What torque for HKS headgasket and ARP studs

[240Z Turbo]

Preloading on the block side to cancel forces does not make sense to me. If you torque the studs in the block, bottoming it out, you exert force on the top side of the stud threads and the bottom side of the block threads. This is the same thing that happens when you torque the nut on the stud. So you have effectively now placed additional stress on the threads. Remember, the amount of threads needed is 1.5xstud diameter or 1.5x10mm=15mm. That means the stud only needs to go into the block 15mm before there are enough threads to adequately hold it. So why the need to preload the studs, just put them into the block as far as they will go hand tight and you have enough threads to hold it. Maybe I am off my rocker and could be wrong in my thinking.

[TimZ]

I must admit it's a bit fuzzy to me, too. I'll try to find the info and re-read it, and see if it makes any more sense.

[Guest norm[T12SDSUD]]

Dude, make sure you drain the water out of your engine if you plan on loosening more than one nut at a time. There was a guy on the Zforum once that loosened a few too many head bolts and didnt find out he had leaked water into the cylinders until he cranked the puppy. Water doesn't compress and the guy ended up toasting one of his connecting rods!

Good luck. Its amazing that we can put men on the moon but can't get a compant to get their darn torque specs right!!

[Evan Purple240zt]

Whoa, good tip norm!

 

Thanks= Evan

 

PS... scary never thouught of that!!

[240Z Turbo]

Huh? Why do you care if it is hand tightened. Because it is a stud, you gain additional clamping force with the finer thread pitch on the torqueing side. These studs go further into the block than the stock head bolts which alone gives you more ability to gain clamping force.