SBC ARP Main Bolt Torque Question
08-07-2008, 03:27 PM
#1
Burning Brakes
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SBC ARP Main Bolt Torque Question
Just getting ready to bolt the bottom end together on a 385 small block chevy motor I'm building for another car.
A buddy of mine had a set of ARP main bolts (PN #134-5202) that he had purchased a few years back, never used, and gave them to me. From what I can tell it looks like when using the ARP main bolts with their ARP moly lube that comes with them they want you to torque all of the main bolts to 65 ft/lbs. (both the inner and outer main cap bolts on a 4 bolt main motor)
Is this correct? I know when using the factory main bolts the spec was always inners 70 ft/lbs and outers 65 ft/lbs. Also it sounds like they want you to torque them all to 45 ft/lbs then to the 65 ft/lbs, loosen them back up, and then repeat this procedure 3 times to properly strectch the new main bolts. I do not have a issue doing this I just have never done this before but these are the first ARP main bolts I have ever used. What do you guys do?
A buddy of mine had a set of ARP main bolts (PN #134-5202) that he had purchased a few years back, never used, and gave them to me. From what I can tell it looks like when using the ARP main bolts with their ARP moly lube that comes with them they want you to torque all of the main bolts to 65 ft/lbs. (both the inner and outer main cap bolts on a 4 bolt main motor)
Is this correct? I know when using the factory main bolts the spec was always inners 70 ft/lbs and outers 65 ft/lbs. Also it sounds like they want you to torque them all to 45 ft/lbs then to the 65 ft/lbs, loosen them back up, and then repeat this procedure 3 times to properly strectch the new main bolts. I do not have a issue doing this I just have never done this before but these are the first ARP main bolts I have ever used. What do you guys do?
08-07-2008, 03:39 PM
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Team Owner
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It's probably good to follow the manufacturer's suggestions. However, I have never backed them out and repeated twice to stretch them. I used a 3 step process to get to the 65. I torque to 21 on all bolts. Then, 42, and finally 65. You'll notice using ARP and the lube that you get to that torque reading smoother and it feels different from using standard grade 8 bolts.
08-07-2008, 04:10 PM
#3
Race Director
The backing off thing is common these days for aluminum heads even with oem bolts. Check factory service manuals.
Use ARP torque specs, they give different readings depending on the lube you use. It's on their website.
Use ARP torque specs, they give different readings depending on the lube you use. It's on their website.
08-08-2008, 08:33 AM
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Burning Brakes
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Sounds good. I did a little poking around on their website and found this: "Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP lubricants are used, five cycles are required before final torquing."
08-08-2008, 04:08 PM
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Burning Brakes
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I noticed that too. Well that leaves me in a intersting situation since the block has already been bored, decked, line honed, and clearanced. Hum.... 
08-08-2008, 09:29 PM
#7
Race Director
I had my 400ci block line honed with new ARP main studs. One shop said I would be OK but another said I should do it, so I did it.
Interesting paragraph on torquing the ARP bolts/studs, glad my bottom end isn't buttoned up yet
Interesting paragraph on torquing the ARP bolts/studs, glad my bottom end isn't buttoned up yet
