[spectramitch]

Its definitely leaking from that stud. I rented the tester from AutoZone and checked it as is. Water started to seep from that stud. I removed the stud and checked it. Used my fancy amazon bore scope to look down in hole. Looks like its coming from either the bottom of the head itself or head gasket. But it's hard to say whether or not it was leaking there because there was no clamp from the stud on it.

[steve25]

Was the stud perhaps bottomed out in the hole when the head was last bolted down?
If so then the clamping loads may have simply been less then what was needed to seal the head gasket.

At any rate even though is a PIA I would pull that head off to fully check everything.

[chiefbigb]

Get the hole clean and dry. Put pressure on it again and see where the leak comes from. If it's coming from the head bolt hole I would drain the cooling system. Get everything clean and dry again and put some type of sealer on the stud threads. Install it and torque. Let that sit up and refill. You should be fine like that. Chevrolet head bolts went into the coolant for many years.

[steve25]

The problem with going that route is this.

If there is a crack at the bottom of that head bolt hole there is then a really good chance that it will continue to spread and in time then really screw you!

If I found / pinned down a crack in the bottom of a head bolt hole in my motor then I would simply drill out the bottom into the jacket, totally clean and dry it out and then use sealer just like the SBC guys use.
At least then you stand a chance of eliminating the crack and you can then sleep at night and go on your merry way.

If there’s is found a crack running UP the wall of that head bolt hole then the needed torque to clamp the gasket down on that corner will never be achieved ( at least by means of a bolt) and unfortunately the block is done!

In thinking about this a bit more, if a crack is found in the wall then the use of red Loctite would be my pick over sealer, as that might buy you some run time.

[mgarblik]

With the engine in the car, your options are a little limited. I don't see a big down side to trying to seal this stud, especially in a race car. If you want to use Locktite product, I would seek out Locktite, high solids hydraulic sealer. Regular high strength like 271 or medium strength 242, likely will not seal a crack, not designed for that. They are too thin and can't seal out the air to cure. Locktite 545 might be worth a try. I like Permatex aviation Form a Gasket liquid for this application. I would not bottom the stud, let it float in the block. Snug then back out 1/4 turn. Torque it in place, re-pressure test. Not much to lose. Just keep an eye on it.

[spectramitch]

What is the theory behind turning the studs back the 1/4 turn? I have heard that many places but ARPs instructions say " it is extremely important to ensure that the studs are fully bottomed out in the hole in the block and not hung up on damaged or corroded threads in the block preventing the stud from being fully seated."

[Dragracertoo]

My $.02, Never had any luck with Felpro 1016, never had a problem with Cometic

[mgarblik]

The problem is essentially where the stress is applied to the block structure, especially an iron block. If the studs were the perfect length and the threads ended exactly at the top of the block deck surface, I would be OK with that statement. In a blind hole, like a Pontiac, if the stud bottoms out before the threads are used up on the bottom of the stud, burying the stud in the hole is how the block becomes cracked. In a SBC, where all the bolt holes pass through the deck and all are wet, this is not an issue. However, I still do not like the larger diameter of the stud above the threads bearing down on the brittle deck surface where it can create a stress riser and crack the deck. Aluminum blocks are different. They generally take studs with a bullet nose end on the stud that is supposed to be buried into the soft aluminum material at the bottom of the bolt holes. There is often a torque spec. given just for the stud like 20 ft. lbs. I would take issue with ARP saying not to let the stud get hung up on bad threads. IMO, the stud should not be installed in a hole with bad threads until that situation is resolved with clean chased threads or a repair insert. I think they are more or less saying just make sure they are fully installed. I have learned allot from ARP and will try to get some clarification.

[chiefbigb]

I have seen many small block 400 Chevy engines cracked from the head bolt hole to the cylinder and the owners say yeah it's been like that a while. Run it till it becomes a issue.

[spectramitch]

https://youtu.be/FoUxFemTR28?si=b-pIj8xxeu6IPFgI

Its looking like the worse case scenario. I cleaned hole and re-pressurized. In the video you can see me blow off the 3 water droplets on the counterbore. Shortly after the 3 droplets reappeared. Mike do you think those coolant tablets will help me?

[PAUL K]

That's a bummer!

[spectramitch]

What if I made an aluminum spacer that was about 3/8" tall, that fit well in the counter bore fully seated flat. Then I use some good epoxy on the bottom and the sides?

[steve25]

Long before Cometic came to be I have run the 1016 with 8 psi of boost and just head bolts and never had a problem, things just need to be done properly mechanical,y and no detonation please at least under boost pressure.

[Ray Cox]

Haven’t seen anyone mention it and I assume you already checked but thought I would mention it to be sure.
Did you check the head stud length? With parts quality control these days things happen. Or if the head was decked more.
Make sure when you’re torquing it the nut is not bottoming on the threads before it’s fully tight. We have had some that after decking the heads a lot the stud was a few thousands too long. We added another head stud washer to get the proper torque.

But there are plenty of types of motors that have studs that go through to water jackets. On those type motors they put silicone in the head studs and seal them up. I think it would seal with silicone no issues.

[Ray Cox]

Haven’t seen anyone mention it and I assume you already checked but thought I would mention it to be sure.
Did you check the head stud length? With parts quality control these days things happen. Or if the head was decked more.
Make sure when you’re torquing it the nut is not bottoming on the threads before it’s fully tight. We have had some that after decking the heads a lot the stud was a few thousands too long. We added another head stud washer to get the proper torque.

But there are plenty of types of motors that have studs that go through to water jackets. On those type motors they put silicone in the head studs and seal them up. I think it would seal with silicone no issues.

[spectramitch]

Its definitely not the threads in block leaking. The old version eheads are weeping water from the counterbore. I dont think ill use epoxy for the spacer plug im going to make, I'm now leaning more toward using the permatex aviation sealer or maybe RTV.

[chiefbigb]

I have sealed up leakage with gasoila products in situations like yours.

[blueghoast]

The motor in my 57-wagon is leaking in the same place.
It's leaking in the hole of the head where the stud go's.
I left the intake and valley cover off and the oil pan to find
the leak. I filled through the thermestat hole then I seen the
leak and it was coming from the hole in the head for the stud.
I think I'm gona try and sleeve that hole with brass tubing and
JB-Weld the ends I'll silicone the sleeve before installing (RTV)
I think I'll also RTV the top under the washer too. I'll let ya all know

GT

[mgarblik]

Great video. You can see the water weeping around the crack in the OD of the counterbore. That's the regular crack area. I think machining the counterbore for a step washer and JB welding the step washer in place will fix it. The right way to do this is pull both heads, set them up in a mill and cut all 20 holes for step washers. Now that that is out of the way you can fix this single one on the car if you have room to get a cordless drill in there. I have step washers, 1/2" size I think. Have to look tomorrow. I also am not sure if I have the counterbore tool. I have all the stuff for the big 9/16" studs we used for sure. Just not sure about 1/2". If I have the tools and if you have room for a cordless drill, you can drill for a step washer with a hand drill, glue it in and your back in business. PM me and I will check in the shop tomorrow.

[JSchmitz]

Also have to be careful, with blind holes, not to have water or oil in the bottom of the hole. Always clean them out thoroughly before installing bolts or studs. You can hydraulic the hole and break the block. I like to tighten them down slowly and in steps.