[projectman69]

Well, I was getting ready to assemble the 400 sb and #1 bolt on torque sequence had a crack going to steam hole. I was torquing everything down and then that one just decided to turn on me and only hold 30 lbs before it just turns. Can I leave it or do I need to fix it. I am putting vortec heads on it also.

[BOBCRMAN@aol.com]

You will need to heli-coil that hole..

I usually heli- the head bolt hole then tap the steam hole for a tapered plug (iron stitch type plug). Then plug/seal the steam hole and then re-drill the hole.. This will seal the crack from the head bolt thread.

[projectman69]

What size would that stitch plug be? And thanx for the heli coil info. Totally had forgotten about those. Man u made me feel much better. I thought my block was shot.

[DoubleVision]

A 350 we were looking at close on the deck one day had the same condition. But it had 3 cracks, one going to one bore, one going to the other bore, and the other going to a coolant port. The cracks going into the bores went down about a inch on both bores so we deemed the block scrap and not worth trying to save as not only would it need alot of deck work but it would need 2 sleeves as well. Look at your block closely to make sure it didn`t do this same thing. A 400 my brother in law was building did something similiar. He was torqueing the bolts down and heard a loud POP.
We yanked the head and the crack started at the bolt hole and went half way around the bore. Needless to say, instant scrap.

[projectman69]

I used a high power magnifier and couldn't see anything. It was like that before I took it apart the first time. I ran it two months this way and the head on the other side cracked so when I tore it down I saw this. I chased the threads and it seemed fine, but now I stripped it.

[projectman69]

Okay so I got the head off this morning and the number one hole still has great threads. It's just tht when I was torquing the nut down on the head stud. The stud was turning and ended up pulling itself all the way through the hole and the shank of the stud was spinning in the hole. About the upper half of the hole is stripped bottom half looks amazing. So I was wondering if red high strength thread locker would hold it still? I know I would have to clean the hole and everything so it cures good.

[projectman69]

I'm thinking that would fix it because the main problem I was having was the stud turning and with using strong thread locker on there I would assume it would allow me to torque the nut down to the appropriate 65lbs before the stud turns.

[projectman69]

Anyone know if that would work.

[cobalt327]

In for a dime, in for a dollar- use JB Weld on spotlessly clean threads in the block and the stud itself. Put the JB down the hole as well as the threads of the stud and screw the stud into the block. Wipe off any that might get above the surface of the deck. Let it cure then torque as usual.

Now, I've never done this, but I know of at least one respected member here who has advocated using JB Weld to hold studs in- studs that weren't stripped. This was done anyway, as security I guess.

[projectman69]

Originally Posted by cobalt327

In for a dime, in for a dollar- use JB Weld on spotlessly clean threads in the block and the stud itself. Put the JB down the hole as well as the threads of the stud and screw the stud into the block. Wipe off any that might get above the surface of the deck. Let it cure then torque as usual.

Now, I've never done this, but I know of at least one respected member here who has advocated using JB Weld to hold studs in- studs that weren't stripped. This was done anyway, as security I guess.

Well only the top few threads are messed up where the shank spun. There's still like 6 rows of threads. Outta be solid enough to have good strength.

[cobalt327]

Take my advice only if you choose to not do the helicoil/stitch plug repair. The helicoil/stitch plug would be a better repair, IMO. But the JB might get you by. If it was me, and I wanted the engine to be as trouble free as possible, I'd do the better repair. I don't know if the better repair will cause the deck to need resurfaced, though.

[projectman69]

Originally Posted by cobalt327

Take my advice only if you choose to not do the helicoil/stitch plug repair. The helicoil/stitch plug would be a better repair, IMO. But the JB might get you by. If it was me, and I wanted the engine to be as trouble free as possible, I'd do the better repair. I don't know if the better repair will cause the deck to need resurfaced, though.

Okay thanx. Yeah there's no chance I would be able to get the deck resurfaced. I really don't know of any shop around here.