Quick Question about ARP rod bolts
06-20-2008, 12:10 AM
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Quick Question about ARP rod bolts Hey
I have these ARP rod bolts. I know how to install them I just want to know what the final torque specs. I read the tutorial and I know you torque them down 2 times to 30 ft/lbs and then I know with the katech rod bolts you have a final torque spec of 50 ft/lbs.
So what are the final torque specs for ARP. A buddy of mine recomended 60 ft/lbs for ARP.
Thanks
Tilly
I have these ARP rod bolts. I know how to install them I just want to know what the final torque specs. I read the tutorial and I know you torque them down 2 times to 30 ft/lbs and then I know with the katech rod bolts you have a final torque spec of 50 ft/lbs.
So what are the final torque specs for ARP. A buddy of mine recomended 60 ft/lbs for ARP.
Thanks
Tilly
06-20-2008, 03:10 AM
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What is the part number of the bolt?
ARP has many different types and grades of bolt for a given application, the torque and stretch will differ between the material, length, and beam design of the specific bolt.
ARP has many different types and grades of bolt for a given application, the torque and stretch will differ between the material, length, and beam design of the specific bolt.
06-20-2008, 10:22 AM
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Okay, now I just found the directions for these ARP bolts and it says 3 time to 40 ft/lbs and they say use their assembly lube which i do not have. Is there any substitute for there lube that is over the shelf.
Now as read more into installing these bolts. What do they mean that the Rods should be resized before I install new bolts?
Now as read more into installing these bolts. What do they mean that the Rods should be resized before I install new bolts?
Last edited by tilly; 06-20-2008 at 02:00 PM.
06-20-2008, 03:16 PM
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If the rods are stock type which utilize a rod bolt which is a pressed in design the removal and re-installation of the pressed in bolts can deform the big end of the rod causing the bearing bore too be out of round and off size.
If I am not mistaken this part number rod bolt is of the cap screw design and is not a pressed in bolt, however anytime you are reusing stock or even using brand new rods the big end bore of the rod needs too be checked for size, roundness, and cocentricity and quite often they will need to be faced and honed. I have to resize brand new rods right out of the box all the time, even from some of the "big name" companies.
Failure to ensure the rod's big end is round and on size could cause you too have improper crush even if the bearing too journal clearance is correct.
The spec for that bolt according too my book is .0064" stretch at 40lbft of torque using ARP's moly lube.
Do not rely on this torque method without using ARP's assembly lube, you will just be guessing. The lube affects the friction drastically, which in turn affects the stretch which is what the whole thing depends on.
If I am not mistaken this part number rod bolt is of the cap screw design and is not a pressed in bolt, however anytime you are reusing stock or even using brand new rods the big end bore of the rod needs too be checked for size, roundness, and cocentricity and quite often they will need to be faced and honed. I have to resize brand new rods right out of the box all the time, even from some of the "big name" companies.
Failure to ensure the rod's big end is round and on size could cause you too have improper crush even if the bearing too journal clearance is correct.
The spec for that bolt according too my book is .0064" stretch at 40lbft of torque using ARP's moly lube.
Do not rely on this torque method without using ARP's assembly lube, you will just be guessing. The lube affects the friction drastically, which in turn affects the stretch which is what the whole thing depends on.
06-20-2008, 07:39 PM
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I am just replacing the rod bolts on my stock bottom end. I am not taking it completely apart. So, would I be fine just replacing the bolts. using the proper lube and doing 1 bolt at a time?
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06-20-2008, 09:10 PM
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ratfink is correct, rod bolt stretch is really the only definitive method of determining the correct tq. However, just going by ARPs recommendations is pretty close. Just make sure you brandish them correctly with ARP lube. The bolts should have a piece of paper in them with the tq specs with assy. lube OR with motor oil. They're different, follow the directions. I put mine in about 7K ago and have spun my motor past 7K RPMs many times. You're on the right track, an ouce of prevention is worth a pound of cure.
06-20-2008, 10:26 PM
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I have the ARP Pro Series bolts in my car. I used the ARP lube that came with my bolts and torqued to 40 and loosened twice, then a final pass at 40. Working fine.
06-20-2008, 10:35 PM
#10
If the rods are stock type which utilize a rod bolt which is a pressed in design the removal and re-installation of the pressed in bolts can deform the big end of the rod causing the bearing bore too be out of round and off size.
If I am not mistaken this part number rod bolt is of the cap screw design and is not a pressed in bolt, however anytime you are reusing stock or even using brand new rods the big end bore of the rod needs too be checked for size, roundness, and cocentricity and quite often they will need to be faced and honed. I have to resize brand new rods right out of the box all the time, even from some of the "big name" companies.
Failure to ensure the rod's big end is round and on size could cause you too have improper crush even if the bearing too journal clearance is correct.
The spec for that bolt according too my book is .0064" stretch at 40lbft of torque using ARP's moly lube.
Do not rely on this torque method without using ARP's assembly lube, you will just be guessing. The lube affects the friction drastically, which in turn affects the stretch which is what the whole thing depends on.
If I am not mistaken this part number rod bolt is of the cap screw design and is not a pressed in bolt, however anytime you are reusing stock or even using brand new rods the big end bore of the rod needs too be checked for size, roundness, and cocentricity and quite often they will need to be faced and honed. I have to resize brand new rods right out of the box all the time, even from some of the "big name" companies.
Failure to ensure the rod's big end is round and on size could cause you too have improper crush even if the bearing too journal clearance is correct.
The spec for that bolt according too my book is .0064" stretch at 40lbft of torque using ARP's moly lube.
Do not rely on this torque method without using ARP's assembly lube, you will just be guessing. The lube affects the friction drastically, which in turn affects the stretch which is what the whole thing depends on.
listen to above advice, it is spot on. I have heard this multiple times from highly experience engine builders/tuners.
yeah you may be ok, but you will know that you aren't when you have a rod hanging out the side of the block. To me its not worth it.
