Another Head Stud Question...

[Luke]

When using APR head studs, I see many threads instruct you to remove the black oxide coating on the threads. The ARP instructions don't mention anything about this step. The only reason I can figure people do this is possibly so the thread sealant bonds to the threads of the studs better. Is this the case?

 

[Luke]

Anyone?

 

[S10xGN]

I've been here 10 years and never saw this mentioned! Just be sure to torque-cycle them 5 x's (if new) and use the appropriate sealant.

 

[Luke]

Here's an example...

You'd think you should follow ARPs instructions to the tee! But it's when you read articles that say things like "I can only imagine following the ARP instructions and using their brand sealant only to take things apart and see this mess", that you really start doubting things...

TurboBuicks.com - Head Studs That Don't Leak!

 

[84BuickGNYorkPA]

I followed the above instructions stated. Except the wait part on the sealer, I torqued the heads to 70 #(using ARP Molly) let is sit for 24 hrs and re-torqued to 70# also at the same time re-torqued the intake bolts too. Now a week later and about 200 miles, undicided if I need to re-torque again, can someone tell me if it is necc. to re-torque?

Chuck

 

[S10xGN]

You'd think you should follow ARPs instructions to the tee! But it's when you read articles that say things like "I can only imagine following the ARP instructions and using their brand sealant only to take things apart and see this mess", that you really start doubting things...

TurboBuicks.com - Head Studs That Don't Leak!

Mike's a pretty savvy guy, but I've never heard of removing the black oxide coating and have no idea what the benefit/detriment could be. It's not mentioned in any of ARP's official publications. I've built plenty of engines using ARP studs and have never done it... IIRC, I used Loctite's teflon sealant and still needed a few GM seal tabs to kill the weepage.

 

[84BuickGNYorkPA]

Mike's a pretty savvy guy, but I've never heard of removing the black oxide coating and have no idea what the benefit/detriment could be. It's not mentioned in any of ARP's official publications. I've built plenty of engines using ARP studs and have never done it... IIRC, I used Loctite's teflon sealant and still needed a few GM seal tabs to kill the weepage.

I read on another post it is done so the sealant would bond better to the threads and help prevent leaks. It makes sence to me since the coating is as smooth as a baby's bottom, removing it gives the sealant a rougher surface to grip/seal.

Chuck

 

[Terry_H]

Technically, when removing coatings and adding sealers, you alter the torque specs somewhat.