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Concern with ARP Rocker Arm Studs?

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Old 01-20-2017, 04:04 AM
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Default Concern with ARP Rocker Arm Studs?

Hey guys, while checking pushrod measurements I noticed when I torque down the rocker arms the Stud appears to be a tad short and the nut sticks up past the stud. ARP recommends to snug the studs down hand tight, which I did. Should I be concerned about this and switch back to the bolts, or back the stud out some? Part number is 234-7207
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Old 01-20-2017, 09:35 AM
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Default Nut Thread Length = Diameter

Hi, good pictures, the "rule" is thread diameter = engagement length.

I view a correct installation, you could remeasure the nut length to be sure.

Lance
Old 01-20-2017, 10:30 AM
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The first thing I would do is to make sure the nut fits in the trunion properly and that it's not riding up on the radius of the counterbore or anything weird like that.

You can back the stud out a thread or two so you have full thread engagement with the nut. Like Pantera said, be sure to have enough thread engagement in the head. I usually shoot for 1-1/2 times the thread diameter, so for an 8mm (~.040") bolt, I would want 12mm (~.480") of thread engagement in the head.
Old 01-20-2017, 10:50 AM
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Default Head Stud Installation Method

Hi KCS, you are correct as am I.

I too would want the 1.5x + engagement into the soft AL GM head material.

My answer was directed at the OP question, nut/stud engagement.
Good advice though, KCS, as I have "pulled" Crower "shaft" rocker arm retaining plates (S/S) from the end cylinders, broke the plate.

Lance
Old 01-20-2017, 02:18 PM
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Thank you guys. I will look into it once I get home from work today. I am sure it has plenty of thread engagement in the head but will check.
Old 01-21-2017, 07:34 PM
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The nut itself is completely flat with the trunnion. There are no exposed threads on the nut, all threads are contacting the threads of the stud, this is with the stud snugged all the way down in the head. At least on the exhaust side, since I had the heads ported the studs for the intake can go way down into the chamber. I will be using ARP's thread sealant for the intake side to prevent oil from seeping into the intake. So I should be good right? Also, should I add some blue loctite to be on the safe side? ARP also recommends to torque them to 25 ft lbs. as well. I would just hate for one of them to back off and start causing damage.
Old 01-27-2017, 03:04 AM
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So I backed out the studs 1/2 turn and now the top of the nut is flush with the top of the stud, I should be good there. Now does anyone have any input on if I should use Blue Thread Lock on the Nut itself?



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