Thread: ARP rod bolts

Tweet

ARP#134-6006 would .001-.008 difference in relaxed length in a set of 16 be normal ? I can't get ARP to answer an e-mail .

Originally Posted by suprstock

ARP#134-2006 would .001-.008 difference in relaxed length in a set of 16 be normal ? I can't get ARP to answer an e-mail .

I've called them several times and gotten an answer immediately. Also - their prices can be much cheaper that way as well especially if you just need some odds and ends

What are you measuring them with? I had the same ? when I built the latest engine. I used the cap screw type and their relaxed were spread out as well.
I was told to 1) measure relaxed anyway, note reading 2) stretch to .0063
3) take em off and measure again with the same dial, note reading. If it has increased by more than .001", round file. IMO- these bolts out of the box will vary in their length, that is why ARP has you measure and write down their length so you can compare if you ever do a tear down/rebuild.

That's what I think , I doubt they can produce them the exact same length, they are cap screws measuring with stretch gauge .had to put 68 lbs on the longest one to get .005 stretch .

68lb sounds about right for .005". If you reference the directions that came with the bolts, ARP says that .0063 stretch with moly lube should fall somewhere around the 75 lb area.

if 8740 cap screws they fall around 60to 65 lbs with ARP moly lube or a 3/8 thru bolt then 50 if a 8740 with ARP moly . if you TQ wrench is not off or lack of lube or another lube other then listed for stretch.in a rod vice i run them up and down on tq 3 times this helps seat the bolts .i use my mic to check stretch at lower Tq and move up till stretch is right . the bolt is not allways listed in ARP book or they may not tell you the TQ at arp i know this first hand .... if scat built the rod or others there name can be on the bolt head then say ARP . like Scat ARP then you have to call scat on TQ ARP will not tell you or help you. if its a ARP 2000 bolt 7/16 then its about 75 lbs with moly.i will add i never lost a rod from from TQ. first i take the rod apart after checking housing bore size if i did not rebuild it .. i tune it in if needed or send it back if way out. then back apart wash it very good getting all junk out of the threads with a round nylon brush and flush them out then blow out them out put moly on threads and under the bolt head slowy run up to tq check .this work for me .i done a set or two