Shop Line - Engine Builder Magazine

Shop Line

The AERA Technical Committee says the following information should be considered any time a cylinder head is installed on 2001-2005 GM 8.1L VIN E and G engines.

Three different length mounting bolts are used to secure the cylinder heads for these engines as shown in Figure 1. These bolts are intended for a single-use and must be replaced once removed.


Do not reuse the cylinder head bolts. New cylinder head bolts must be used. The cylinder head bolts are torque-to-yield bolts and cannot be reused once the initial torque is applied. During the initial torque of the cylinder head bolt, the cylinder head bolt is stretched to achieve proper clamp load, which will not be achieved if a used cylinder head bolt is torqued again. A stretched cylinder head bolt can also break when torqued. Failure to replace the used cylinder head bolts with NEW cylinder head bolts can lead to improper clamp loads and extensive engine damage.

Sealer is also required on the bolt threads prior to installation. Two different head gaskets are also required. The left side is available as p/n 12580691 and the right side is p/n 12580692.

The sealer must be applied to a minimum of eight threads starting at the bottom point of the cylinder head bolt. If a pre-applied sealer is not observed on the new cylinder heads bolts, apply sealant (GM U.S. p/n 12346004, Canada p/n 1095348O or equivalent) to the cylinder head bolts.

Install cylinder head bolt using the following bolt tightening sequence. The final angle tightening sequence of the cylinder head bolts varies depending on the length of the cylinder head bolt.

Failure to angle tighten the specific length bolt the proper number of degrees can lead to cylinder head bolt failure or improper clamping load of the cylinder head gasket. Cylinder head bolt or cylinder head gasket failure can lead to extensive engine damage.
The long bolts are used in locations 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16 and 17. The medium length bolts are used in locations 15 and 18. The short bolts are used in locations 4, 5, 12 and 13.


Tighten the cylinder head bolts in the sequence shown in Figure 2.

  1. Tighten the cylinder head bolts a first pass in sequence to 22 ft.lbs. (30 Nm).

  2. Tighten the cylinder head bolts a second pass in sequence to 22 ft.lbs. (30 Nm), then rotate an additional 120° using J 36660-A (electronic torque wrench).

  3. Tighten, in sequence, bolts 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16 and 17 an additional 60°.

  4. Tighten bolts 15 and 18 an additional 45° and bolts 4, 5, 12 and 13 an additional 30° for a final pass using J 36660-A.

For information on receiving all of AERA’s regular monthly technical bulletins and other association services and benefits, call toll free 888-326-2372 or send an e-mail to [email protected].

You May Also Like

Brand Loyalty – is it a Thing of the Past?

Well folks, it’s late September and summer has officially come to a close. If you’re like me, you’ll miss those warm weather days and longer hours of daylight, but it’s been a great few months of race events, car shows, seeing customers, visiting shops, and of course, creating tons of content. In fact, one of

Well folks, it’s late September and summer has officially come to a close. If you’re like me, you’ll miss those warm weather days and longer hours of daylight, but it’s been a great few months of race events, car shows, seeing customers, visiting shops, and of course, creating tons of content. In fact, one of those content pieces that will be big for us this fall is Engine Builder’s Dream Engine Giveaway – a twin-supercharged 427 small block Ford we are building with Chris Wright of Pro Car Associates / MVT. You can enter to win this engine here: . We’ll be sharing updates via our website, YouTube and social media channels as we get the build done in time to be given away at PRI in December. But, all of that is for another time.

Engine Builder Attends SBI’s 40th Anniversary Gala

If there’s anything that these past couple years has demonstrated, it’s that nothing is for certain in life or in business. In these days of such ever-changing environments, economies, consumer habits and the like, it’s more than impressive when a company reaches a major milestone. In July, the team at S.B. International, located in Nashville,

SBI Gala
Summer Vibes and a Dream Engine Giveaway

How can you not love summer? Sure, it gets hot, but it definitely beats the cold, and there’s so much going on to occupy your time. Here at Engine Builder, our team has stayed extremely busy attending racing events, shows, visiting manufacturers and engine shops, as well as our usual content work.

Think You Got What it Takes to Brawl?

First things first, I’m not referring to a fist fight, but I’m sure most of this crowd could hold their own. Rather, I’m referring to a new drag race event called Builder’s Brawl.

Passion Runs Deep

Having had the distinct opportunity to view this industry from my chair as editor of Engine Builder has certainly opened my eyes to a lot of great things this industry has going for it. However, my favorite thing about it – hands down – is the passion. Related Articles – PRI 2021: What a Show

Other Posts

Experience Always Wins

Formula 1 racing often tells smaller stories within each individual race; the final stretches of the Russian Grand Prix proved in my eyes that experience always wins.

Should Driving Be Outlawed by 2050?

As the world changes, so too does the automotive industry. Will self-driving cars eventually take over?

Male or Female – Passion Fuels Our Industry

Whether you’re a man or a woman, you can relate to that feeling this industry gives you and you want to immerse yourself in it. That’s what makes this industry great.

Ed Iskenderian of Isky Racing Cams Celebrates 100

July 10, 2021 marked the 100th birthday of Isky Racing Cams founder Ed Iskenderian. The man is an icon in the industry.