BARF, just had a 625 stud pull out of the block, was on the 4th and final torque down, and just as it hit 150.....POW!!!!!

The threads were in perfect shape in every hole, chased them with a bottoming tap before, and the stud was all the way in, just finger tight.

I thinking 150 lbs with that arp lube is on the HIGH side, I was marking the nuts and on each re-torque was getting a little more, the nuts and washers have a real polish to them now. The nut's flat side against the washer is offering little resistance.

Now the fix....
So I've got the whole set of Helicoils, including metric, so I can go that way, BUT if one can pop, how about the rest?
JUST one weakling of the bunch?????

Any one helicoil a head bolt hole?

&*^% should have drill'd for 14mm's or 9/16's

I should still, just drill them all, after this not going to have that warm fuzzy feeling about some strong studs in the block, more like, wow, just sitting on the edge of hold or fail.....

I guess, I'll check the od of a helicoil, and make sure that don't screw up my option of drilling out to a 14mm or 9/16's, If not might as well give it a try.

 

ouch! That sucks! Good luck getting it fixed.

 

Wow! That is the first I have heard of this, I am feel for ya. Good luck gettin her fixed and keep us updated on how it works out.

 

Key note *** Did you not back them out any after they bottomed out ?
If you didn't, I would say that was their demise

 

had a truck that came in once with 13 holes on the deck helli-coiled (no I did not misspell the word LOL) It held for a couple years that way and left go after the owner drove like an idiot, blew a turbo boot, got the engine hot, blew the pyro out of the manifold and then cracked the head. LOL Thank God that baby is out of my hair.

Personally, they held for the time and probably would have been fine, had the fool that installed them bought the proper size helli-coils on the first go round. Instead, he installed two small ones in the same hole. Then when I tried to back the studs out of the block to do the head gasket, a couple of the coils moved in the block and bound a couple of the studs up. What a PITA. Good luck with it.

 

Just to clarify, i DID use the molly lube, and all the studs were backed out a little, just to make all even.
Even used a caliper to make all proud the same, except cylinder number 6, that was drilled more shallow for some reason, I bottomed those studs, just cause I hated how they stuck up 3 more mm than the rest.

 

Wow.... that sucks. Dont they make bigger diameter studs? Maybe you can get 1 for that hole. I do know helicoils are extremely durable when installed correctly. We have used them before at work on bigger engines but they were not stressed as bad as ours.

 

Ok, thanks, so I might get away with one. WOW 13.

I imagine it gets old fixing on a dudes truck that you know is just going to blow the hell out of it.

Ever tell some one your just done fixing their sh*& cause their a idiot?

 

Yeah there are bigger studs, and am really considering tearing it back down to just the block and putting some 14mm or 9/16.

I've had good luck in the past with helicoil's too, this would be a new situation though.

 

no comment. LOL

 

The dammage is done while bottom tapping with the head on. A lot of folks have pulled a stud out after bottom tapping. I wouldn't take a chance like just for cosmetics. I'm sorry it happend to you.

 

Not to be sarcastic, but I have been expecting this post ever since these 625's came out. Good luck buddy. Jay

 

I didn't bottom tap with the head on, did it with the head off, and to get all the stud in the block I could, arp recommends it.

So why would you pull out a stud after bottom tapping?

 

If you had your head off and didn't turn any threads while tapping the block must not be strong enough to take 150 ft lbs. Did the studs feel snug in the block? 125 ft lbs using moly assembly lube is quite tight. 150 ft lbs is very tight. You may want to have your torque wrench calibarated before trying it again.

 

Yeah like I posted on another forum, the studs did feel good in the block, I think 150 lbs is really on the edge, and it wasn't my day.

I can calibrate a torque wrench and checked it before I used it, #150 was bang on. Didn't need to compensate one way or the other. Checked it after too!!

Your right, 150# with moly lube is up there.

Lots of people are up there though, heard 160 - 170 crazy high......