Does this engine sound healthy?

[Getter-Done]

Originally Posted by guyryan100

I took 2 rockers off today to get exact measurements.

The problem valve's rocker stud is indeed pulled out 1/8" which is the same amount as the excess lash.

I know I could remove the head, remove the stud, and tap for a screw in stud.

Or I could just put it back together and see if it gets worse.

Or I could carefully hammer the stud back down and then put it back together and monitor.

I don't really want to take the head out and am not going to risk tapping it myself, am I taking a big risk if I take my chances? I also thought about drilling a pin through it to hold the stud in place after I hammer it back down.

It is going to pull out again if you tap it down.
Probably instantly because of the extra wear of tapping it down.

If you do not Remove the head there will be metal shavings involved.
Which will not end with good results.

If you try to do a roll pin thing.
Which will be a Temporary fix.????

Also, If you drill and tap these need to be drilled at the Proper angle.
For screw in studs.
The geometry is what keeps these from wearing out before their time.

With my opinion stated.

Would you feel comfortable driving it down the road like this?
If it was Patched up.

If it were mine .

Screw in studs in your current heads done by a Good machine shop .
Or buy a new set of Heads.

JMHO
Hope this helps.
I have had a set of heads that had this issue.

They were replaced.

[Ironangel]

Originally Posted by guyryan100

I took 2 rockers off today to get exact measurements.

The problem valve's rocker stud is indeed pulled out 1/8" which is the same amount as the excess lash.

I know I could remove the head, remove the stud, and tap for a screw in stud.

Or I could just put it back together and see if it gets worse.

Or I could carefully hammer the stud back down and then put it back together and monitor.

I don't really want to take the head out and am not going to risk tapping it myself, am I taking a big risk if I take my chances? I also thought about drilling a pin through it to hold the stud in place after I hammer it back down.

You dont have to pull the head. You have two options, drill and pin the stud, or pull the stud(s) and tap the hole(s) with a 7/16"-14 tap. I would pull the stud, then tap the hole, apply red Loctite to the stud and torque it to 35-40 ft lbs. You can buy a tool and a set of 3/8" studs here, https://www.speedwaymotors.com/SBC-H...ds,379470.html I recommend buying this kit because if one or two pulled you can bet your hat more will follow. It's $40 bucks well spent, you will have to buy a 7/16-14 tap. The holes are already .375" diameter so drilling for the tap is not necessary! Place an oil soaked shop towel around the hole to catch any cuttings, a shop vac is handy too. You can grease the tap to catch most of the cuttings. The tool is used to pull the stud, and then to align the tap keeping it square to the hole. By placing the tool over the neighboring stud, it will keep the tap centered as well. EZPZ...Dont forget the red Loctite...

[guyryan100]

Thanks Iron, that matches my own research and I think I'm comfortable attempting it since I don't have to bore a larger hole - its just tapping an existing hole.

My one question is, at the bottom of the hole is it open, meaning metal shavings will fall through, or is it closed? I've read its both, I think that depends on what heads you have. I have basic iron heads.

Knowing that jig exists is a big help, I have a fighting chance of not screwing it up.

Ryan

[72SB]

You will see if its a blind hole when you pull the stud. The tap looks to be a "bottoming tap" which would be the kind you use on a blind hole.

[geezer#99]

Despite all the awesome advice you’ve gotten, I’d leave the stud alone. Put it back togethor and see if it runs quietly. If it does then look into fixing the stud. If not then you’ll need to dig deeper.
Could be a bad lifter or the dreaded flat lobe.

Also your video shows a distinct lack of oil on the rockers. Should be little pools of oil around each rocker ball.

[Ironangel]

Originally Posted by guyryan100

Thanks Iron, that matches my own research and I think I'm comfortable attempting it since I don't have to bore a larger hole - its just tapping an existing hole.

My one question is, at the bottom of the hole is it open, meaning metal shavings will fall through, or is it closed? I've read its both, I think that depends on what heads you have. I have basic iron heads.

Knowing that jig exists is a big help, I have a fighting chance of not screwing it up.

Ryan

Some holes do indeed penetrate the water jacket, no worries because if some cuttings do fall into the water jacket they will likely rust away or find a home at the bottom of the block or radiator. If you coat the tap with wheel grease and take your time cleaning the tap and regreasing it two or three times before reaching the final depth, there will be little or no cuttings falling into the water jacket. When you pull your first stud you'll be able measure the depth of the hole. Measuring the length of the screw in studs from the bottom of the hex to the end of the 7/16-14 threaded end of the stud you'll be able to gauge your tap depth. The kit I posted does not contain a "bottom tap" or any tap at all, you'll have to purchase a tap or taps. (I'd get one of each, a bottom tap and a self centering starter tap if money allows) The aligning pin pictured with the kit is used to align the tool when working on heads with no stud in the adjacent holes. The tool should be centered with either an exiting stud or the pin. Use the big hole for aligning the tap. Use a grade 8 flat washer on the tool when your pulling the stud, nut wont mar the tool. I think that's it..."Walk in the park"

[Myself]

I had that happen years ago on a 305. I used flat steel across the other rocker arms to pull the stud maybe 1'2" out, put a few light grroves into it with a hacksaw blade, smeared red loctite on it, then hammered it back down, then I dimpled the boss a couple times with a punch. Maybe a few hundred miles later I THOUGHT the same thing happened again and I would have to pull the head........NOPE, flat lobes on the cam which I believe started the whole thing in the first place. Stud was still in place though LOL!

[guyryan100]

Update: I successfully pulled out the press-in stud, tapped the hole, installed a new screw-in stud, and put everything back together, with valves adjusted.

I'm giving the Loctite time to fully cure before I run the engine.

More detail:

* The tool above helped with extracting the press-in stud but I needed to add several washers to pull it all the way out.

* Using the tool above, tapping threads into the hole was not difficult or risky. Without that tool it would have been tricky to do this with the head still in the engine because its hard to reach and at an angle. But the jig in the tool above made it impossible to get it misaligned.

* I used grease on the tap and Q-tips to remove all the shavings.

* I had to remove rockers from 3 adjacent valves to get the tap to screw in deep enough.

* I used these taps: https://www.amazon.com/gp/product/B00FXJWFZ6/

* And this tap wrench: https://www.amazon.com/gp/product/B00062BNOO/

* I did have to rotate the distributor to get the vacuum advance out of the way of the tap wrench, so I'll need to adjust the timing.

As always, thank you all for your help.

[53burb]

GREAT! thx for the follow up!