ARP rod bolts replacing stock bolts without resizing of the rod
#1
ARP rod bolts replacing stock bolts without resizing of the rod
Can stock rodbolts be replaced with with ARP bolts without having to resize the rods? I've known people to do this and supposedly because of the design of the rod you can get away with it. Most of the time I was the one that had to do it for them, and I'de like to do it to mine if I can. Any help would be appreciated.
#3
Originally Posted by calongo_SS
Use Katech rod bolts if you're worried about it. No resizing required.
You beat me to it
..plus 260ksi tensile strength
Last edited by Katech_Jason; 12-19-2005 at 01:23 PM.
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Homer_Simpson (12-05-2021)
#5
you dont have to resize, the Rod Cap is cracked.
https://ls1tech.com/forums/showthrea...2&page=1&pp=20
https://ls1tech.com/forums/showthrea...2&page=1&pp=20
#6
You need to check clearences and balance with arp's. Katech's are straight replacement. They cost more, but you will save in the long run. Plus be able to sleep at night knowing the things aren't going to fail.
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#8
I havnt installed them, so dont rely on my contribution... But consider this, the bearing clearance on these rods are typically .0025 - .0030, right? Three thousandths is a pretty big clearance with some room to play around in there. I just cant see a similar sized and shaped fastener deforming the rod appreciably as long as its torqued comparibly to stock. Like it was mentioned in that link, resizing may be recommended when instaling the bigger / heavier PRO SERIES bolts, but I just cant see the regular ARPs making much of a difference. Hell the runout on the milling machine could earily be more than the rod is deformed.
#10
Originally Posted by FDLS1
Just got off the phone with ARP tech support, and they say that you should check the roundness of any Rod when changing the fasteners.
#11
Well if what ARP tech said is true, then it goes for the Katech Bolts as well. I decided I am going to go for it, I will bring my Micrometer and Vernier Calipers home from work and change the Rod bolts. I am sure nothing will go wrong especially because the rod is still on the crank so how much out of round could it go replacing 1 bolt at a time.
#13
So what makes you think tightening one bolt or another would be different other then the bolt being a different size? ARP bolts are direct replacement, same size as stock, no modification to fit into the rod, so what makes the Katech so different from the ARP bolts? From what I know there are very few high quality fastener companies in the world and Katech is not one of them, so where do you think they get their bolts from?
#14
Originally Posted by FDLS1
So what makes you think tightening one bolt or another would be different other then the bolt being a different size? ARP bolts are direct replacement, same size as stock, no modification to fit into the rod, so what makes the Katech so different from the ARP bolts? From what I know there are very few high quality fastener companies in the world and Katech is not one of them, so where do you think they get their bolts from?
Over the last 20 years, A1 technologies has earned the reputation of being one of the premier fastener manufacturers for the United States racing industry.
A1 technologies put its expertise to work for the racing industry in the early 80s, developing close relationships with the industry’s finest engine builders, connecting rod and engine block manufacturers.
Today, we are the fastener manufacturer of choice for many top teams and manufacturers in CART, IRL, NASCAR, NHRA, IHRA, IHBA, as well as many others for their critical fastener needs.
A1 technologies put its expertise to work for the racing industry in the early 80s, developing close relationships with the industry’s finest engine builders, connecting rod and engine block manufacturers.
Today, we are the fastener manufacturer of choice for many top teams and manufacturers in CART, IRL, NASCAR, NHRA, IHRA, IHBA, as well as many others for their critical fastener needs.
#16
I'm with FDLS1. I think ARP's comment is either a cop-out or was from someone who doesn't appreciate the difference between a machined "nut & bolt" rod and a cracked, "bolt only" one. It's one thing to drive out knurled press-fit factory bolts and pound in wave ground replacements in a two-piece, machined joint rod and quite another to unthread a bolt and thread in another in a cracked rod with alignment dowels. Would they recommend checking the concentricity when replacing the stock bolts with new stock bolts? How about when re & re -ing the same stock bolts in different rods in the same engine? How about the same bolts in the same holes? If not, what's so different about ARP's vs. stock or Katech? If it's a universal recommendation, how could you ever assemble the engine? After you unscrewed the bolts following "...check(ing) the roundness of any Rod when changing the fasteners." , you would have no way of checking again after fitting the bearings.
Guess we need someone to do a little experiment here...
Re balance, Quote < " You need to check clearences and balance with arp's"> End quote, the weight difference can't be more than 2 or 3 grams per and will be exactly the same for each rod. Considering there is lively disagreement over whether, depending on RPM range, V-8s should be balanced to 50, 51 or 52%, I think it would be tough to make the case that the resultant 50.2% or whatever balance factor was a show-stopper.
Guess we need someone to do a little experiment here...
Re balance, Quote < " You need to check clearences and balance with arp's"> End quote, the weight difference can't be more than 2 or 3 grams per and will be exactly the same for each rod. Considering there is lively disagreement over whether, depending on RPM range, V-8s should be balanced to 50, 51 or 52%, I think it would be tough to make the case that the resultant 50.2% or whatever balance factor was a show-stopper.
#17
No response from Katech? What is the difference between removing stock and putting a different bolt in? If you ask me Katech requires:
KATECH ROD BOLT TORQUE SPECIFICATIONS:
• Remove old bolts from connecting rod
• Apply motor oil to the threads of the Katech rod bolts
• Thread bolts into connecting rod and torque to 50 ft/lbs
And ARP 40ft/lbs so which one would make the Rod out of Round?
KATECH ROD BOLT TORQUE SPECIFICATIONS:
• Remove old bolts from connecting rod
• Apply motor oil to the threads of the Katech rod bolts
• Thread bolts into connecting rod and torque to 50 ft/lbs
And ARP 40ft/lbs so which one would make the Rod out of Round?
#19
Originally Posted by FDLS1
No response from Katech? What is the difference between removing stock and putting a different bolt in? If you ask me Katech requires:
KATECH ROD BOLT TORQUE SPECIFICATIONS:
• Remove old bolts from connecting rod
• Apply motor oil to the threads of the Katech rod bolts
• Thread bolts into connecting rod and torque to 50 ft/lbs
And ARP 40ft/lbs so which one would make the Rod out of Round?
KATECH ROD BOLT TORQUE SPECIFICATIONS:
• Remove old bolts from connecting rod
• Apply motor oil to the threads of the Katech rod bolts
• Thread bolts into connecting rod and torque to 50 ft/lbs
And ARP 40ft/lbs so which one would make the Rod out of Round?