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Discussion Starter #1 (Edited)
I snapped off a valve cover stud on my Aluminum PRC cylinder heads. These studs thread into the valve cover retaining threads and then the valve cover screws into the threads on these studs. It said to torque the studs to 45 inch pounds. I set the wrench to 25 inch pounds as a 1st pass and it snapped one off. The others went in fine. I was able to drill it out but I couldn't get a full thread cut depth on it. I can screw the stud in but its kind of loose. Is there any type of EPOXY that would work for this? ie; withstand heat and vibration? The bolts are only torqued to 45 inch pounds and then valve cover bolts get screwed into the studs.

Thanks,
Keith R
 

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25 in/lb is only 2 ft/lb, noway you snapped that with a 1/4'' drive torque wrench. Wow! What torque wench did you use a 3/8'' drive one? If so you put 25 ft/lbs on it. Most all in/lb torque wrenches are 1/4'' drive.

You need to heli coil it. Drill out and install heli coil and tighten don't over torque. Google heli coil install and read also plenty of info on youtube I am sure on them. No way I would expoy that nothing will hold up like that.
 

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Discussion Starter #3
BO185 it was 1/4 torque wrench with only NM/In. lbs I have used it many times and it seems to be accurate so I am pretty puzzled by it all. Yeah I was thinking heli coil but was hoping for something a little easier. Long day today.. I will get up tomorrow and start again!!
 

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BO185 it was 1/4 torque wrench with only NM/In. lbs I have used it many times and it seems to be accurate so I am pretty puzzled by it all. Yeah I was thinking heli coil but was hoping for something a little easier. Long day today.. I will get up tomorrow and start again!!
Wow, yeah that's weird. I would get it calibrated to check it if you live in a decent size city usually place that will cal them for you for a small fee. It may be damage. If its ever been dropped the its pretty much out of cal.

On stuff like that in/lb and its just holding a stud I will use good ole hand torque wrench. :)

Heli coils aren't bad just take time and keep every thing clean.
 

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Discussion Starter #5
BO185 you got me thinking about the wrench so I go out in my shop and set it to 25, 30, 40, 50 inch pounds and test it on a bolt. and guess what?? It failed to click at all two out of 5 times. I used pretty regularly on this build and never had and issue (as far as I know) time for a new wrench....


Thanks,
Keith R
 

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What brand is it? Most name brands can be fixed in cal.
 

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Discussion Starter #7
BO185 it's a Tekton. I have had it for about 2 years and seemed to work well. Maybe dropped on the bench to hard or something. Maybe i'll get a better one.
 

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Ahh yeah most those cheap torque wrenches won’t even cal. I know the company that did our cal on torque wrenches fail most of them. For 1/4” drive really need a nice one for accuracy. MAC or Snapon but they are $$$! The 3/8 and 1/2” ones usually craftsmans ones will hold cal.
 

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I had a Craftsman heavy duty click type torque wrench (actually 2) that did that immediately when new. Wouldn't click even on a low setting. I gave up on it after the second one and bought a Snap On. That was 40 years ago. The junk Craftsman wrench has a long handle and works nicely as a ratchet for turning the engine over when adjusting the valves etc.

A simple beam type torque wrench is far more forgiving as far as damage and keeping its calibration. I keep my first beam type 1/2" drive torque wrench that I got over 50 years ago as a gut check on the calibration of my bigger click type torque wrenches. I use only beam type for the smaller stuff. If a beam type torque wrench reads zero with no load on it, its calibration hasn't changed.

An anecdotal story here. I got a tooth implant a few years ago. That's where they put a piece of titanium all thread in your jaw or skull and attach a dental crown to it with a titanium nut. The dentist had a tiny titanium torque wrench to tighten the nut. I'm sure it cost him plenty, and I made a big payment to help him pay for it. It was a beam type torque wrench.
 

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One problem you may have with putting a helicoil in a blind hole is that the tap may not tap deep enough. You may have to tap until the point bottoms, then grind the tap shorter to make it a "blind tap". In fact you may have to do this twice, the first time shortening it leaving a bit of the taper, and the second time removing all of the taper.
 

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If it didn't have to come out again JB Weld WILL hold it without a doubt. It was holding bolts tight in my old transmission case! I've used it for many repairs and it's darned good stuff. The shifter knob on my ratchet shifter was stripped. Used JB Weld. Been solid for 7 or so years. Many things I fixed with that stuff. If you have to remove the part, you may have to torch it til it's really hot then it will come out again. I use carb cleaner to clean the hole, followed by compressed air, alternate the two a couple times. They now make JB quick weld which will probably work also, it's about half strength but sets and cures fast.
 

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M6x1 helicoils. The helicoils aren't very deep, should be half the length of the bolt threads, so should beable to drill and tap just fine. Drill size is listed on the box. Just mark drill bit to account for tap point and Don't go deeper than bottom of hole and you'll be fine.
https://www.amazon.com/Heli-Coil-Helicoil-5546-6-Metric-Coarse/dp/B0002KKPXK

And yes its $21 shipped to your door. And yes JB weld is $5, but you'll spend at least $10-15 in gas if one has to go get it, gas isn't free.

Do it right and never worry about it again.
 

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Discussion Starter #13 (Edited)
Yeah my 1/2 & 3/4 torque wrenches are Snap-On which i have had for 35 years and they still hold calibration. I will get a good new 1/4 one. I broke my own rule on never buying cheaper tools. I must be getting frugal in my old age!!
 

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I pulled a good one, I had a 3/8 adapter on my 1/4" torque wrench and mistook it for the 3/8 (it was large). Then I set it for something like 15 inch pounds thinking it was foot pounds. I went to torque and didn't even feel the click at 15 inch pounds since I wasn't expecting it. I kept going and going thinking something doesn't feel right and stopped just a little too late. Stripped a hole and had to fix that. And after going so far past the 15 in lb click, threw out the torque wrench. I'd like if someone made female to female 1/4-3/8-1/2 adapters so I could compare my different wrenches to each other. I'd use the beam type ones as the "calibrator checkers".
 

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Discussion Starter #15
55 Tony is there a particular JB weld that is high heat and strength for using on a cylinder head repair like this??
 

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55 Tony is there a particular JB weld that is high heat and strength for using on a cylinder head repair like this??
"Original J-B Weld can withstand a constant temperature of 500º F. The maximum temperature threshold is approximately 600º F for a short term (10 minutes). Refer to individual product packages for more temperature information."

I'd say that will do it. I have already put it in a stripped hole then ran a bolt in and out adding more until I was sure the sides were coated well (cleaned first with carb cleaner and air). Then one last time with a clean bolt but with some oil on the bolt. Let it set 5 hours and remove the bolt. Let it cure the rest of the 24 hours and it's set to go. (file/mill the top even) Granted it's not going to be as strong as original, but it's darn good stuff. And if there is no worry about it not having to come out again, skip the step with the oil, it WILL STAY. If you need to remove it someday, hit it with a torch and it will come out.
 

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Discussion Starter #19
Update

I drilled out the broken bolt and used an oversized Time-sert coil (Big Cert) The oversized Time Sert uses a lightly larger drill bit and tap with the same sized inner diameter. This gave me a little more drilling diameter than the standard size time serts. Came out like new!!! Thanks for everyones help!!

Keith R
 

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One problem you may have with putting a helicoil in a blind hole is that the tap may not tap deep enough. You may have to tap until the point bottoms, then grind the tap shorter to make it a "blind tap". In fact you may have to do this twice, the first time shortening it leaving a bit of the taper, and the second time removing all of the taper.
Or, just get a bottoming tap, https://www.mcmaster.com/bottoming-taps
 
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