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need to know torque specs????


jeff983000gt
01-08-2007, 01:00 PM
hey guys..i need to know my torque specs for the head bolts..if it makes a diff..its a sohc..

Igovert500
01-08-2007, 01:52 PM
Don't have manual with me, but I believe ~90ft/lbs. And I know you have to tighten and loosen then retighten, etc, in 3 stages to get them right. Although I don't know the exact method off the top of my head.

jeff983000gt
01-08-2007, 02:27 PM
i see..well there have been conflicting arguments about what it is..if you have the manual can you please look it up? i dont have a manual..if anyone knows exactly what it is and what the 3 stage method is..please let me know..thanks..

Linebckr49
01-08-2007, 02:29 PM
photobucket is slow, so i'm having trouble uploading the pic from the manual. basically, for a non-turbo DOHC engine, the torque spec is 80 ft-lbs. for Turbos, the torque 90 ft-lbs
(1) tighten in "two to three stages in the illustrated sequence.
(2) back the bolts off once (or twice) and tighten them to the specified torque in the same procedure as shown in step (1).

intake
----------------
| 8 4 1 5 |
| 7 3 2 6 |
----------------
exhaust

jeff983000gt
01-08-2007, 02:31 PM
i have a sohc though..is there a difference?

Linebckr49
01-08-2007, 02:47 PM
i didn't include the SOHC specs in the cut&paste pic below, but i checked the manual, and the tq spec for the SOHC head bolts is 80 ft-lbs. apparently, you don't have to tighten, back off, tighten the head bolts for the non-turbo motors. however, if you want to do it in 2 stages, you can. it can't hurt.

http://i57.photobucket.com/albums/g236/Linebckr49/3000GT/headtorquespecs.jpg

sLADe781
01-08-2007, 08:57 PM
Why would you have to tighten, untighten, tighten, untighten, etc etc? What does it do that a regular tightening wouldn't do!?! Sorry if it's a stupid question... Hehe

Igovert500
01-08-2007, 10:13 PM
It covers the chance of anything stretching/shrinking, etc. If the last few threads stretch or if tey bite into the metal etc. It ensures that they end up at say 80ft/lbs instead of say 75ft/lbs. At least that is how I've always understood it. I know I read something a few years ago about how if just tightened down to spec the first time, it can be a few ft/lbs less than spec. Plus by backing them out in that order, and retightening them, you ensure a completely flat seal, because you don't want a head gasket leak later on. That is basically the reasoning behind it that I've always heard.

Linebckr49
01-08-2007, 10:13 PM
all i can say is "that's what the manual says."

i can only speculate that the tighten-loosen-tighten process better ensures a complete seal the 2nd time it is tightened. also, note that there is a special sequence in which you should tighten the bolts. this sequence traces the path of an outgoing spiral. namely, the head must be tightened from the inside out.

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