LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Changing my head gasket.. couple q's

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Old 12-07-2010, 01:18 PM
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Re: Changing my head gasket.. couple q's

TTY is NOT a method. It is a procedure that is proper for a SPECIFIC type of bolt. You would not use the Torque Angle TTY method on a non TTY fastener.

On a non TTY fastner you would use torque specs or a stretch gauge if possible.

There is so much engineering that goes into a torque spec or a tightening sequence that we should not question it unless we are the engineers that have designed the engine or part. Things like gasket compression, bolt stretch, compensation for disimilar metals (aluminum head on iron block), etc. Sure we understand the concepts, but we shuold not question them or modify them.

RTFM! :-)
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Old 12-07-2010, 05:53 PM
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Re: Changing my head gasket.. couple q's

Originally Posted by PWR SHFT
TTY is NOT a method. It is a procedure that is proper for a SPECIFIC type of bolt. You would not use the Torque Angle TTY method on a non TTY fastener.

On a non TTY fastner you would use torque specs or a stretch gauge if possible.

There is so much engineering that goes into a torque spec or a tightening sequence that we should not question it unless we are the engineers that have designed the engine or part. Things like gasket compression, bolt stretch, compensation for disimilar metals (aluminum head on iron block), etc. Sure we understand the concepts, but we shuold not question them or modify them.

RTFM! :-)
It should also be clarified that TTY is NOT the same as the TAA (torque-angle method) of tightening.
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Old 12-08-2010, 07:14 AM
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Re: Changing my head gasket.. couple q's

Originally Posted by RamAir95TA
It should also be clarified that TTY is NOT the same as the TAA (torque-angle method) of tightening.
Partially true. I found a great website to end the myths. Interesting what they say about Angle Controlled Tightening vs. Yield Controlled Tightening.

http://www.boltscience.com/pages/tighten.htm
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Old 12-08-2010, 08:25 AM
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Re: Changing my head gasket.. couple q's

Wow, never thought I would start a pissing match by expressing my opinions and things that I have learned. Guess from now on I should only chime in if i'm an expert, which I obviously am not. Most of the time, common sense works for me, it always has.
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Old 12-11-2010, 05:47 PM
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Re: Changing my head gasket.. couple q's

Originally Posted by shoebox
You're pretty awesome if you can eyball 67 or 80 degrees with a paint mark. Do you eyeball bearing clearances, too?



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Old 02-12-2011, 05:32 PM
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Re: Changing my head gasket.. couple q's

Soooo... just to be clear.

Torque in proper pattern to proper torque.

Then turn additional angle. Just plain old 67 (or 80) degrees. As long as you can accurately measure the angle in degrees, that's what counts.

Right?

(I know the stinkin gage is only $20, but I want to finish this tonight and I can measure degrees with my drafting tools...)
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Old 02-12-2011, 09:47 PM
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Re: Changing my head gasket.. couple q's

Originally Posted by 350350
Soooo... just to be clear.

Torque in proper pattern to proper torque.

Then turn additional angle. Just plain old 67 (or 80) degrees. As long as you can accurately measure the angle in degrees, that's what counts.

Right?

(I know the stinkin gage is only $20, but I want to finish this tonight and I can measure degrees with my drafting tools...)
http://shbox.com/ci/head_assy.jpg
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Old 02-12-2011, 10:36 PM
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Re: Changing my head gasket.. couple q's

Originally Posted by shoebox
Oh Jeebus, here we go...

I can and am happy to do it either way, honestly. I'm with you that the Torque+Angle is better.

From the photo above, it sounds like the only difference is the bolts? 93-95 use 'traditional' head bolts?

I have a '97. My factory service manual says the 'second half' of what shbox's pic/link above says. So my manual says what shbox says. Which doesn't surprise me at all. Cuz shbox rox!!!

Now here's my dilemma. I bought replacement head bolts at the parts store, and they gave me Fel-Pro set ES72856 which says (in summary) Small block engine 1955-1996 and Chevy truck V8 1955-1998.

So do I torque them as in the 1996 method in shbox's pic, or do I Torgue+Angle them like the 1997 in the pic says?

Or do I start over (already have them torqued to 22ft-lbs awaiting next step) and make sure I get 1997 bolts?

I'm too exhausted to make this kind of decision tonight. I'll sleep it over while all you night owls pour over every ounce of available research and report back asap! There's a shiny nickel in it for each and every one of you!!!

P.S. It took me 6 months to scroung enough $$$ to just put the effin thing back together stock. I just want it to make boy racer engine sounds when I turn the key. It's stock stock stock. No turbo. No nitrous. Just stock.
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Old 02-12-2011, 10:55 PM
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Re: Changing my head gasket.. couple q's

Originally Posted by 350350
Oh Jeebus, here we go...

I can and am happy to do it either way, honestly. I'm with you that the Torque+Angle is better.

