okay, so today i dropped my rods off at the machine shop along with my block. upon seeing my rods with the arp rod bolts, the machinist tells me that i would need to have my rod journals(?) shaved. he said it was because the arp bolts are different from the stock bolts and it would cause the metal to distort. so he would have to shave a little material off the end caps and some off the rod(the flat parts) and then reshape the journal area to make it round again.

has anyone ever heard of this before when putting their arp rod bolts on? anyone ever just put the bolts on without any problems?

any suggestions or advice welcome....

 

it can happen. I would strongly recommend doing so. at the same time your
machinist can take your crank and rod bearings and make the clearances correct
so you dont have to worry about proper bearing size.

 

stephan, have you had experience with that? i really gotta know because i'm running out of money and time to build my motor. i would do it, but the guy's gonna charge me $80 for 4 rods.

anybody else....?

 

what you can do is take measurements with the stock bolts torqued to spec
and then take them again with the arp bolts and see if they distorted at all.

 

that's what i was planning to do before i had him start on it. like i said before, i don't doubt that it could happen, i just wanted to see if anyone had experienced this kind of situation before and what they did about it. plus, it did seem pretty pricey for what he was going to do. thanks for the heads up though!!

 

just the other side of the coin...

i just did my own rod bolts on my B20 and was reliably informed that i had nothing to worry about regarding the journals.

i trust this advice and it makes sense since the torque specs of the bolts is about the same as the stock torque specs...

any comments???

t..

 

Ummm, torque specs on ARP LS rod bolts? You mean STRETCH specs?

 

i'm feeling more confident....

keep those replies coming.

 

Right, you have to torque the ARP bolts down 3 times @ 26 ft/lbs as per their instrucions to get the right stretch specs.

EI - torque, loosen, re-torque, loosen, re-torque again

 

I would think if you would torque the arp rod bolt to the same spec as stock, there would be no distortion to the rod. You would have the advantage of a stronger rod bolt. SgT or anyone elose, am I wrong with this logic? If you are going to resize the big ends because of the rod bolts, you should probably just go with Eagles.

 

that's what i was just thinking. between shotpeening, getting arp rod bolts, and machining, i think i could have just gotten aftermarket rods for just a little bit more, no? (one of the reasons i don't want to pay for the machining.)

 

the bolts are press fit, which can distort the rod in the area surrounding the holes
since they are a little bit bigger than the stock bolts.
it has nothing to do with torque spec.

 

When I had my motor rebuilt, the shop resized the rods when installing the APR bolts.

 

I see...the only thing I do with stock rods is throw them in the trash

 

ARP recommends that you have the rods resized...

http://www.arp-bolts.com/pages/produ...ks/how_to.html

t..

 

i asked my machine shop about this very same question. they told me that they recommend MESURING the big end bore after the new rod bolts are pressed in and torqued to spec. if they are out of round then they would re-bore the big end. if they are ok then they would leave them alone.

when i had ARP rod bolts pressed into LS rods the big ends were perfectly fine. so no re-boring was necessary............and that engine was running fine up to 8000rpm