pittbull7934 said:
Also on the head gasket, I was using the higher torque specs because I did not use arp's assembly lube, but motor oil (I called arp and they recommended this) I have decided since I pulled out the threads with the higher torque specs that i am going to buy the arp assembly lube so i can run the lower torque specs.
If i reuse the head gasket is there going to be a issue since i will be torqing the heads down with less torque than i did on the first attempt?
ARP steered you wrong, their lube and oil should be torqued the same spec as oil, but the Chevy has a lot of bolts that pass into the cooling jacket, they need a sealer not just lube. I and bunches of other guys use plane old Teflon plumbers pipe joint paste with factory torque specs on the head bolts, this insures coolant doesn't get up the threads causing corrosion in the threads if not leakage from the bolt head. Remember to lube under the bolt head or if using hardened washers under the washer as well.
The general problem with torque specs is it's a secondary means of measurement about what you're trying to accomplish. Your trying to take the fastener to the edge of it's yield point which is intended to insure that the clamping load on the fastener is greater than the working load of the parts it's holding together, otherwise the fastener will back out and loosen its clamping force. Torque is a measure of the force required to get the fastener into this plastic deformation state and is arrived at by testing how much force needs to be applied to stretch the bolt into its yield curve. Unfortunately, torque is also a measure of those things that affect friction between the threads of the fastened and the fastener, so condition, cleanliness, and quality of the threads count, as does lubrication. Also the friction that develops between the seating surface of its head and the item being clamped, so lube needs to also be under the head of the bolt or nut being used. So torque can vary all over the place compared to the actual forces trying to stretch the bolt.
One of the problems you get into with high strength fasteners is that the OEM engineers design the fastener they use to fail before the threads in expensive items like engine blocks. When you go to aftermarket fasteners, you will find them to be stronger than the material they are threading into, so when an over force event happens it's items like the engine block that fail before the fastener. In my opinion, unless your building a race engine that needs to take all the potential strength the castings have, the use of extra strong fasteners for non racing applications is a lot like spitting into the wind, eventually you're going to be left with a good but relatively inexpensive to purchase bolt and an expensive to repair or replace busted casting.
Bogie
