Definitive answer on ARP rod bolts on gen3 rods
02-21-2019, 12:49 PM
#1
Definitive answer on ARP rod bolts on gen3 rods
I hinted before about how i had 2 sets of fresh rods at the machine shop to have them modified for floating pins. They also trued up the big end and surfaced it. After that i took them back to check how the rod bolts sized up in them. They installed both the 134-6006 8740 and the 234-6301 PRO2000
The 8740 need 40lbs the PRO2000 take 45lbs per ARP.
They both distorted the rod end over .001. So in reality using .002 over rod bearings when installing ARP rod bolts and having them honed is the proper way to do it.
I will be trying it the cheap way also and checking with a std bearing before i have all of them resized to visually show the difference vs me just telling you. I dont have a dial bore gauge so ill be using plastigauge. Some of you may groan and say get the right tools, but i have quite a few projects going on and would rather leave the rest of the work up to the machine shop. I did have them touch up one rod so ill use the plastigauge on both....and on both sides of the bearing.
Thoughts? Comments?
The 8740 need 40lbs the PRO2000 take 45lbs per ARP.
They both distorted the rod end over .001. So in reality using .002 over rod bearings when installing ARP rod bolts and having them honed is the proper way to do it.
I will be trying it the cheap way also and checking with a std bearing before i have all of them resized to visually show the difference vs me just telling you. I dont have a dial bore gauge so ill be using plastigauge. Some of you may groan and say get the right tools, but i have quite a few projects going on and would rather leave the rest of the work up to the machine shop. I did have them touch up one rod so ill use the plastigauge on both....and on both sides of the bearing.
Thoughts? Comments?
02-21-2019, 12:58 PM
#2
this isn't common knowledge by now? for what it's worth, i've spun a few stock bottoms to 7,500+ from 99 model ls1 to newer lq4 and lq9. Never had a rod bolt let loose. I did kick a few rods, but the bolts held strong. I only recommend aftermarket rod bolts when doing a fresh build with all machine work.
02-21-2019, 01:19 PM
#3
No, its not. That is why i did the test.
Every single post turns into just what you said.
"Well i did it this way and it lasted."
But did you actually go back and check the rod bolt stretch? Thats the only way to know there. I can tell you around 8k the stock rod bolts (not including the LSA or LS7) will stretch.
Every single post turns into just what you said.
"Well i did it this way and it lasted."
But did you actually go back and check the rod bolt stretch? Thats the only way to know there. I can tell you around 8k the stock rod bolts (not including the LSA or LS7) will stretch.
02-21-2019, 01:52 PM
#4
Its common to those who know and listen.
I had it tested a few years back as well and had similar results.
Also tested the Infamous Katech Bolts with minimal to no distortion.
But the people that like to regurgitate on Tech Spit out the same garbage. "I Swapped ARP bolts in my drive way and did it 1 at a time blah blah blah. Spin it to 7500 and no issues."
Then there are those that did the swap and spun bearings shortly after...
Even Gm does not recommend you spin the stock rods past 6600 RPM.
Every stock short block I have ever seen spit a rod out, the big end was still attached to the crank and the bolts where still tight.
At this point I don't even recommend ARP Rod bolts on the stock rods any more. If you want to spend the money on them and the reconditioning why not spend a little more and get better rods?
For they Nay Sayers about the Factory Rod bolts. Look at Sloppy mechanics.
I did the Same Exact thing on my junk yard Twin Turbo 6.0L Motor. Replaced the 2 damaged rods and pistons with 2 used Rods and Pistons. Reused Same rings, Same bearings that came out of those holes.
I had it tested a few years back as well and had similar results.
Also tested the Infamous Katech Bolts with minimal to no distortion.
But the people that like to regurgitate on Tech Spit out the same garbage. "I Swapped ARP bolts in my drive way and did it 1 at a time blah blah blah. Spin it to 7500 and no issues."
Then there are those that did the swap and spun bearings shortly after...
Even Gm does not recommend you spin the stock rods past 6600 RPM.
Every stock short block I have ever seen spit a rod out, the big end was still attached to the crank and the bolts where still tight.
At this point I don't even recommend ARP Rod bolts on the stock rods any more. If you want to spend the money on them and the reconditioning why not spend a little more and get better rods?
For they Nay Sayers about the Factory Rod bolts. Look at Sloppy mechanics.
I did the Same Exact thing on my junk yard Twin Turbo 6.0L Motor. Replaced the 2 damaged rods and pistons with 2 used Rods and Pistons. Reused Same rings, Same bearings that came out of those holes.
02-21-2019, 04:43 PM
#5
Its common to those who know and listen.
I had it tested a few years back as well and had similar results.
Also tested the Infamous Katech Bolts with minimal to no distortion.
But the people that like to regurgitate on Tech Spit out the same garbage. "I Swapped ARP bolts in my drive way and did it 1 at a time blah blah blah. Spin it to 7500 and no issues."
Then there are those that did the swap and spun bearings shortly after...
Even Gm does not recommend you spin the stock rods past 6600 RPM.
Every stock short block I have ever seen spit a rod out, the big end was still attached to the crank and the bolts where still tight.
At this point I don't even recommend ARP Rod bolts on the stock rods any more. If you want to spend the money on them and the reconditioning why not spend a little more and get better rods?
For they Nay Sayers about the Factory Rod bolts. Look at Sloppy mechanics.
I did the Same Exact thing on my junk yard Twin Turbo 6.0L Motor. Replaced the 2 damaged rods and pistons with 2 used Rods and Pistons. Reused Same rings, Same bearings that came out of those holes.
I had it tested a few years back as well and had similar results.
