Heli-coil alternative for mechanic in Montreal jb racing at end of thread

[midnight rider]

my head gasket was leaking and my mechanic replaced it and when he went to torque the bolts he found out that the previous mechanic used Heli-coils. when he tried to tighten one of them it slipped at 50/lbs of torque and i believe he said they should be 85/lbs. will a time sert work as a replacement for an 11 second GN or do i need a new block or is there another alternative

 

[larrym]

Studs might work I would be more apt to look for a new block if possible.

 

[earlbrown]

A time-sert might remove too much material and put you too close to the water jacket.

 

[TRICKSIXPA]

If using regular bolts torque is 60lbs. Can't the hole be welded and re tapped too?

 

[midnight rider]

arp bolts. im going to ask if it can be welded as i dont want to spend 1000 bucks or so for a block then have to machine costs to fit my add ons

 

[bison]

If a heli coil is pulling out something else is wrong with it.

 

[charlief1]

arp bolts. im going to ask if it can be welded as i dont want to spend 1000 bucks or so for a block then have to machine costs to fit my add ons

To properly weld it the block will need to be cleaned and prepped, then heated completely to a red heat. Then it can be welded. It will need to be cooled very slowly, preferably in an oven that can be timed to keep from stressing the block. Then you'll need to have it dimentially checked and machined again. It will be cheaper to find another block in the end.

 

[earlbrown]

Didn't I read years ago about how someone was drilling the holes out and installing 1/2" studs with success? Granted it's overkill and not necessary but if they block is junk now, this might save it.

 

[charlief1]

Didn't I read years ago about how someone was drilling the holes out and installing 1/2" studs with success? Granted it's overkill and not necessary but if they block is junk now, this might save it.

I believe it was Neal that did that Earl, and it was a Stage II block and heads.

 

[bison]

The heli coil 7/16-14 tap is likely too big to leave enough thread to use a 1/2-13 tap. I've never measured but it's close

 

[QwikStop]

A good machine shop can make and install a insert to repair that hole...I work for a Cat dealer and we have it done on various items with some exceeding 850ft lbs torque with no issues...

 

[The Radius Kid]

Have a look here:

http://www.timesert.com/html/catalog.pdf

 

[aminga]

Didn't I read years ago about how someone was drilling the holes out and installing 1/2" studs with success? Granted it's overkill and not necessary but if they block is junk now, this might save it.

I did a search for larger stud and it lead me back to my profile page.

Searching for 1/2" stud let me to Ty's.

Here's the article though.

http://turbobuick.com/forums/threads/anyone-tried-1-2-head-bolts.294439/

 

[earlbrown]

I doubt it'll fly. I don't know what the tap drill is for a 7/16-14 heli-coil, but I'm guessing it's bigger than a 90+% tap drill for 1/2 studs.

Keep in mind, one of the things that make heli-coils work so well is that they put outward pressure on the host material when tightened (instead of linear pressure trying to rip the threads straight up).

The physical location of the bolt hole relative to the water jacket is pretty much a crack waiting to happen.


Then again, it might work. I've never actually tried it.

 

[coach]

I agree with Bison. If the Heli Coil is pulling out...you have a problem. If it just twisted...it need to be Loc-tite'd into place. Heli-coils are just as strong as the original threads as long as it was installed correctly. If the wrong size drill were used to install it...you could have less bite on the coil then it requires. If your original thread was really messed up...there may have been a lack of material to set the coil into. I still bet if it is Loc-tite'd in to place...you'll be good to go. I also agree that at least a stud in that position would be wise.

 

[midnight rider]

Thank you all so much for this wealth of information. ill have my mechanic have a look at the other options starting with why the heli coil is slipping.

 

[earlbrown]

Sounds like someone in the past was trying to overcome head gasket blowing issues....


.....to the point they tried overtorquing the shit out of the bolts. Sounds like a replacement block is in order.

 

[larrym]

1 or 2 helicoils perhaps but 75% that's a stretch.........

 

[coach]

How thick is the deck on our blocks? I have 2 put away, but never checked.

 

[bison]

Personally I would not use or attempt to fix that block. It's a lot of work to not have that confidence that it will be ok once together. There's a good chance the thread inserts aren't even in at the correct angle. I've never seen a block lose threads unless the installer made a mistake at some point. I have heard of people using the bottom row bolts in the upper corners which pulls the threads out because of lack of engagement. Trying to heli coil that in the car would leave a huge room for error. The drill will do whatever it wants. Even though it's got a nice hole to follow it can still be a problem.