TIME-SERT 102: How to Install Threaded Steel Inserts into the GM Atlas 4.2L LL8 Engine Block Head Bolt Holes


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TIME-SERT 102: How to Install Threaded Steel Inserts into the GM Atlas 4.2L LL8 Engine Block Head Bolt Holes

Part 1 of 3 Parts:

The Problem:

With the advent of High Quality Steel TTY “Stretch Bolts” in use inside of Cast Aluminum Engines came the problem of having TTY Fasteners invariably BREAK both during Assembly and randomly during Disassembly. In the case of the Engine Head Removal from the GM 4, 5 and 6 Cylinder In-Line Atlas Vortec LL8 Engines, it can become very problematic if ANY of the Bolts Holes get STRIPPED OUT or suffer any damage in the adjacent Aluminum Block Metal that will defeat the ability of the Head Bolt(s) to maintain their hold between the Engine Block, MLS Gasket and the Engine Head:

Additionally, for those of us having faith in these Amazing Aluminum Engine Blocks that extends to a desire for Additional Horse Power and Torque, the sensible approach would be to strengthen the critical Threaded Fastener Holes in the Engine Block. Such Fasteners are those that are holding in the Heavy Crankshaft and the Rotating Assembly as well as the need to restrain the Engine Head and Stainless Steel MLS Gasket firmly to the Engine Block under the stress and strains of using Superchargers, Turbochargers and/or Nitrous Oxide.

In Parts III of this Article, I'll be showing the installation of (14) of THESE (20) TIME-SERT M11 X 2.00 X 30MM Threaded Steel Cylinders on a Stand-Mounted GM Atlas 4.2L LL8 Engine Block:


These issues can be addressed by taking the active approach of re-fitting the involved Bolt Holes using the TIME-SERT System. This means manually modifying the Engine Block to accept TIME-SERT SI Machined High Strength, Threaded Carbon Steel Cylinders. When these “SERTS” are Properly Installed… they can provide for a Stronger, Permanent Solution to these problems. It follows that I'll include a Photo-Play of All the Sequential Steps necessary to Do This Job Justice. These are the Basic Pictorial Stages for ALL TIME-SERT Installations (Excerpts from Linked Timesert.PDF):


The Added Advantage of installing the "SERTS is that the application of the Tightening, Torque and Torque-To-Angle FORCE can be accomplished with Greater Uniformity and Reliability.

The fact is that Winding Steel Bolts into Soft Aluminum Engine Blocks with resistance along the mating thread lines can cause the Steel Bolts to either GALL the Aluminum, Seize Up or even literally “Erase” the much softer Aluminum Metal while Pulling the Thread Lines Completely Out of the Engine Block during the Installation Procedures.

This will NOT occur once the Steel Bolts are Threaded into the Steel "SERTS" Machined Cylinders ...as long as the Factory OEM Torque Specifications are followed and NO Improper Use of Lubricants get applied to the Underside of the TTY Flange Bolt Heads or to the Thread Lines Prior to their Installation:


Continued in Part 2 of 3 Parts...

Link to Timesert.pdf:

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Part 2 of 3 Parts:

Ths is an Iimportant Retrospective on the Solutions I have used in the Past:

Assuming that you have NOT made the same mistakes I have made in the past and which will be covered in Part 3 of 3 Parts, once the GM 4.2L Engine Head has been removed… irrespective of whether or not (1) or all (14) M11 X 2.00 X 133 MM Engine Head Bolts have Snapped Off during Dis-Assembly, the following initial repair actions will apply:

(1) Do NOT Attempt to Extract ANY Head Bolt Remnants Prior to Completely Removing the Head.

(2) Assemble all of your Requisite Specialty Bolt Extraction Kits and Common Tools and prepare to array them within easy reach around the covered areas of the upper Engine Block:

(3) Before you Begin This Work… If you are CLEVER...You’ll make use of your Old MLS Stainless Steel Gasket by covering up all of the areas adjacent to the (14) Bolt Holes with either Gray Duct Tape or Black Gorilla Tape. In this way, you’ll be able to avoid making ANY incidental (accidental) contact with the Soft Upper Surfaces of the Aluminum Engine Block and cause them Damage.

(4) Cover the ENTIRE Upper Engine Block with Layers of Saran Wrap and then lay or position an expendable White Cotton Towel around the immediate Work Area, Doing this will allow you to have easier access to everything on a nice contrasting surface such as all of the Drilled Out Metal Trash that needs collecting with a Neodymium Magnet.

NOTE: The Tough, Sharp “Swarf”... (Call this ‘Metal Junk Afterbirth’ whatever you will) that gets created while Drilling into Hardened Steel Bolts will RUIN the Cylinder Walls if any of that Stuff accidentally drops inside and gets wedged in between the Pistons and the Cylinder Walls.

