Switched to ARP head studs from bolts...?

[Methodical]

I decided to switch to ARP head studs since I will be running, eventually, a 150 shot of N20. I've searched here but the threads I came across talk about proper torque for head studs. So my ?s are below. I have the ARP head studs (7/16")- P/N 254-4401 and will be installed on AFR165 heads in a 95Cobra. I called ARP but they are closed.

1. How many times should I cycle the head stud nuts after the initial installation sequence? The ARP instructions did not say but I figured it should be done because I had to do it with their bolts.

2. How long should I wait between each cycle?

3. Should I put the thread sealant on the block threads or the stud threads or does it even matter?

4. ARP says 65 for aluminum heads and 70 otherwise but I plan to go with 70 or 75. Is this good for nitrous or the heads itself?


Thanks

Al

 

[final5-0]

I decided to switch to ARP head studs since I will be running, eventually, a 150 shot of N20. I've searched here but the threads I came across talk about proper torque for head studs. So my ?s are below. I have the ARP head studs (7/16")- P/N 254-4401 and will be installed on AFR165 heads in a 95Cobra. I called ARP but they are closed.

1. How many times should I cycle the head stud nuts after the initial installation sequence? The ARP instructions did not say but I figured it should be done because I had to do it with their bolts.

2. How long should I wait between each cycle?

3. Should I put the thread sealant on the block threads or the stud threads or does it even matter?

4. ARP says 65 for aluminum heads and 70 otherwise but I plan to go with 70 or 75. Is this good for nitrous or the heads itself?


Thanks

Al

I'm happy to share a thought or two with you AL

1) I'd think a sequence of 1/3 the final torque amount for all studs ...
then 1/3 more ... then the last 1/3.

Maybe wait 10 or 15 minutes and check to see if the final value
will hold on on all studs.

2) If you want to wait a while longer and check the final value again ........
you can ... but ... I'd not think you would find any loose.

3) Putting the sealer on the stud threads that go into the block makes the
most sense to me.

4) A trend I've seen over the years is to go about 5 more on the upper row
of fasteners as when you tighten the intake ... it has the tendency to lift up
in that area.

I did talk to ARP's tech guys about my sig combo which used their bolts.
He did advise the 5 more on the upper.

btw ... don't forget to put some slickum on the washers so the turning
of the nut doesn't bind.

Again ... just my ideas here Al

Grady

 

[Methodical]

Thanks for that info Grady. Much obliged.

 

[Methodical]

FYI - I just got off the phone with ARP and the tech rep stated that they (ARP) revised their torque for the 7/16" studs. They require 80ft lb instead of the conservative (per ARP) 65-70ft lb. The tech stated that the new information is only about 1 week old. So 80 it is for me.

 

[OrangeMustangGt]

Just my 2 cents....

My current setup has survived some serious knock on boost and nitrous due to my errors...

So, i would really really reccomend what I did.

Arp Studs w/ cometic MLS headgaskets....
torque in 4 stages with tops ending at 95 fltbs and bottoms at 90 ftlbs
rtv(grey or black) the bottom of the studs....(do a real good job on the bottom holes) and make sure you have a REAL clean surface....no need to have it machined though, etc. oil the top studs with motor oil and torque, then walk away....i never had to retorque, and cometic said its not needed also.


i blew 4 hg's in a month. since i did above, its been 2 years with ZERO issues, remember i have cast iorn heads...dont know if the torques must be less for alum. heads?