>>>*Morning!

*Quite a discussion. We always replace the head bolts on the 3VZE, mostly because of early on we had two cases of breaking them. This spoils a day quickly...

*Ever notice it is nearly always either the last one or the next to last one?...*LOL**

I personally won't make the studs, I do not own the equipment to roll the threads during the forming process. Sure, I could set up and cut the threads, this is much weaker than a formed and rolled out piece. *More work, too and I'm lazy.......All it takes is one little stress riser and the stud can break.

Usually breakage with bolts is due to the threads creating resistance, they stop turning. The same can happen with a stud if the nut end threads are not completely free and lubed. Once they stop slipping as they are torqued, you are now twisting the shaft of the piece. I have had a couple of cases of folks breaking brand new bolts, this is the cause of that.

If the shaft of the fastner is actually twisted rather than tightened into the block, it is not creating clamping force at all, even though the torque wrench may read accurate load.

Yep, it can break. So before we even think of going to maximum torque, we clean the threads in the block with a chaser, (NOT a tap)..Then we oil the threads and spin the bolt all the way in and out with our fingers. This assures they are clean and lubed.

Then we pull them to 50%, all of them. ... back off 1/4 turn and repeat, note each time it will turn a tad more before 50% is reached. This is because the threads are bedding in. We do this 5 times, then we go to 75%, then to 100%, all done. We do this with ALL new fastners...it assures a more even clamping force, inconsistant clamping force is the number 2 cause of early head gasket failure..(heat is number one)

It takes some time, sure, but it takes less time than pulling the head back off...Hope this helps.....*EB