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according to the haynes manual you should install the hgasket by torquing to 20+ ft/lbs...then 40+ ft/lbs....then loosen everything, and torque a final time up to 47 ft/lbs...

why do you have to loosen it, and then torque it again? If you don't do this, will the gasket leak from the begininng? this is related to my compression problem posts in this forum....i didn't loosen the bolts like the manual said, i didnt think it mattered
 

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I'm assuming from the figures your using, that you are talking about a VG30, correct?

To my knowledge, the reason for the multiple torquings is to "bed in" the gasket, and avoid having to retorque the headbolts later on, or to avoid having them "relax" later on, and so causing a headgasket failure.

Pay particular attention to the fact that both the Haynes and any FSM you might be using calls for the bolt threads and washer bottoms to be lubricated, this changes applied torque dramatically, much different from simply torquing the bolts dry. Right off the top of my head, lubricating the bolt threads reduces indicated torque by 30% or so at the same tightness where it would read on the wrench if the threads were dry. So applying 40 lbs of torque to lubricated threads should get you about the same results as say, applying 60 lbs to dry threads. (Just used for explaination, that's not an accurate conversion)

It's all a system and it all works together. Leave too many parts out and your engine is doomed to early failure.
 
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