod or wiping a cam lobe). Should I just manually take in the nut until the pushrod gets a little resistance to rotating and tighten it down another 1/4-1/2 turn like an adjustable valve train? Or am I st00pid and forgetting something simple? I can't imagine that the pushrod or lifter should bind up this much on 20 ft-lbs, but it is.

And yes, I know that "an adjustable valve train with poly locks" is a better solution and one I'd like as well but without pulling these heads off or putting $1000 into another set I have laying around, that's not in the cards at the moment so let's not have that argument. I have a set of '74 46s and 6X-8s that I can send out for valve work but I'd rather not spend the money at this time or delay the engine install another 6 months. Engine is on a stand with the valley pan off so it's easy to see what's going on, engine won't get fired up or installed in the car until I sort this out.

[ponyakr]

I suppose you could just try some sbc 3/8 adjustable nuts. These have worked on millions of sbc engines with press-in studs.

My experience is that many of the aftermarket sbc nuts will back off, even when tightened only once. But, some won't. I suppose that some grip the stud tighter than others. You can usually tell by how much effort it takes to turn them. I always bought several extra & used the tighter fitting ones.

I think that these nuts are tighter than the Pontiac nuts, simply because they are out of round, more oval shaped. Not sure of that.

Here are 4 brands.

https://www.summitracing.com/search/...=rocker%20nuts

https://www.jegs.com/i/COMP-Cams/249/1400N-1/10002/-1

https://www.jegs.com/i/PRW/228/1200246/10002/-1

Most all parts houses should have some brand in stock. I always bought from our local NAPA store. Don't have a clue which brands might be better than others.

A whole set of 16 isn't very high.

https://www.amazon.com/Comp-Cams-140.../dp/B000CIS6LU

If the Chevy nuts run out of threads, before they go down far enuff, you can just use a hardened washer under them. If you have any trouble finding them, your local Fastenal store should have 'em.

https://www.google.com/search?q=7%27...hrome&ie=UTF-8

Hey, I even used 3/8 poly locks on the screw-in bottleneck studs, on most of my Pontiac drag engines, back in the old days. Never broke a bottleneck stud. Might not be a good idea to use poly-locks on press-in studs tho.

[NeighborsComplaint]

Bottle neck studs (3/8 top/7/16 bottom with a step) are set by torgue.

Do you have bottleneck or straight 7/16 studs?

["QUICK-SILVER"]

Push rods and lifters will be tight on all valves that are open.

Tight ones and loose ones should change when you turn the engine.

Remember pressure on the push rod is one and a half times spring pressure with stock rockers. So push rods on open valves will feel pretty tight.

Clay

["QUICK-SILVER"]

Originally Posted by NeighborsComplaint

Do you have bottleneck or straight 7/16 studs?

Stock press in are bottleneck. And he did say they were torque to spec.

Clay

[77 TRASHCAN]

Well crap...
When I adjust rockers/lifters on a new engine. I am kinda paranoid about it. There's ways you can spin the engine 90 degrees 4 times and set them all accurately...I don't do it that way...
If this was my deal...I would remove all the rocker nuts, and either start at the front or rear of the engine. Put each cam lobe on its base circle (exact opposite of highest point of lift on other side of cam lobe), tighten the factory nut down to the 20 ft/PB spec.

At this point you should be able to push down on the push rod side of the rocker arm, and it should move...a little. This verifies that the plunger in the lifter is somewhere in the middle of its travel inside the lifter body.

Since you've run into this questionable situation, I'd likely do each lobe, one at a time, them remove the rocker nut, and then do next cam lobe, in order. Doing so will all you to rotate the engine easily to do each lobe, without previous adjusted lifters having to ride the new cam lobes around.

When/if you find a lifter bottomed out, you can gently rotate the crank to see what's up. Only likely things are valve spring bind or spring retainer hitting top of guide. Another is possibility of a worn valve stem catching top of guide (Shaker455 mentioned on your other thread).

