[RPM]

What is the torque value for ARP main studs (2 bolt) using their assembly lube?

[RPM]

What is the torque value for ARP main studs (2 bolt) using their assembly lube?

[Guy Mazza]

RPM, I torque the ARP studs (2-bolt) to 100ft/lbs and the #5 cap bolts to 120ft/lbs.
Hope this helps, Guy

[77TA]

my information here says 83ft/lbs with arp lube and 102 with oil. on the front ones 1/2"
they are fine threads you get more stretch with less tourqe as compared to course thread stock bolts.

[RPM]

I waited on an email reply from ARP gave up and called them. They said using their assembly lube 99 ft/lbs on the 1/2" studs and 130 on the rear cap. 77TA, what info do you have that says 83 ft/lbs?

[KEV]

Hey RPM! Well that is interesting info you got. I JUST bought these from Summit yesterday. The documentation in the box says...

1. install the stud in the block hand tight

2. 1/2" diameter torque to 90 ft lbs with the supplied ARP molly lube. With 30 wt oil, torque to 130 lbs. The also warn against using any other brand of molly lube.

3. 9/16" diameter torque to 115 lbs with ARP molly lube and with 30 wt oil 180 lbs.

Again this is the info right out the box. Hope this helps.

Kev

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Kevin Swaney
Gold '66 GTO powered by a 389 with Trips
with 4 spd 13.042 @ 106.64 mph
with TH350 12.511 @ 106.91 mph ** NEW LOW!

[PROBRD]

Just checked the directons that came with mine. Ditto to what KEV said. Exactly right.

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1/8th mile 6.56 @ 104
1/4 mile 10.43 @ 127

[RPM]

Thanks Kev! Man! you call ARP tech for help on one of their own products and they just pull a number out of the air. What a phuckin joke!

[Skip Fix]

You are right about gettinbg different number from ARP tech guys. I bought some of their bolts to use for the mains and got 5 different answers(their catalog does have a chart) so I ended up keeping the stock bolts. I didn't want to not torque them enough to keep the correct stretch. Their different quality bolts take different torques.

[Half-Inch Stud]

I bought main studs [for 4-bolt caps] in 1987 and found that most folks [Speed shops] didn't give a care to the fine thread needing less torque to have the same clamping pressure [or same holding pressure]. They blindly recommended the factory torque values...[in our case large-journal blocks with stock bolts: 100ft-Lbs, and Rear 120Ft-Lbs]

Back then, I had a Mech-Engr run the thread-pitch calcs and we came up with slightly lower numbers. Also factored-in the hard-washers with polished [low-friction surfaces]. The studs held admirably at the lowered torque.

Should be spelled-out to all folks here: While applying torque to the nut, the nut runs a significantly shallower thread ramp, and applies more clamping torque [stress on the main webs]. The coarse threads [stud and main web]within the block will see clamping forces that exceed 'stock' if the fine thread Nut/Stud is torqued to 'stock values'.

Key issue is: too much bolt/stud tension equates to less holding PSI for the pavement-pointing forces from the crank to the caps.

OK, said my piece...that was aimed at all the folks [probably none on this site] that gloss over details.

Wish I could recall the torque levels. Sorry. Somebody chime in.

P.S. Can anybody relate to how silly I felt putting studs to the outer holes on 4-bolt caps. Talk about useless and stupid. Not worth the risks on possibility of error.
Use cap-bolts on the outers.

[Tim Corcoran]

When torquing mains you need to use the exact same torque and lunbricant that was used when the mains were line honed. This will insure they stay round under torque.

Even more important to do this on rods.

Tim Corcoran

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65 LeMans 11.13@120
going into the 10's
this winter