Block Helicoil

RoyLuke

RoyLuke

Well-known member
Apr 18, 2007
261
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Whilst I was torquing the last head bolt to the block, I felt that sinking feeling when the bolt gave-way. When I removed the bolt, the helicoil came with it.
The machine shop says the block cannot be repaired with a new helicoil and they will not attempt to try.
Before I piece-out this engine and take the block to recycle, does anyone have any ideas on salvaging this project ?

This aluminium block is plenty soft metal but I was not that close to the listed torque value.

Ugh !!!!

thank you
Roy
 
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terryjm1

terryjm1

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Jan 23, 2011
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Did you use the torque to yield head bolts? Or, did you use the ARP kit? Or, should I assume since you stated you went with a torque value you used the ARP kit?

I am asking as I am planning to use the ARP kit for the first time.
 
LRDONE

LRDONE

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Dec 3, 2020
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You should have the machine shop fill the hole with a TIG welder/ Drill and re-tap. What do you have to lose at this point? If your current machine shop won't do it, Find someone that will.

It's my guess that your first Helicoil was in crooked.
 
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RoyLuke

RoyLuke

Well-known member
Apr 18, 2007
261
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LRDONE said:
You should have the machine shop fill the hole with a TIG welder/ Drill and re-tap. What do you have to lose at this point? If your current machine shop won't do it, Find someone that will.

It's my guess that your first Helicoil was in crooked.
Click to expand...
That sounds like a really good idea. You've been doing this before .
The machine shop that did the heads acted like total wankers when I talked to them today. they refuse to even attempt.
To fill and rebore sounds like a good plan.
TNX
 
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boxster

boxster

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Jun 1, 2009
490
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Fallbrook Ca.
RoyLuke said:
That sounds like a really good idea. You've been doing this before .
The machine shop that did the heads acted like total wankers when I talked to them today. they refuse to even attempt.
To fill and rebore sounds like a good plan.
TNX
Click to expand...
TIME SERT maybe.
 
roverover

roverover

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Feb 27, 2005
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www.UsedLandRoverParts.com
Definitely use Timeserts never Helicoils A Timesert is at least twice as strong as the original tapped hole. That being said I had one we replaced several holes with Timeserts and they along with several other threads pulled out, turned out we had one of the infamous porous blocks.
I wouldn't weld and redrill I think even if the thread held it would have other issues down the road
 
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RoyLuke

RoyLuke

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Apr 18, 2007
261
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I am looking at Time Serts for the engine . Took a head bold to advance auto and it is either an M12 x1.75 or a 7/16" x 14.
Anybody know which it is?
What time sert should I order and what length sert?

1 flag.png
 
Swedjen2

Swedjen2

Well-known member
Sep 12, 2018
594
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California
RoyLuke said:
Whilst I was torquing the last head bolt to the block, I felt that sinking feeling when the bolt gave-way. When I removed the bolt, the helicoil came with it.
The machine shop says the block cannot be repaired with a new helicoil and they will not attempt to try.
Before I piece-out this engine and take the block to recycle, does anyone have any ideas on salvaging this project ?

This aluminium block is plenty soft metal but I was not that close to the listed torque value.

Ugh !!!!

thank you
Roy
Click to expand...
globeius.com

C-Sert

Your browser does not support the video tag. Fix it and Forget About it. The only permanent thread repair guaranteed. BY FAR THE FASTEST AND EASIEST THREAD REPAIR INSTALLATION FAIL PROOF: HERE'S WHY 1. S-7 Tool Steel. S-7 tool steel is both hard and tough. We through-harden it to 56 RC and...
globeius.com globeius.com

Similar to time-serts.

I replaced the ARP studs with bolts. Two of the bolts would not reach proper torque and it soon became apparent the threads where below standards.
After installing the c-serts and tightening the new bolts, well..."Bob's your uncle".
The use of helicoils should be avoided at all costs. You will soon be doing the same job twice...as you well know.
 
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LRDONE

LRDONE

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Dec 3, 2020
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Also, when repairing the threads, 1.5 x the diameter of the bolt is maximum hold. Anything more is a waste of time so don't be breaking taps going too deep.
 
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4Runner

4Runner

Well-known member
May 24, 2007
664
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Boise Idaho
Just my two cents, I would look for a different block. The machine shop would have to be very thorough about welding enough metal there and then vetting it. Then you would probably have to get the block decked to make that part flat again. There are other hazards with getting a different block for sure. If you get another block you can take an old head gasket and an old head bolt with enough spacers to mimic the head then go to each cleaned bolt hole and pre test it. If none of them pull out then take the block to the machine shop for a pressure test and prep work. I am sorry to hear the trouble you’ve been having. Some of these motors are just plain stupid with the things you have to deal with. My 4.6 was the most difficult motor to rebuild so far. 911’s, Alfa’s, BMW’s, Chevy’s, Ford’s, all more predictable and easier. Hell even my 94 LR 4.2 was a normal rebuild. Hang in there.
 
RoyLuke

RoyLuke

Well-known member
Apr 18, 2007
261
11
I went to a different auto parts store and used a size/thread gauge that was in a bit better condition and it looks like the the head bolts are 7/16X14.
Please correct me if I am wrong.
Now I look for an inexpensive (Ha Ha Ha) Time Sert kit.
 
boxster

boxster

Well-known member
Jun 1, 2009
490
96
Fallbrook Ca.
7/16= bolt diameter Standard Course
14= threads per inch
M12= bolt diameter Metric
1.75= thread pitch

Maybe just size it up at the Hardware store, they usually sizing gauge
 
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