ARP rod bolt ?
 

With new ARP 2000 rod bolts, and using a stretch gauge how for do you guys stretch them. The bolts I have are 7/16 X 1.55 long.

Thanks in advance.

Fixx
 

over torque by 10 ft lbs or stretch them .006,,

Warren,
You cannot listen to any replies on this. What you need to do is:

Call the connecting rod manufacturer and ask them the question. There are many different ARP2000 bolts and many different stretch and torue specs for them. Different rod manufacturers use the same exact bolt, yet specify a different torque and stretch figure. ONLY the rod manufacturer can answer this question.

If you try to call ARP and ask them, they will dodge the question for as long as you feel like keeping them on the phone, but they will not commit to a stretch or torque spec. They will also tell you that you need to ask the rod manufacturer :( Believe me I am speaking from experience.

If the bolts are replacements for the stock bolts, you can look them up in the ARP catalog, but I dont think they make a stock replacement bolt in the ARP2000 material, so I am pretty sure yours must be a cap screw bolt.

Call the rod manufacturer !!!!

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Thanks Bill, I will.

Warren,
That is good advice from Bill, what rods are they?
I had the same questions a while back and talked to Oliver and was told how the process is done for the Oliver rod with WSB bolts.. They use the torque angle method, which is tighten to low setting of torque (in this case 35 lb/ft) and then twist them an additional 42 degrees. That should give a stretch of .0053"-.0057". The lube that Oliver supplies is liberally applied and the rotation is to be a quick motion, to avoid the twisting of the fastener, adding to the mix. Using the angle guage, allowed me to get the quick motion and consistent stretches. If the bolt is too short, completely loosen it and relube and try again. Same if its too long.. But if you go over about .007" the bolt is ruined.
Now as Bill said. This only applied to my rods and bolts. But the techique can be used with other fasteners, if the manufacture can give you the amount of stretch that they require for the clamp load. Ask them for the stretch and recommended lube. They should be able to give you a technique to get to the proper clamping force for that product.

Hope that helps.. I know it answered a lot of questions for me when it came to buttoning up the rods..
Another trick he told me about was the stretch gauge. It has sharp points on it. The dimple in my rod bolts had a "not so pointed" bottom. So the point on the guage could slide around and give you a false reading (your looking at tenths here). So he suggested I dull the end of the point so it seats on the egdes of the dimple not the bottom of it. It will give more accurate results. And you will notice the bolts may be the same length, but the dimples may not give you the same length between bolts. You compensate for each bolt as you tighten it..

Hope that helps.
Dick

They are Oliver rods, the only reason for changing the bolts is because they have been in the motor for 3 years, and have been torqued at least 5 times. Kinda thought is was time.

Talk to Tim at Oliver, he is very knowledgeable. I have torqued my new rod bolts a couple dozen times. Tim said that I can't do near the stress (unless they are over stretched) on torquing a rod bolt, that it sees in a motor when it turns the corner to go down with the crank pulling it, with no combustion force.

Thats good to know, thanks.