Guys, i'm sure i am not the first to have this issue but here it goes....on my 1998 TA i broke the #3 passenger side head bolt, not sure if it was a defective bolt although it was brand new but anyways, i have tried every kind of easy out made with no luck. what broke was the very end approximately .75" of the long bolt that is #3 in the torque sequence....i have decided that i am going to go with a heli coil and shorter bolt instead of removing the motor and all of that, my question is where to find what i need to center bore the hole and which type of insert to use? this motor has a lot of miles on it but runs very well so i would like to be able to get a little more use from it before i swap it to a 6.0 or similar. can anyone please recommend where and what exactly to purchase, i know the bolt is a M11 x 2.0 so does that mean i need to find a M11 x 2.0 center bore and heli coil? any information or suggestions are greatly appreciated....thanks everyone!

 

No you are not the only one. I don't know about using a heli-coil though.

The Dealer would use Kent Moore J-42385-100 which contains the drills, taps, and Time-Serts with drivers for the head and main caps on LS blocks . Kent Moore J-42385-300 is the locating plates for the LS block used in conjunction with the J-42385-100 kit.

Some Engine shops are skilled enough to also preform this type of repair.

 

I would NOT UNDER ANY CIRCUMSTANCES WHATSOEVER use a shorter bolt in place of a head bolt.

Reason is, those bolts are torque-to-yield. They have specific metallurgy such that when the correct torque is applied to them, they "stretch" (aka yield) and then instead of acting like a "bolt" as we think of one, i.e. an unyielding clamping force, they become more like a spring, with very high tension. Diameter, alloy, and LENGTH are all critical to providing the right result; which is why the head bolt threads are way down in the block to begin with, is to accommodate longer bolts. Unless you can source a bolt of known metallurgy and all that, the odds of a hack job like that working right, are about as close to ZERO as you can get.

Now if you change all the bolts from TTY to traditional-design ones such as ARP then your chances are much better.

I also would NOT use Time-Serts for that. Reason is, their outer threads are "synchronized" (hence the name) to the inside ones. IOW you end up with the same crappy 1.25mm or whatever it is, SOOOOOOPPPPPPPPER FINE thread, in the aluminum, as the one that already failed. And of course the reason they fail in the first place, and GM published all that about repairing fornicated blocks with TimeSerts, was because the threads were too fine to begin with. Making the thing with the too-fine threads have a slightly larger OD butt still the same threads doesn't solve the too-fine-thread problem.

Used to be some d00d that made a kit for the Northstar engines, which use the exact same kind of bolts (11mm fine thread) and have exactly the same problem as the LS motors for which GM's "fix" was TimeSerts in those engines as well, which were widely known for ALSO pulling out of the block and scrapping it. Those motors are even worse about pulling the threads out of the block than LS motors for some reason. His kit used ½"-13 outer threads - BIG BEEFY DEEEEEEEP threads - in the aluminum, and then like TimeSerts, stock head bolts. It was so much larger that you could even repair a block that a TimeSert had pulled out of. You had to drill out the bolt holes to the ½"-13 tap size (or even the Heli-Coil for it), drill out the upper part of the hole to the clearance dia for that, then screw in his insert, which had like a slot cut across the top to drive it in. MUCH better than a TimeSert. They WORKED on those funky blocks, and STAYED working, where TimeSerts would often just pull out again.

If I was in your situation I'd drill out and extract the remains of that bolt, and fab up a repair as described. You'd need a good ½"-13 bolt that you could chuck up in a vise; drill & tap the center of it to 11mm x whatever the thread pitch is in a drill press; cut it off to the length of head bolt threads; drill out the block to the ½"-13 tap size, and tap it with a bottoming tap so that it's threaded all the way down, all of which you can do with hand tools; put in the insert; and use whatever head bolts you choose, in the stock size.

 

You need to use a timesert on that, not a helicoil. Timeserts are stronger than the factory threads. Its a much more complicated process than a helicoil. I did my entire block after a few head bolt threads stripped out.

 

This might be the kit I used on acoupla those; looks pretty similar to it anyway. Obviously VASTLY superior to the crappy TimeSert idea.

https://www.huhnsolutions.com

 

Crappy time serts lol....that's why pretty much every auto manufacturer recommends them. They self lock into place by expanding at the bottom. They aren't going anywhere.

 

Until they do... they STILL use the same fine threads as the stock bolts. IOW they don't fix the fundamental problem.

The reason the mfrs call for them is because all they're concerned with is getting the vehicle through the warranty period. Which usually by the time the head bolts pull out, is mostly expired anyway; if the car gets on down the road for a little while longer, they can then wash their hands of it. Long-term longevity isn't an issue to them.

Speaking strictly as someone who's been through the Castech head problem, which GM completely ignores, since it almost always happens after the vehicle is out of warranty. That's all they care about.

Just not the best way to actually REPAIR a failed block; or to replace a damaged hole from an extraction operation, if it ends up doing that. ONE LOOK at the alternative makes it obvious how much BETTER they are than TimeSerts.

 

The issue with the block threads comes from removal of the factory bolt pulling the aluminum threads with it. Seeing as the timesert is steel and physically locked in place by biting into the block, the threads never move nor have a reason to move, so theres no way to pull the threads out. Fine threads hold a better clamping force over course threads. Hence you see fine thread hardware holding engines together in the 1st place.

 

If you clean and Red Lock tight them in place like they are supposed to be, you shouldn't have any issue. Make sure the Lock tight isnt 10 years old too...
I think the main issue is that most people doing them don't take there time and are not careful during the drilling and taping phase. They try to drill the hole out as fast as they can and jam a tap in there in 1 shot.

The main difference between the Time sert and what you have shown, is they use a coarse thread. I am not dismissing that it is probably better and less likely to have installation error.

I do agree it will bight better with a coarse thread.

They do also have a kit listed for the early and Late LS engines. https://www.huhnsolutions.com/general-motors

https://static1.squarespace.com/stat...N+III+ALUM.pdf
https://static1.squarespace.com/stat...AND+IV+ALUM.pd

The OP may get lucky and might be able to extract what's left in the hole if they took there time to drill and get an extractor in there.