Head Bolts

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Feb 17, 2006 | 09:00 AM

ksaieg78

Thread Starter

Heel & Toe

Joined: Jul 2005

Posts: 22

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From: JOLIET IL

Head Bolts

I'm In The Process Of Re Installing My Freshly Ported Ls6 Heads And Am Wondering If It Is In Fact Necc. To Replace The Head Bolts???? If You're Not Sure, Or Have Only Heard That
They Need To Be Replaced Please Don't Reply I Would Like To Know For Sure. What Do They Do At The Dealer???? Do They Replace Them????

Feb 17, 2006 | 09:12 AM

vettenuts

Team Owner

Joined: Mar 1999

Posts: 22,025

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From: At the beach in little Rhody

Yes, you have to replace them. The Service Manual has a big warning on re-using them. The way they are tightened, to ensure proper preload, is to twist through an angle rather than a torque value.

Feb 17, 2006 | 09:32 AM

Bill Curlee

Tech Contributor

Joined: Dec 1999

Posts: 32,910

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From: Anthony TX

CI 6,7,8,9,11 Vet

St. Jude Donor '08

It is a FACT, that the head bolts MUST be replaced!!!! They are a Torque to yield bolt and designed to be a ONE TIME use fastener. Don't try to use them. They are inexpensive and easy to get.

They need to be torqued to 22 ft/lbs and then angle torqued to the correct degree.

If you reuse the old ones the angle torque specifications will not provide the correct clamping forces to work properly.

BC

Feb 17, 2006 | 09:59 AM

vettenuts

Team Owner

Joined: Mar 1999

Posts: 22,025

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From: At the beach in little Rhody

Here is a basic article that will provide you some backgroud on the reason they are TTY for preload.

Enjoy

TTY Fastener Article

Feb 17, 2006 | 10:11 AM

ArKay99

Safety Car

Joined: Sep 2003

Posts: 3,558

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From: Cape Coral FL

Also, I don't know if you are aware of this so I'm bringing this to your attention. The bolt holes have to be squeaky clean. No dirt, No coolant, no threadlock, from the uninstall. If the holes aren't cleaned perfectly, you will probably cause a hydrolock in the holes and crack your block. Let me refer you to this article on the way to do this properly. Head re-install . Scroll down to the section on prepping the block decks and bolt holes. It's really easy, just takes a little time, but prudent.
Best of luck.

Feb 17, 2006 | 01:43 PM

Jim Taylor

Pro

Joined: Aug 2000

Posts: 517

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From: Arlington Texas

Also, the dealer will gouge you for the ten main bolts, $6-$8 per bolt!

Buy them from your local auto parts store or from an online parts house for $20-$25 per head. Same thing with the gaskets.

Feb 17, 2006 | 03:31 PM

IFLUBYU

Drifting

Joined: May 2003

Posts: 1,715

Likes: 1

From: cAshburn VA

Yes it is a fact, you cannot reuse torque-to-yield bolts, which the factory ones are. I'd recommend replacing them with ARP bolts or studs, which are reusable. Very good point on cleaning the bolt holes, also you do not get accurate torque readings if there is dirt on the threads.

Feb 17, 2006 | 03:36 PM

Heretic

Pro

Joined: Jun 2003

Posts: 702

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From: Castle Rock Co

Quote:

Originally Posted by Jim Taylor

Also, the dealer will gouge you for the ten main bolts, $6-$8 per bolt!

Buy them from your local auto parts store or from an online parts house for $20-$25 per head. Same thing with the gaskets.

I'd pay the dealer price before I bought parts store junk. Beans has them for cheap though.

Also there is option B which costs a bit more, but is the best option. ARP bolts. I will never ever buy anything else after having a GM head bolt break at its specified torque while building a BBC.