I built a tempoary Pontiac 350 to go in my 77 TA in early 90's, bad thing about this is,it's still in my car...but I am working on a couple of bigger engines for it...

When I built the 350 it was to be an economy build, it mostly was but I had to buy more parts than I wanted...any who...
I had install a new cam (a Sealed Power CS641, a stock replacement type cam, which I found out later is a 066 duplicate cam) I checked it with a degree wheel, that went well. Then proceeded to install lifters, push rods and rocker arms and adjust them.

As I adjusted each lifter, I was a little bothered by the fact that no two lifters had the same plunger depth. Hmmm. I walked away from this for a day or so. Then decided I could make the calve train slightly adjustable. Even though this was essentially a stock engine ( I believe the gross valve lift is the same as a 068 cam) I wanted the valves all adjusted the same.
I bought a set of stock Chevy locking rocker arm nuts. I drilled 2-2-1/2 threads out of the bottoms of each nut. Drilled them so that the under side of the nut would fit over the bottle neck on the stock studs.
I was able to adjust all the lifters very close to the same. This engine is still in the car, valves covers have never been off since 1992. Of course this is essentially a stock 1970 350 with number 11 heads, with press in studs. The 7m5 heads should not need anything fancy, since your setup is stock also...

My next thought is wondering when you find a possible problem child lifter/lobe issue. I wonder if that lobe may correspond to one of the flat lobes???

Are you using moly paste on the lobes and lifter faces?

[455-4+1]

Use a washer on top of the rocker ball to space off the shoulder, then use 3/8" poly lock and adjust 1/8 turn from zero lash (normal lash setting process)

[Squidward]

I assume you are torquing to 20 ft-lbs with the cam lobe on the base circle, per common rocker arm torquing sequence?
http://www.pontiacstreetperformance....p/rockers.html

Are the lifters pumped up/full?

[TAQuest]

Bad valve job, valves installed too deep? Mis-matched set of push rods? I would think it's bad head work.

[77 TRASHCAN]

Originally Posted by TAQuest

Bad valve job, valves installed too deep? Mis-matched set of push rods? I would think it's bad head work.

Engine is untouched original factory build. Never been worked on.

I thought about and tried using washers on my 350. Finding a hardened washer that is 7/16 I.D. And whatever the O.D. Of the rocker ball is, was note possible when I was trying to make this deal work better...

[TAQuest]

Originally Posted by 77 TRASHCAN

Engine is untouched original factory build. Never been worked on.

If that were the case then it should just bolt together like factory.

He could lay a straight edge across the top of the valves and see if they are all the same height.
Masking the problem with poly locks is just a way around figuring out what is wrong in the first place.

[242177P]

Originally Posted by TAQuest

If that were the case then it should just bolt together like factory.

He could lay a straight edge across the top of the valves and see if they are all the same height.
Masking the problem with poly locks is just a way around figuring out what is wrong in the first place.

I don't suppose you saw the irony in this?

[TAQuest]

Originally Posted by 242177P

I don't suppose you saw the irony in this?

Yup. A smart guy learns from his mistakes. And he will go 450+ posts in a thread to figure it out. What ever it takes for things to finally make sense. When things finally make sense then he will move forward with confidence. Maybe contribute with brainstorming other's problems, paying it forward.

[242177P]

Originally Posted by TAQuest

Yup. A smart guy learns from his mistakes. And he will go 450+ posts in a thread to figure it out. What ever it takes for things to finally make sense. When things finally make sense then he will move forward with confidence. Maybe contribute with brainstorming other's problems, paying it forward.

I prefer learning from other people's mistakes, but I may have made a mistake or two myself.

[TAQuest]

Originally Posted by 242177P

I prefer learning from other people's mistakes, but I may have made a mistake or two myself.

Right. Like buggering up a thread with meaningless personal stuff.
It's about the cars, not the people.