Also tested the Infamous Katech Bolts with minimal to no distortion.
But the people that like to regurgitate on Tech Spit out the same garbage. "I Swapped ARP bolts in my drive way and did it 1 at a time blah blah blah. Spin it to 7500 and no issues."
Then there are those that did the swap and spun bearings shortly after...
Even Gm does not recommend you spin the stock rods past 6600 RPM.
Every stock short block I have ever seen spit a rod out, the big end was still attached to the crank and the bolts where still tight.
At this point I don't even recommend ARP Rod bolts on the stock rods any more. If you want to spend the money on them and the reconditioning why not spend a little more and get better rods?
For they Nay Sayers about the Factory Rod bolts. Look at Sloppy mechanics.
I did the Same Exact thing on my junk yard Twin Turbo 6.0L Motor. Replaced the 2 damaged rods and pistons with 2 used Rods and Pistons. Reused Same rings, Same bearings that came out of those holes.
leave stock rods and bolts alone or swap them both.
02-21-2019, 07:08 PM
#6
Back in 2013/14 when I was first putting a P1 on my Tahoe, it was all the rage to put ARP rod bolts in. Basically everyone told me to do it. That gen3 rods could take 500, but with bolts could take 700.
Well I looked for days, (and I consider myself a pretty good internet searcher) and when I finally found rod bolts for a gen3 5.3, they were like $250. I didn't have that kinda money for 16 bolts at the time, so I skipped em
still haven't lost a rod in that motor, and it's been I think 26000 miles
not saying they aren't an upgrade, but the cost vs benefit isn't there for me. Plus the idea/notion of conditioning the big end and a new set of bearings was something never mentioned to me. So I very well may have spent the $250, and time to slap those bolts in: and ruined my bottom end (based on what these guys and your numbers are saying)
Well I looked for days, (and I consider myself a pretty good internet searcher) and when I finally found rod bolts for a gen3 5.3, they were like $250. I didn't have that kinda money for 16 bolts at the time, so I skipped em
still haven't lost a rod in that motor, and it's been I think 26000 miles
not saying they aren't an upgrade, but the cost vs benefit isn't there for me. Plus the idea/notion of conditioning the big end and a new set of bearings was something never mentioned to me. So I very well may have spent the $250, and time to slap those bolts in: and ruined my bottom end (based on what these guys and your numbers are saying)
02-22-2019, 12:40 AM
#7
It was more of a “to do” mod back in 99-02 because the 98 ls1 had a rod bolt issue that gm corrected. After a few years we saw the trend of low mile arp bottom ends eating themselves while others put stock rod bolt engines through the ringer with no issues. That was back when the ls platform was new and fun. New records every weekend, new parts daily, and the entire. World didnt have F/I.
Back then, a low 13 second 4.8 was setting the world on fire. Things have progressed since then lol.
Back then, a low 13 second 4.8 was setting the world on fire. Things have progressed since then lol.
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02-22-2019, 01:32 AM
#8
Scat JUST released their 6.100 floating pin i beam rods so that is a game changer of course.
But they are $350
I spent $140 for bolts and machine work so its quite a bit of difference.
At that point ill likely change all the rods i have over to 8740s and sell the stock rod bolts if anyone wants them. Its not alot extra for me and good insurance for later if i build an engine with them.
I used the PRO2000 on the 4.8 rods for the 333 because i expect it to be beat on and at 7500 to 7800.
The rod bolts on TSPs sbe ls3 were not happy at 8k+. I know thats not realistic but a good measuring stick. If it takes better rod bolts to keep it happy then its not that bad. Its always better to run a fresh surface anyway.
And trying to say sloppy did something so its a good idea isnt a frame of mind i follow. They have passed around some misinformation and havent been called out yet on them.
But they are $350
I spent $140 for bolts and machine work so its quite a bit of difference.
At that point ill likely change all the rods i have over to 8740s and sell the stock rod bolts if anyone wants them. Its not alot extra for me and good insurance for later if i build an engine with them.
I used the PRO2000 on the 4.8 rods for the 333 because i expect it to be beat on and at 7500 to 7800.
The rod bolts on TSPs sbe ls3 were not happy at 8k+. I know thats not realistic but a good measuring stick. If it takes better rod bolts to keep it happy then its not that bad. Its always better to run a fresh surface anyway.
And trying to say sloppy did something so its a good idea isnt a frame of mind i follow. They have passed around some misinformation and havent been called out yet on them.
02-22-2019, 06:23 AM
#9
My point is, the Factory Rods bend before the Rod bolts become an issue on a 1000HP turbo set up.
It's not the same as spinning to 8K, But the rods where not designed for either situation. I can only imagine what powdered metal rods do under those type of forces.
I will agree he does put miss information out there. I also don't agree with some of his practices either.
It's not the same as spinning to 8K, But the rods where not designed for either situation. I can only imagine what powdered metal rods do under those type of forces.
I will agree he does put miss information out there. I also don't agree with some of his practices either.
02-22-2019, 10:40 AM
#10
I have a couple questions
A) where is the GM literature about the 6700 limit?
B) where did you find bolts and machine work for $140? Are you also going to rebalance after having the big end conditioned?
C) are 4.8 rods considered stronger for ultimate RPM simply because of the mechanics? I never hear 4.8 guys worrying about rod speed, but I might not be listening hard enough
A) where is the GM literature about the 6700 limit?
B) where did you find bolts and machine work for $140? Are you also going to rebalance after having the big end conditioned?
C) are 4.8 rods considered stronger for ultimate RPM simply because of the mechanics? I never hear 4.8 guys worrying about rod speed, but I might not be listening hard enough