Thanks.
I am a victim of myself. I read or hear of a better way to do things that I have been doing successfully for years and feel compelled to at least try the "better way" . It almost always ends up this way or with no better results. Something in me has really changed with age. When I was 20 30 years old I knew everything and all was well in my mind . Now I seem to doubt and question all I do.

Eagle recommended just checking the bore once new bolts are installed and torqued . Again he felt it would be ok .

8740/2000'S 7/16 rod bolts stretch to .005-.0055 in the 75-85 lb area in my experience. That's where I stop.

Just called Eagle to order two new bolts. When I had him on the phone I started asking questions about measuring the bolt stretch . He stopped me and said they do not do it that way and dont feel its necessary .
Said use their lube , torque both to 25 then, to 63 in one motion .

I am now running into the woods screaming and ripping my hair out!!!!!!

It just never ends.

Had the same problem the ARP lube you are using is not good for rod bolts.
Molnar sends the Extreme pressure lube #3 with their rods because the arp lube cases friction under extreme pressure you are putting them under that's why the torgue is so high
when I use the #3 lube torque and stretch fall within +- 10 lbs to spec
summit part number
https://www.summitracing.com/parts/hrs-99008

I think angle torque is the only way to accurately stretch the bolt without using cumbersome gauges. It removes almost all of the variables, doesn't care about wet threads, dry threads or type of lube. The only witchcraft in it is establishing where "zero" is. X number of degrees from zero is always .00X" of stretch.

As an example, Caterpillar 3406 rod bolts are torqued to 70 ft/lbs + 90 degrees. The mains are 200 ft/lbs + 120 degrees.

Kevin

I have to disagree with this method. I tried it and the it often requires a different amount of torque to get the ideal stretch. Friction is a huge issue. Especially when trying to sneak up on stretch. getting the bolt/nut moving again once the torque is over 70 takes a good deal of effort, well over the number you started with. If the torque gets it to .006" stretch. Then try to get it to .0065", not easy.
Doug

I don't know. It seems there are different methods to do this and they all make sense until someone points out what is wrong with the method.
What doesnt make sense to me is in this day and age of technology a company like ARP doesnt know that if they torque a given bolt to xxlbs that it will stretch between .xxxx and .xxxx ? if they dont know this where are they coming up with the torque spec? And if its so uncertain why even offer a torque spec?
e gads

You're correct it ends up to some where around that number. Torque is a estimate of stretch/friction. That's why the lube makes a HUGE difference. Now combine that with machining process of the threads and you get an estimate. That's why the use of stretch gauges was initiated. To get a better result. I have found a few things about torque in my engine build experience. Multiple short range pulls (20, 40 ,60, 80) are less accurate than a few long pulls (20, 80). After torquing if the fastener is loosened and retourqed in one pull the wrench will generally rotate further the 2nd time. Try it when doing a head gasket. You'll be amazed at the difference.
Doug

It’s kinda funny that guys raced for probably over 50 years using rod bolt torque as the “go to method” of building race engines. Now we are stretching bolts to a given length. Well one guy above said he torque cycles his bolts three times. Well then I’m guessing he installs a bearing and torques it to check rod bearing clearance. If he’s lucky it’s right but if not it’s taken apart to get the right bearings. Then it’s torqued again. This time hopefully it’s dead nuts on so we bolt the engine together. Ohhh damn the Stroker engine rod is hitting the block so we take it apart to clearance the block and assemble it again. All the sudden those new rod bolts have been torqued 3,4,5,6 times. We every bolt has a life and you just used a bunch of them. Just something to sleep on. If you can.

When I first started using ARP rod bolts in stock 440 rods the instruction said to torque, torque them to the torque spec three times with the lube and untighten them three times BEFORE using a stretch gauge
All the ARP rod bolt instructions sheets I have show different stretch lengths for the 7/16 rod bolts depending on the under head bolt lengths
No matter what not all bolts, even made by ARP, are exactly the same and equal on torque needed to stretch them exactly the same

All the aluminum rods I have dealt with were oil only...NO special lubes. On steel rods I always use arp paste with a little oil...

This is fact.

I just got done proving it to my self. Original Molnar ARP2000 bolts that came with the rods go to 85'lbs to get 0062 torque. I ended up having to order two new rod bolts because using the torque angle method I over stretched the fist two I did... (long story) So after I screwed up the bolts, I knew I wasn't going with T/A.....So I ended up going with finding the torque that equaled the stretch tolerance (0060 - 0064) The guy I talked to at Molnar Monday said I was doing it right by doing it this way.

With this being said the new bolts I got in only take 82'lbs to get the bolt to stretch to 0062. If I use the 85'lbs the stretch goes to 0065+ I can only attribute this to the possibility of these new bolts coming out of a different "run".

So what has been working for me is sneaking up on the proper stretch by torquing the bolt incremental until you get with in the published tolerance.
Call the bolt manufacture or rod manufacture who ever the bolts come from and get their opinion. Molnar has been super helpful, spent 20 min on the phone with me talking about bolt tech.

Molnar said you won't over cycle the bolt by doing this. We can tighten and loosen the bolts as much as we need to. It's the pull force when running that stress the bolts.

That's why I'm logging my over all length's of the bolts so I have a base line to go by.

This is my 2 cents .... not sure it's worth it or not.

I go in 5 lbs. torque increments in increasing every ARP rod bolts I test now, one smooth pull to 45 lbs. now and then back it off and see what 50Lbs. measures and go from there, Sneak up on it 5 lb. at a time This method is time consuming but what effort with good results isn't