I'm freshening up my 572 Hemi,it has 7.100 Molnar rods withARP 2000 bolts that have probably been torqued 5 times between checking bearing clearances and assembly using the torque plus angle method with a Snap-On torque wrench. I never measured the bolts when they were new but this time I bought a point micrometer to measure them and they are all over the place, with up to 0.006difference from shortest to longest free length.Are some bolts stretched or do the free lengths vary that much.Has anyone measured theirs when new?

Yes my new bolt lengths were all over the place

same here.

Mine were torqued but never run before I checked them. Using a micrometer my bolts varied 1.933 - 1.928 most hovered around 1.930 (same rod and bolt you are using.)

If you have any questions call Molnar I've been talking to Ed. He's been a really big help.

yes they will vary, mine did, I always measure each one in a free state and then mark it down the tighten them untill you get the reccomended stretch which with mine were .00055 to .00060, you will be suprised what the torque will end up being

Mine were all over the place. Between 5 and 7 from what I remember. What I found was that if you torque per Molnar direction using a degree scale, the torque would end up in the 75lbft range torqueing just using a torque wrench. I just used Toms direction for torqueing the rod bolts and everything went well.

Can I ask what Tom's directions were

I went out and measured my NEW, in the bag, Molnar/ARP 2000 rod bolts. Never been installed or torqued. Shortest one at .000", longest one at .009", with the others some where in between. These are to replace the ones currently in use with over 4 1/2 years of mostly 1/4 mile runs. The original bolts, when new, were with in approx. .0015" with two exceptions, but they all had been torqued at the factory (at least one torque cycle). When freshening the engine this spring, I found that these bolts were now all over the place, hence the new ones for replacement. I also found that to get the proper stretch, the torque (w/ the proper lube) was over 75 ft lbs, closer to 80. When using the "torque and turn 60* method", the bolts were stretched more than the .0062" limit.
On a side note, I installed a set of Bill Miller alum rods last year, (high $$$$) and Bill himself told me not to worry about stretch, lube and torque them and run the h*** out of them. Like most on here I have torqued rod bolts in HP engines for many years with zero problems, never even heard of a stretch gauge. But whatever, I can follow the rules...

Brian

I think it was 30lbft then clock 60*. I will look at my notes.