Sorry 4 this question in advance since if I didnt lose the paper I wouldnt be asking right now. Got some summit stage 1 connecting rods with arp bolts and the arp assembly lube, wanted to know what the torque specs were for the bolts with the assembly lube. Thx in advance guys.

 

http://www.arp-bolts.com/pages/tech/images/fasttorq.pdf

 

What size are the rod bolts

 

Uh i thought you knew the size

http://www.arp-bolts.com/pages/tech/images/rod_bolt.pdf

Using that chart, then crossreferencing the part numbers to engine size application, 50 ft-lbs is the number they say.

 

every arp rod bolt i evve used the instructions said to torque them and back them off twice before the finial torque or use a rod bolt gauge.

 

ede, I am glad u are on this site. I have read more important tips from u than in both of my manuals. I mean it. I would never have know to do the double torque on the rod bolts. I would have torqued them down double checked them and on to the next. I get over welmed when I think all of the things I have to remember.Thanks

 

well thanks but not sure all the praise is that well deserved. all the info i got came with the rod bolts or from arp web site. i'd believe them long before i would soem dumbass like me on the net. the torque two time thing is to prestreach the new rod bolts, doesn't really apply to stock bolts from gm.

 

Thx, Summit says 60ft lbs with the lube so there ya go. Thanks guys and sorry again for the stupid thread.

 

Found my paper, you are correct my fault 50lbs is correct, stupid summit racing. Thanks again, luckily didnt start the engine yet w00t :hail:

 

ok but if you go to the arp website they give this elaborate explanation of using a stretch guage to torque your rod bolts and then when youve done that they say to "resize" them. what the hell are they talking about and cant you use a micrometer to do the same thing? i don't see why you just cant use the arp bolts, prestretch them like ede said and then torque them to spec. any comments?

 

A strain guage is definitely the most accurate way of torqueing rod bolts. The idea behind any fastener is that as you 'tighten' it you're causing a normal stress within the bolt (and thus a force acting to hold the two parts together). Knowing the properties of the bolt material (ie modulus of elasticity) and it's cross sectional area, you can acheive this acting force by causing a strain in the bolt ( change in length divided by original length ). I could throw the formulas at you if you wish but basically ARP can determine the amount that the bolt needs to be stretched in order to achieve the necessary force to hold the rod cap on. Some people do not have access to a strain gauge however, thus most repair manuals and assembly instructions will give recommended rod bolt torque values. This is their approximation as to how much torque is generally required to achieve the necessary amount of bolt elongation. I would not trust this method for rod bolts however, as i've seen significant deviation from this approximation. Either go buy a strain guage or pay someone else to do it.


Patrick DeGrosse Jr.

 

good explanation but what do they mean by resizing them

 

Basically, when you put in new bolts, the cap may seat differently than it did before. Due to the nature of the rod, it obviously needs to be perfectly round. Even the slightest thousandth of an offset can be bad. I believe resizing a rod means to make the big circle round again.

 

to resize a rod a small amount is removed from the syrface of the cap, making the hole out of round. the hole is them honed back to round and to spec. last set i had resized cost 80 dollars including pressing the pistons on.

 

Def not a stupid thread.no question is a stupid question. .arp website is acting crazy right now and I need the torque specs for the rod bolts..thanx to u starting this thread I now have my answer. .