[ponyakr]

"...Finding a hardened washer that is 7/16 I.D. And whatever the O.D. Of the rocker ball is, was note possible..."


A bench grinder will make it any OD you need. Doesn't have to be precise. Could even do it with a side grinder, or a dremel tool, or drill with a carbide burr. On my current project, I've changed the shape of washer OD, & increased the ID, to make some washers work.

So, you could either reduce the size of the OD, or increase the size of the ID, as needed.

I can't think of any reason why the correct washer & a Chevy type adjustable nut wouldn't allow for the correct adjustment.

I don't have a stock rocker ball right now that I can measure. Just for kicks, somebody post the OD of one please.

Looks like the common specs for a 7/16 SAE washer is 15/32"/.469" ID x 59/64"/.922" OD. So, if the OD is so big that it would rub the rocker, it would need to be ground down some.

https://www.amazon.com/Grade-Hardene...re-bullets-btf

https://www.ebay.com/itm/Extra-Thick....c100677.m4598

https://www.fastenal.com/products/details/1133816

A 3/8" ID SAE washer is 13/32"/.40625" ID x 13/16"/.8125" OD. So, if the OD of this size will work, you could just make the ID bigger, to fit the stud.

[TAQuest]

Butler sells the washers for heads that have been worked on and don't fit the original geometry.

[ponyakr]

Originally Posted by TAQuest

Butler sells the washers for heads that have been worked on and don't fit the original geometry.

Those are listed as Pioneer # PF-494. You can buy 50 for less than $15, on Amazon & Ebay.

https://www.amazon.com/Pioneer-PF494.../dp/B0049JI7J4

Haven'y found the OD size yet. Anybody know ? Has anybody measured the OD of a rocker ball yet ?

Here's a few washers at Summit.

https://www.summitracing.com/search/...3%2B4294867355

If anybody wants a really small OD 7/16" washer, he can buy some rod bolt washers.

https://www.jegs.com/i/ARP/070/200-8501/10002/-1

[TAQuest]

Standard hard washer then. No need to customize it.

["QUICK-SILVER"]

Originally Posted by Ben M.

Ok, fully stock '72 455 with a new Melling 068 clone cam, new Melling lifters from 2006, and stock 47 year old rocker arm & pressed in studs setup. Following the factory "torque to 20 ft-lbs and done" procedure, several cylinders after torquing the rocker nut the pushrod is super tight and will not spin, nor will the lifter. Using a fine touch to rotate the engine it hangs up and is obvious that a pushrod will likely bend if I continue to force it, so it's obviously not correct. Most of the other cylinders the lifter and pushrod spin freely and don't clatter, so their adjustment seems ok.

Ben,
When you say it hangs up are you thinking piston to valve contact? Or something else?

Unless you swapped in a or some extra long pushrods, piston to valve contact doesn't happen with a 7M5 headed 455 with a 068 cam.
Don't know exactly how much over but I know .500" intake valve lift doesn't hit with a piston at TDC. Add to that, the only time valves are open at TDC is during overlap when valves are just barely open. With a intake valve open .500" you can turn the crank to put a timing chain on and the valve doesn't hit.

Tight pushrods is normal when valves are open. Even after sitting a while, if the valve is open further than plunger travel in the lifter, the pushrod will still be tight. So unless you did put in a or a few extra long pushrods I'd have to say there's nothing wrong with valve adjustment. That's given some do feel like they are suppose to.

Something else...
Does the crank bump to a stop when you turn it or just get harder to turn?
Bump to a stop: I'd be afraid something went down an intake port and is laying on top of a piston. Unless you've got a wrench or socket missing that might have fell down to the crank while the cam was out.

Springy feeling when it comes to a stop, like a pushrod fixing to bend, I'd be looking for a stuck valve or valve spring binding up for some reason.

Just harder to turn might be normal feeling you get when the cam raises a lifter and starts opening a valve.

Before I went crazy and tried to force it to turn...I'd turn the crank the other way and see what happens.

Clay