From the photo above, it sounds like the only difference is the bolts? 93-95 use 'traditional' head bolts?

I have a '97. My factory service manual says the 'second half' of what shbox's pic/link above says. So my manual says what shbox says. Which doesn't surprise me at all. Cuz shbox rox!!!

Now here's my dilemma. I bought replacement head bolts at the parts store, and they gave me Fel-Pro set ES72856 which says (in summary) Small block engine 1955-1996 and Chevy truck V8 1955-1998.

So do I torque them as in the 1996 method in shbox's pic, or do I Torgue+Angle them like the 1997 in the pic says?

Or do I start over (already have them torqued to 22ft-lbs awaiting next step) and make sure I get 1997 bolts?

I'm too exhausted to make this kind of decision tonight. I'll sleep it over while all you night owls pour over every ounce of available research and report back asap! There's a shiny nickel in it for each and every one of you!!!

P.S. It took me 6 months to scroung enough $$$ to just put the effin thing back together stock. I just want it to make boy racer engine sounds when I turn the key. It's stock stock stock. No turbo. No nitrous. Just stock.
PPS... the Fel-Pro bolts *look* identical to the original bolts in every way. Completely exactly the same.
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Old 02-12-2011, 11:55 PM
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Re: Changing my head gasket.. couple q's

I used ARP bolts on my heads. I torqued them to 65ft-lbs, following the torque pattern, in three steps... 25, 45, 65.

No problems so far. Just use a little oil under the washers and bolt heads. Also, don't forget to put thread sealant on the threads(don't be shy with the amount....I used a liberal amount...in my opinion, better too much than not enough for this job). I used permatex's high temp thread sealant....zero leaks.

Be sure you chase all the bolt holes with a chase...the holes need to be clean and dry for the install.

Last edited by ACE1252; 02-13-2011 at 12:02 AM.
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Old 02-13-2011, 08:33 AM
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Re: Changing my head gasket.. couple q's

Originally Posted by 350350
PPS... the Fel-Pro bolts *look* identical to the original bolts in every way. Completely exactly the same.
If the bolts have the integrated (not loose) washer (assuming your original bolts were like this), use the t/a method.
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Old 02-13-2011, 09:08 AM
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Re: Changing my head gasket.. couple q's

Originally Posted by shoebox
If the bolts have the integrated (not loose) washer (assuming your original bolts were like this), use the t/a method.
Awesome, I Love You! (But not with the ghey.)

K Ima make a torque/angle guage out of a protractor now. I KNOW you guys wanna see it when I'm done!!!

[voice of that guy from that movie]"Gauges? We don't need no stinkin' gauges!!!"[/voice of that guy from that movie]

And ACE I'm starting to think it would just be easier to steal your car... Mine's all stock and in a million pieces and stuff...
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Old 02-13-2011, 05:06 PM
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Re: Changing my head gasket.. couple q's

OK so all done easy breezy.

I wanted to x2 what others already said here about marking the bolt heads before you do the +angle part. Otherwise you don't really know if you got them all or not.

Also, just out of wild curiosity, I went back over all of them with the torque wrench when I was done doing the +angle part. I set the torque wrench at 65 ft-lb and all but 2 bolts were more than 65 ft-lb after the +angle procedure. 2 of the bolts were less, 2 of the short ones, and I went ahead and torqued them to 65 which amounted to about 10 more degrees of angle beyond 67 degrees.

Meh. I took a bunch of pictures of the angle gauge I made and the bolt heads marked before and after +angle if anyone wants to see them.
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Old 02-13-2011, 08:05 PM
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Re: Changing my head gasket.. couple q's

Slight hijack, same topic.

I recently rebuilt my motor (95 z28), but after initial oil change I have chocolate milk colored oil so I suspect a blown head gasket. 20 miles max of drive tiime.

First, is it possible the culprit is not using the correct torque sequence? Is the sequence the same as gen I motors? The reason I ask is I am not sure how much experience my machinist has with Gen II motors.

Second, can I re-use the ARP bolts with only 20 or so miles on new setup?
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Old 02-13-2011, 10:59 PM
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Re: Changing my head gasket.. couple q's

Originally Posted by Larsv8
Slight hijack, same topic.

I recently rebuilt my motor (95 z28), but after initial oil change I have chocolate milk colored oil so I suspect a blown head gasket. 20 miles max of drive tiime.

First, is it possible the culprit is not using the correct torque sequence? Is the sequence the same as gen I motors? The reason I ask is I am not sure how much experience my machinist has with Gen II motors.

Second, can I re-use the ARP bolts with only 20 or so miles on new setup?
I hate to hear that. If I'm not mistaken, you should be ok to reuse the ARPs. The torque sequence seems to be the same.

SBC
http://boxwrench.net/specs/chevy_sb.htm

LT1 - from Shoebox above....
http://shbox.com/ci/head_assy.jpg
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