Question about rod bolt swap
08-23-2004, 12:35 PM
#1
6600 rpm clutch dump of death Administrator
Thread Starter
Question about rod bolt swap Has anyone outside of the car checked to see if the rods go out of round when installing ARP bolts?
I'm not asking if you've swapped them in car, etc... I'm asking if anyone has ever checked the before and after dimensions of the rods when installing bolts...
I know the rods are PM/Cracked Rods, but I see folks changing bolts, and I can't see any rod not deforming when you put a stronger fastener with more clamping force on it... I'm just wondering if anyone has checked to see how much.
I'm not asking if you've swapped them in car, etc... I'm asking if anyone has ever checked the before and after dimensions of the rods when installing bolts...
I know the rods are PM/Cracked Rods, but I see folks changing bolts, and I can't see any rod not deforming when you put a stronger fastener with more clamping force on it... I'm just wondering if anyone has checked to see how much.
08-23-2004, 02:16 PM
#2
I can shift faster than you.
iTrader: (21)
Join Date: Nov 2001
Location: Baton Rouge, LA
Posts: 5,133
Likes: 0
Received 0 Likes
on
0 Posts
Jarrod, I have checked the housing bore on the rods before and after the rod bolt install (ARP Pro-series bolts). There is some definite deformation after the new bolts are installed. Every motor we build with stock rods has the housing bore re-sized .002" larger than stock to accept a new, oversized bearing from Clevite for this very reason.
I can't remember off the top of my head exactly how much out-of-round the rods went after the new bolts, but I do have it all info written down. I can get this once I'm done with school today.
Jason
I can't remember off the top of my head exactly how much out-of-round the rods went after the new bolts, but I do have it all info written down. I can get this once I'm done with school today.
Jason
08-23-2004, 05:51 PM
#4
TECH Enthusiast
Join Date: Feb 2004
Location: Foley, Alabama-southern Alabama
Posts: 743
Likes: 0
Received 0 Likes
on
0 Posts
J-rod, just because a rod bolt is stronger does"nt mean it has more clamping force at the same torque setting or the same stretch,although it will take more abuse and have more tensile strenth. 
08-23-2004, 08:11 PM
#5
6600 rpm clutch dump of death Administrator
Thread Starter
Agreed, but to get the proper use out of the bolt you will end up torquing it more to "stretch" it. From what I have read, most bolt swaps involve folks putting bolts to a higher torque value than stock.
08-23-2004, 08:20 PM
#7
King of Pigskin Knowledge
iTrader: (7)
Join Date: Dec 2002
Location: Ohio
Posts: 602
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by J-Rod
Agreed, but to get the proper use out of the bolt you will end up torquing it more to "stretch" it. From what I have read, most bolt swaps involve folks putting bolts to a higher torque value than stock.
Trending Topics
08-24-2004, 08:27 AM
#8
TECH Enthusiast
Join Date: Feb 2004
Location: Foley, Alabama-southern Alabama
Posts: 743
Likes: 0
Received 0 Likes
on
0 Posts
Thats what I meant, if you tighten a fastener that is the same diameter and thread pitch the same torque then the clamping force is the same even though the fastener is much stronger and will not s-t-r-e-t-c-h like the stock bolt at high loads, such as high rpm.What J-rod was asking was if you change rod bolts would it make the connecting rod get ob-long or out of perfect round because of the better bolts and it can happen! 
