: Torque Spec for ARP Studs in Northstar



PTMech
08-08-12, 05:05 PM
I am new to the forum but have been reading the myriad of threads on head gasket repairs. I am going to be doing a repair on a 2002 LD8 DeVille. I will be using Norm's inserts with ARP 141-4204 studs.

The question I have is:

What is the preload torque specification on stud nuts for bolting the head on a 2002 LD8 Northstar? I have seen 70, 75 and 80 ft-lbs talked about in the forum threads; ARP’s 141-4204 spec for the Chrysler/Dodge 2.4L DOHC 4-cyl is “three equal steps to 85 ft-lbs.” Does anyone know what the best torque specification should be?

Thanks

Submariner409
08-08-12, 07:34 PM
You're dealing with either a recommended initial lb/ft torque preload followed by a set "degrees" sequence OR an increasing sequence to a final torque........

Call either Jake Wiebe at www.northstarperformance.com (http://www.northstarperformance.com) or Tim Carroll at www.carrollcustomcadillac.com (http://www.carrollcustomcadillac.com). They are both manufacturers/suppliers of high quality cylinder block/head studs. Absent info from them, get into ARP's site and ask the OEM..............heck - ask Norm Huhn what he thinks about torque settings.............. www.huhnsolutions.com
(http://www.huhnsolutions.com)

Ranger
08-08-12, 10:27 PM
Use the inserts or the studs Sub mentioned. I don't see the reason for the redundancy.

PTMech
08-09-12, 11:06 AM
Use the inserts or the studs Sub mentioned. I don't see the reason for the redundancy.

Thanks for the feedback. I am installing the ARP studs into inserts similar to head bolts since I am doing a repair. Since I will be torquing nuts on studs in lieu of head bolts, my question centers around incremental step to final torque load, not torque / angle. Jake's instructions say 75 ft-lbs. for his studs. I have also seen 70 and 80 ft-lbs. in different threads on this forum for stud nuts. ARP's instructions state 85 ft-lbs. for the 141-4204 stud nuts in a Chrysler/Dodge application.

With all the different torque loads stated, does anyone know the correct one for the LD8 engine using studs and nuts in lieu of torque/angle head bolts?

Thanks

Submariner409
08-09-12, 06:58 PM
Most of us are pretty familiar with Norm's NS300L inserts and/or studs. Those inserts with ARP studs is a perfectly legitimate way to repair the 20 holes in a Northstar block. Yes, it's block threads, insert threads, stud threads, but the stud going into the insert could care less: it's steel into steel. The beauty of the studs in either configuration is the fine upper threads: you can sneak up on the proper torque VERY accurately. I use 85 lb/ft in my studded Olds 455 iron blocks with ARP 7/16" studs, so (and this is a guess) 80 lb/ft in 3 crisscross steps - 30, 60, 80 should be just fine for a NS300L inserted aluminum block.

I would use the time-honored several drops of engine oil on the stud upper threads/nut/hardened washer during torquing. The Olds engine manuals say to either dip or drip engine oil on the head bolts prior to installation. ARP has their own recommendations for torque settings when using their assembly lube.

(With the original small/fine thread Timeserts, all bets are off.)

PTMech
08-10-12, 11:03 AM
Thanks for the advise.

stoveguyy
08-10-12, 12:34 PM
R norms inserts designed to be used with standard head bolts?

Submariner409
08-10-12, 12:42 PM
Yep. His applications and kits give instructions on the proper head bolt to use. The ARP studs in question (as well as their earlier Volkswagen studs, also usable in the Northstar) use the same cylinder block thread as our stock Northstar, so they're a direct drop-in to the inserts. Jake's and Tim's studs are made with the huge (newly machined) coarse block threads, so they WILL NOT screw into a non-machined Northstar block, nor will they screw into an insert.

IXSLR8
08-13-12, 05:04 AM
I have Norms inserts, ARP studs, and Cometic gaskets in my 1996 engine. I torqued the studs to 75ft. pounds after talking with Cadillac Hotrod Fabricators. I did three equal torque events to 75ft. pounds. Haven't had a single issue with the setup and its a daily driver.

Submariner409
08-13-12, 10:37 AM
^^^ That's better info than my guess ^^^

Thanks for the comeback.

PTMech
08-14-12, 01:48 PM
Great. Thanks for the info.