Head bolts

[IHateHacks]

Yes, ARP studs are superior to ARP bolts but the difference between any ARP hardware and stock hardware is far greater than any difference between ARP studs and ARP bolts.

The block is iron, not steel, and is about the strongest material you can thread a bolt or stud into. But it does have its limits. In my opinion anyone that goes higher than 80 ft/lbs is crazy and just asking for trouble (in the form of stripped block threads). Titanmotorsports says use 75ft/lbs for high boost applications. I believe Toyota reissued a torque spec of 72ft/lbs for stock head bolts, and thats with using 30wt motor oil for lubricant on the threads like the TSRM says. That is the biggest factor when torqueing head bolts, what kind of lubricant you use. ARP comes with moly lube that is the slickest lubricant you can buy, far superior to motor oil. It says right on the package that 85% of torque applied to any dry, unplated fastener is lost due to friction between the male and female threads. With motor oil the loss is lower and with ARP moly lube its far lower than with motor oil. Just to put it in perspective, for a 12mm stud (7M's are 10mm thread size studs) ARP recommends 86ft/lbs with ARP moly, and with the same stud with 30wt oil you would need to torque that stud to 109ft/lbs to get the same clamping force. Thats a big difference. ARP doesn't list a torque value for 10mm thread sized 190,000psi tensile strength bolts (the bolts I used) so I just went with 70ft/lbs. For 10mm studs, ARP recommends 60ft/lbs with moly and 70ft/lbs for 30 wt oil.

[cre]

Factory spec for the headbolts is 58ft lbs with motor oil. http://www.cygnusx1.net/Supra/Librar...ion=EM&Page=55

[IHateHacks]

I SAID they reissued a new torque value and what I meant by "like the TSRM says" is to use motor oil.

I own the TSRM thank you very much. I'm talking about advanced mechanical dynamics here, obviously far beyond your scope of stock head bolt torque. The fact is that 72ft/lbs with motor oil would equal less with ARP moly lube. Thats what I was trying to tell you and I get, "the factory torque spec is 58ft/lbs". We all know that the factory 58ft/lbs is wrong, we don't need a link to the TSRM. I have connections with Toyota dealerships, I get 20% off anything I want along with factory trained technicians to tell me things any other mechanic wouldn't know about, like the reissued torque value.

I think its funny how all these people (sorry supramacist) with non turbo motors are replacing head gaskets with ARP hardware. Those cars should be in the scrapyard. The cost of repairing a head gasket on a non turbo supra far exceeds the value of the vehicle. Shit, even on a turbo motor you are closing in on the vehicles value. Besides, I don't know what you are trying to prove, a stock turbo supra is at best sub par so a non turbo supra is a joke. What a waste of time and money.....