(5) Remember that MOST of the Head Bolts that SNAP OFF will do so WELL BELOW THE LEVEL SURFACE OF THE ENGINE BLOCK. This means that it will be VERY Critical to be accurate when carefully controlling the use of a Hammer on a Center Punch to Create a Guide Dimple Point that MUST BE MADE DEAD CENTER inTO the Top of the Broken Bolt Remnant. THIS is what getting it WRONG can do to the adjacent Engine Block Metal:


(6) Use High Quality Tungsten-Carbide EZ-Outs. In particular, spend a little more money on Amazon and obtain a High Quality, Ratcheting Square Tap Bit Holder for use in gripping the EZ-Outs and the ARP Thread Chaser necessary for cleaning out all of the Atlas Engine Block Head Bolt Holes. The Cheaper Apparatus will Loosen and FAIL just when you require the MOST Control Possible. Successfully Unwinding these Damaged Bolt Segments requires very close attention to all of these Details.


(7) Start by using a Hand Held Battery Powered Drill with a Small Cobalt Drill Bit *** and Spray the Top of the Dimpled Broken Bolt Shank with some Cutting Oil+++. The important Technique to follow whenever drilling into Hardened or Work-Hardened Steel Bolts is to Keep the Drilling Speed SLOW while applying even downward pressure on the Drill at a Right Angle to the Upper Engine Block Surface.


+++ https://www.amazon.com/dp/B000M8NYIU/?tag=elightbars-20

*** https://www.amazon.com/cobalt-drill-bit-set/s?k=cobalt+drill+bit+set&tag=elightbars-20

(8) Early on with this effort, if the Small Drill Bit is deviating from Drilling Dead Center through the top of the Broken Bolt Shank… STOP… and Re-Punch in a New Dimple with a Larger Hardened Steel Center Punch. Then start all over again with trying to establish a Drill Point that is as Close to Dead Center as possible. The images of the “Tailings” of the Removed Broken Bolts shown below are PROOF enough that even under the WORST of circumstances, re-setting your initial Drill Point WILL be possible and go a long way towards successfully extracting Broken Bolts that are ‘being VERY difficult to convince…’ and coax them all out of the Engine Block.

(9) Work with Short, Controlled Bursts and STOP often enough to keep the Drilling Hole clear of the Drill Cuttings and to give the Bolt Shank(s) the chance to Cool Down. Wear Decent Eye Protection and Gloves and use “Canned Air ” and some Scott “Blue” Shop Towels to drive out and collect the ejected Oily Metal Particles and get them removed from the Work Field.

(10) As you drill down into the Bolt Shanks… when you reach a depth of around 3/8” inside, try using a slightly larger Reverse Drill Bit if you can find one and as the Drill works inwards in Reverse, in many cases, that Counter-Clockwise Drilling Force will be enough to unwind most of the Broken “Tailings”.

(11) But if NOT… Introduce the appropriate sized Carbide EZ-Out and use Steady, Counter-Clockwise Downward Force in order to allow the Bit to “Chew” itself into the Drilled Space and work to unwind the Broken Bolt Shank. “The Better the Tools Are that Get Used… The Better The OUTCOME Will BE!”


(12 Bear in mind that this job requires paying constant attention to all of the details for Each and Every Broken Bolt Stud. The central idea here is to Rescue a rather expensive Engine Block and NOT "Wind Up" making Matters WORSE...

Continued in Part 3 of 3 Parts...


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This is an Important, On Topic, Time Sensitive Update as of Monday, October 12, 2020:

The Majority of the Methods recommended above on Page 2 of 3 regarding Extracting Broken Head Bolts AND Mains Caps Bolts from the GM Atlas Vortec 4,5 and 6 Cylinder Engines can be dealt with more immediately by using the K&M EN-47702 Kit that unfortunately at the present, has scant availability for less than $200 to $400 via the Freedom Racing Company.

However, there ARE still some OEM K&M EN-47702 Kits still available over on eBay in the range of $125.00 that include Two Drill Guides designed to side step the need for difficult alignment portion of this work of having to Center Punch a Guide Dimple and worry about losing the Guidance and Control of the Drill Bits involved during numerous Bolt Extraction Efforts.

I picked just ONE of these Sellers from the group at this next link and after offering (Him&Her) $100.00 plus $9.00 S&H... they accepted and sold me the Kit. So anyone who has the pending need to R&R the Engine Heads and/or Crankshaft Mains Caps on your GM 4.2L LL8 Engines...look into getting this Kit ...Sooner than Later:



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