reinstalling heads

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Oct 9, 2009 | 12:42 PM

ol school

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Pro

Joined: May 2006

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From: Humble Texas

reinstalling heads

QUESTION !
Im reinstalling my heads this weekend, IS IT REQUIRED TO REPLACE THE ORIGINAL HEAD BOLTS??

Oct 9, 2009 | 01:12 PM

CFI-EFI

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From: The Top of Utah

Historically, no. Some of the newer engines with "Torque To Yield" (TTY) head bolts should be changed every time they are torqued. Not so with a conventional Gen I, or Gen II, SBC engine. The factory SBC head bolts are good for several reuses. If you feel them stretch or they feel spongy, replace them. Also, make sure the threads are clean, both on the bolts and in the block.

RACE ON!!!

Oct 9, 2009 | 05:06 PM

pr0zac

Melting Slicks

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From: Pittsburgh Pa

Quote:

Originally Posted by CFI-EFI

not exactly true.. 96-97 lt1's and lt4's had torque to yield bolts.. you need new head bolts

Oct 9, 2009 | 07:56 PM

ol school

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Pro

Joined: May 2006

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From: Humble Texas

Quote:

Originally Posted by pr0zac

not exactly true.. 96-97 lt1's and lt4's had torque to yield bolts.. you need new head bolts

Hmm well there seems to be a conflict of opinions on weather to replace
the head bolts, I just picked up my heads from the machine shop,he
didnt think i needed to replace them,but because ive heard two differant opinons, ive decided to replace them i figured at $35.00 was a small price to pay .... hoping to install tomorrow

Oct 9, 2009 | 08:52 PM

Midnight 85

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From: Hellinois

Finalist 2020 C4 of the Year - Modified

I was told my '85 had TTY bolts and I figured what the heck I've re-used head bolts lots of times. I had done the entire torque sequence three times and on the last bolt of the last sequence the dirty sob broke. You made the right move getting the new headbolts. If they are ARP, be sure and use the washers and the lube that comes with them, if they are another brand then 30 wt. motor oil will work as a lube.

Oct 10, 2009 | 02:24 AM

CFI-EFI

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From: The Top of Utah

Quote:

Originally Posted by pr0zac

not exactly true.. 96-97 lt1's and lt4's had torque to yield bolts.. you need new head bolts

If that is true, I have learned something new today. I know TTY head bolts to be bolts that have a torque spec of so many ft.lbs. of torque, plus a given number of degrees of rotation. I was not aware any of the LTx engines had TTY head bolts, in any years. I also didn't know that the 1997 was a C4 or that it had an LT1 or LT4 engine available. Had the OP specified a year, my initial answer might have been somewhat different. I stand corrected. Thank you.

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Oct 10, 2009 | 04:41 AM

93 ragtop

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From: Manassas VA

Look at a service manual and see what they say the torque setting is. As I had posted earlier, they changed to the torque to yeild bolts. ( I called them stretch bolts :o) in the latter model LT1.
But if the torque for your car shows something like torque to 15lbs, then turn each 1/4 a turn etc. Do not reuse those bolts.
Most people I know, replace the bolts with ARP head bolts, and then use the earlier torque settings.