Bulk ARP bolts torque spec
#1
Bulk ARP bolts torque spec
Do you guys use ARP specs or GM?
I'm using the bulk fasteners for the oil pump mounting, cam timing gear, and plate. I plan on using loctite for this application.
ARP's 24 ftlbs or GMs 18 ftlbs?
(Threading into the Aluminum block just scares me lol..)
I'm using the bulk fasteners for the oil pump mounting, cam timing gear, and plate. I plan on using loctite for this application.
ARP's 24 ftlbs or GMs 18 ftlbs?
(Threading into the Aluminum block just scares me lol..)
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#9
That's MISTER MODERATOR
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Perhaps these (ARP) bolts will achieve the ARP spec if turned into an iron block. This is why GM lists the torque for these bolts into an aluminum block at less.
I doubt you'd reach the "correct" fastener stretch on these small bolts threaded into an aluminum block-as also stated by Russ.
On such a small thread at these low tension levels, I don't think using locktite instead of thread lube will make any difference. Not a bad idea to use locktite-you'll sleep better.
Follow GM's numbers.
I doubt you'd reach the "correct" fastener stretch on these small bolts threaded into an aluminum block-as also stated by Russ.
On such a small thread at these low tension levels, I don't think using locktite instead of thread lube will make any difference. Not a bad idea to use locktite-you'll sleep better.
Follow GM's numbers.
#11
Actually just found out that the countersunk cam retainer plate bolts should only go 12ft/lbs. Latest spec from a subscription service the machine shop I use pays for.
#12
TECH Senior Member
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However, you can spend a lot of time chasing these parameters but if you don't have an accurate torque wrench it is all in vain.
#13
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When i ordered and installed my arp bolts, i ordered the ones made for the ls1 engine, so when arp developed the specs, it was for the aluminum engine. Cleaning the holes is the part i always worry about. Clean, chase clean, paper towels to poke in the holes and clean again, so theres no extra resistance when threading in a bolt
#14
The bolt preload is determined by the applied torque, the bolt parameters (size, thread, fit class, etc.) and the friction. Friction is the only parameter you can "attempt" to control and it is usually done with lube. That's why ARP spent so much time developing their new lube. As to the friction differences between their lube and Loctite, only ARP would have that data and I would go straight to them.
However, you can spend a lot of time chasing these parameters but if you don't have an accurate torque wrench it is all in vain.
However, you can spend a lot of time chasing these parameters but if you don't have an accurate torque wrench it is all in vain.
#15
Get this....
ARP gets a BIG thumbs down!!! I tried to get the torque spec from them and they said 24-28ftlbs for the 8mm bolts. I asked them if that tq was safe for an aluminum engine, I get "That is the torque for those bolts"! ARG! I may not even use them now. The won't even give a straight answer.
ARP gets a BIG thumbs down!!! I tried to get the torque spec from them and they said 24-28ftlbs for the 8mm bolts. I asked them if that tq was safe for an aluminum engine, I get "That is the torque for those bolts"! ARG! I may not even use them now. The won't even give a straight answer.
#16
TECH Junkie
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Get this....
ARP gets a BIG thumbs down!!! I tried to get the torque spec from them and they said 24-28ftlbs for the 8mm bolts. I asked them if that tq was safe for an aluminum engine, I get "That is the torque for those bolts"! ARG! I may not even use them now. The won't even give a straight answer.
ARP gets a BIG thumbs down!!! I tried to get the torque spec from them and they said 24-28ftlbs for the 8mm bolts. I asked them if that tq was safe for an aluminum engine, I get "That is the torque for those bolts"! ARG! I may not even use them now. The won't even give a straight answer.
#17
TECH Addict
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Once again, the whole point of torquing a fastener is to apply the correct amount of stretch (preload) to it. "It" being the fastener. Any lesser value will risk the fastener coming loose, any greater value will risk breaking the fastener. The material you are threading it into does NOT come into play here. If you are worried about pulling the threads, I'd suggest you get a heli-coil kit and get after it...
Starting on page 12 of this link is a discussion what happens when the tensile strength of the bolt is too high relative to the nut to which is to be attached.
http://www.fastenal.com/content/docu...renceGuide.pdf
So, it is theoretically possible to have a bolt that will destroy the female threads into which it is tighened before it achieves a certain torque specification (based on yield strength which is what ARP uses).
#18
TECH Senior Member
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Using the GM specifications will provide the same bolt preload. However, if you lubricate the bolt where the GM specification does not require it (this includes loctite), then you are putting more preload into the bolt due to a reduction in friction and hence into the aluminum threads. This is one reason I always cringe when I see guys adding loctite/lube where GM doesn't require it as they run the risk of internal thread damage especially since most are using lessor cost and likely less accurate torque wrenches.
#19
Using the GM specifications will provide the same bolt preload. However, if you lubricate the bolt where the GM specification does not require it (this includes loctite), then you are putting more preload into the bolt due to a reduction in friction and hence into the aluminum threads. This is one reason I always cringe when I see guys adding loctite/lube where GM doesn't require it as they run the risk of internal thread damage especially since most are using lessor cost and likely less accurate torque wrenches.