Andy, I torque my rod bolts using the following procedure.
I lube the shank of the bolts with oil where they pass through the rod. I use ARP thread lubricant on the threads and underside of the flange nut to ensure proper & consistent torque values. I torque to 15 ft lbs on each rod bod first. I check for smooth rotation of the crank.
I then torque to 25 ft lbs using a slow & smooth application; never twist fast or jerk the torque wrench. I again check for smooth rotation of the rod on the crank. I use Clevite 77 assembly lube on my engine builds.
I only use beam style torque wrenches to ensure proper torque.
Here's a pic of one of the new con rod bolts on the verniers...
Please do not use measurements of the bolts as any form of criteria is the bolt is good or bad. The bolts are not machined to be used with a stretch gauge. The threads are rolled and the tip of the bolt is very inconsistent. The Y on the head can also vary significantly on height.
Proper torque is how the bolts are designed to be used.
APE used to sell replacement ARP bolts and nuts for the FJ....much better than stock pieces. You could call them about them.
The ARP bolt were for the FJ, but they were not a direct replacement. The shoulder of the bolt is larger than stock and requires the rod to be bored or reamed to get the bolts to fit. I only used the ARP bolts a few times and frankly they were not worth the investment. So, I quit using them back in about 97'-98'
The stock bolt is fine and used in 1000's of FJ engines powering race cars all over the world. They are not a weak part/spot of the engine.
And finally, in the last 25 years of building this engine, I cannot for the life of me remember a time where I ever had a rod bolt stretch and break while torquing. If the bolt stretches and breaks while torquing, then you have a wrench issue.
Randy - RPM
