[Rich-Tripower]

The #8 exhaust rocker stud has partially pulled out of the head. It is 1/8" taller than the rest. Is there any way to press it back into the head with the head/engine still in the car?

[Tom Vaught]

Originally Posted by Rich-Tripower

The #8 exhaust rocker stud has partially pulled out of the head. It is 1/8" taller than the rest. Is there any way to press it back into the head with the head/engine still in the car?

I have driven them back to the normal (equal) height with a OLD Poly Lock (screwed on and locked to protect the threads as much as possible) by hitting the Poly Lock nut with a BIG Hammer. Deal is the stud will pull again down the road. Sometimes the "adjustment" will last for several years and other times the stud will move again in a short period of time.
No way of knowing. Go for it and see what happens.

Tom V.

[Rich-Tripower]

How big of a hammer are we talking? I have a small but heavy copper hammer and I have a brass punch. I can get the sledge out of the shed if I need to.....

[Tom Vaught]

Normal 2 or 2.5 pound head steel hammer will work (Like this one)

http://www.zoro.com/g/00059781/k-G10...FWELMgodNz4AzA

Tom V.

[Rich-Tripower]

Hammer and brass punch and I was able to get it back in place. Not entirely convinced it will stay put. What is the long-term solution? Pull the stud and drive in one with a slightly tighter friction fit? Pin the stud? Do they drive into the water jacket like on a Chevy head?

[Baron Von Zeppelin]

good grief

you'll be a 389 wizard after this engine is de-bugged. lol

No on the water jacket / stud.

Your best option would be to try in-car pinning of the stud.
Tons of protective precautions and magnets while in drilling process.
It won't be easy with hand drill since the cast will drill pretty easy and the stud will be like fort knox.

Probably should pre-drill the hole in the cast, enough to make a witness mark on the stud. Then pull stud, and have it drilled in a jig with a drill press.
Complete hole in the cast- through to other side.
Then with precision care - reinstall the stud and install roll pin, and stake it.

sounds yummy don't it

2. Could try pulling stud out - knurling - loctite - drive back in, as a first line effort.
Not too much to lose compared to where you stand presently.

[ponyakr]

Yeah, the roll pin--that's what we did in the old days. I did one on a 350 sbc truck motor. It worked. But I used a better bit--like a titanium coated or something. If you decide to go with screw-in studs, many agree that it is better to have heli-coils installed, rather than the ARP studs with the larger base threads. That way you can either use stock Pontiac studs or 7/16 Chevy studs the length you need.

http://www.summitracing.com/parts/mr...cJ-RoCYBzw_wcB

[rexus31]

Best solution: Pull the heads and have screw in studs installed. I know you didn't want to hear it, but there it is. If one has started to pull, I think it is only a matter of time before another will.

[Dick Boneske]

As I told Rich on the phone--I've pounded studs back in Pontiac engines a few times in my life! When I missed a shift on my new '64 and revved past about 5,500 rpm, valve clatter would follow as the lifters had pumped up. If the noise didn't go away after a few seconds, a pulled rocker stud was the cuprit. The Royal Pontiac trick with the Polylocks and adjusting the lifters to near the top of their travel helped a lot--both with lifter float and stud pulling. After doing that, my stock '64 was OK with a shift at 5,600 rpm. It went through the traps at 5,400 rpm with the 3.90 gears.

Some guys pinned the studs as Baron described, but I know at least one case where the stud broke where the pin was drilled. Maybe too large a pin was used, but that risk and the metal chips in the rocker arm area scared me away from ever doing this.

Remember, the rocker studs are a pressed fit into the head. Whatever caused the stud to pull partway out did not change the size of the stud or the hole in the cast iron. Maybe after multiple times, the stud would be looser, but not after one or two times. An old Polylock with the setscrew removed is a safe way to protect the top of the stud when doing this.

[b-man]

I'd pound it back in.

If the problem comes back within a short time pull the heads and install screw-in studs.

If it doesn't give you problems for a long time then you can put off installing the screw-in studs for a while, but eventually you'll need to.

An attempt to pin the studs can likely ruin the heads, don't repair it this way.

Nice 9770716 heads are getting hard to come by, be careful with yours.

[War eagle]

X2 b-man. The original stud is hollow and drilling thru weakens it. If you break it off, then you really have problems. I don`t use heli-coils and I purchase ARP 290-7201 studs. The important thing here is to use an H1 tap. The tap makes a tighter thread than the normal hardware store tap. Isky also has studs that work just as well but again the special H1 tap is a must.

[Rich-Tripower]

It took a dozen or more pretty serious whacks to get it fully seated back in place so I'm hoping it will stay put. But then, it had pulled out so apparently valve spring pressure was enough to pull it out in the first place. Maybe it was like that when I began and got there from the 84,000 miles of use previous? My cousin used to drag race the car on a regular basis and had 4.88 gears at the end so I'm sure it saw some revs over the years.

[War eagle]

I drained OLD gas from a tractor I rarely used and rather than throw it out I poured it into one of the old trucks around here that I use frequently. It pulled a stud when it backfired and with a hammer and fresh fuel everything has been fine for 5 years. I think the old gas caused the valve stem to seize briefly and pry the stud out. Lots of fulcrum force there. Nothing to do with valve spring.

[Willshire]

When you decide to put screw in studs in make sure you have rockers with pushrod holes in them or it will oil starve. The 716's were stud oiling IIRC same as the 345's. Older ,wiser better, will know more than I

[Rich-Tripower]

Originally Posted by Willshire

When you decide to put screw in studs in make sure you have rockers with pushrod holes in them or it will oil starve. The 716's were stud oiling IIRC same as the 345's. Older ,wiser better, will know more than I

Nope, the GTO version of the heads on these 389s were modified by the factory to provide pushrod oiling. One of the unique things about the GTO heads which makes them unique and hard to find.

[Willshire]

Originally Posted by Rich-Tripower

Nope, the GTO version of the heads on these 389s were modified by the factory to provide pushrod oiling. One of the unique things about the GTO heads which makes them unique and hard to find.

Was the 716 a GTO only head or was it a tripower head? I think i see what you mean. the 716 was a tripower head but the GTO only had pushrod oiling?

[Rich-Tripower]

Originally Posted by Willshire

Was the 716 a GTO only head or was it a tripower head? I think i see what you mean. the 716 was a tripower head but the GTO only had pushrod oiling?

I don't know. I know it was a GTO thing for the GTO, both tripower and 4-bbl GTO heads have pushrod oiling. Not sure how or where else these heads were used.

[ponyakr]

Originally Posted by War eagle

X2 b-man.

I don`t use heli-coils and I purchase ARP 290-7201 studs. The important thing here is to use an H1 tap. The tap makes a tighter thread than the normal hardware store tap. Isky also has studs that work just as well but again the special H1 tap is a must.

http://transamcountry.com/community/...c=23910.5;wap2

[b-man]

The 716 heads were used on '63-'64 421 HO engines and some big Pontiac Tri-Power 389s, the only 4-barrel 389 to use these heads was the 325 HP standard GTO engine.

First pushrod-oiled head other than Super Duty.

All used the hollow oiling studs and for many years thereafter to use up the inventory.

[Willshire]

And there you have it!!! Thanks b-man