ARP head studs

Mike92104 · **Posted:** Fri Sep 05, 2014 11:40 pm

I included the ARP studs in my engine rebuild.

rancherman · **Posted:** Sun Nov 09, 2014 11:20 pm

greiswig wrote:

Okay, dumb question time:

The ARP studs have two different types of threads. Coarse to mate with the block, and fine up above where the nut threads on.

I would guess that the torque spec is thinking that the nut is spinning against the stud, correct? But if you can't bottom out the stud, it would be free to move as well. And since the thread pitch is different, torque applied in that case would mean a different clamping force, wouldn't it?

Put another way, if I have one fine thread bolt and one coarse and apply the same torque to each, which one has greater clamping force? The fine thread one, right?

What, me worry?

To answer your last question properly, Yes. The fine thread fastener with the exact same lubricant will have approximately 50% more clamping pressure than its coarse threaded counterpart. Assuming same torque was applied to each.
This engine, and some Fords are the only engine I've ever seen with coarse thread headbolts. *aluminum blocks don't count here*... fine threads are not used then.
..... which is easier to walk up?? a steep ramp, or a nice shallow incline? same with the fastener... the fine pitch will 'win out' every time... and the coarse thread won't budge while torqueing.

taroo · **Joined:** Sun Apr 27, 2008 2:14 pm **Posts:** 271

When installing ARP studs, what lubricant should I use on the threads?

geordi · **Posted:** Sat Nov 15, 2014 8:39 pm

For the threads that go into the block, nothing. No lubricant it all on that end? ARP provides their own lubricant for the nuts and the fine threads and the washers. Use it everywhere.

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rancherman · **Posted:** Sun Nov 16, 2014 11:32 am

taroo wrote:

When installing ARP studs, what lubricant should I use on the threads?

ARP RECOMMENDS using their lube on the block end too.
I've used lube on both ends for years. Why?
makes it easier for removal next time, There's ALWAYS a 'next' time. I'm not talking about the effort to spin them out.. I'm talking about not hurting the threads on the block!
And, it helps with the 'galling in' part. You have a wear area here! Iron and steel together. Sure, they are not moving, but There is SOME changes, microscopic sure, and it takes time for it to happen. Lube here all but eliminates that.
Use just enough to make it look 'wet'. You don't want to hydraulically split the hole!
Yes, even 'hand tightened' studs can do this (with enough lube under them).. Oil will expand when hot, and poof! ya got problems
While these problems are not guaranteed to happen each time, why take the chance? 1-2 drops on each stud is what they say? 'ounce of prevention'.
OH, btw, make sure you lube both sides of the washer too.

flman · **Posted:** Sun Nov 16, 2014 7:49 pm

I followed the ARP instructions, dry into the block, and lube on nuts, threads and both sides of washers.

rancherman · **Posted:** Sun Nov 16, 2014 9:55 pm

Interesting! ^^^^
Last dozen or so sets I've installed on various engines all recommended their lube on the block end too..
Possible the coarse thread here isn't as 'particular' as normal 'fine threaded' situations!
So, if this app specs NO lube, then so be it! :rockon:

flman · **Posted:** Mon Nov 17, 2014 6:09 pm

Rancherman you proved us wrong, the instructions in the box are kind of vague, but here they say lube all the treads.

http://arp-bolts.com/p/FAQ.php

Sleeper · **Posted:** Mon Jan 19, 2015 2:25 pm

So is the latest wisdom on the torques for ARP studs still 130 inner/125 outer (ft-lbs)? Just installing right now.

taroo · **Joined:** Sun Apr 27, 2008 2:14 pm **Posts:** 271

Sleeper wrote:

So is the latest wisdom on the torques for ARP studs still 130 inner/125 outer (ft-lbs)? Just installing right now.

That's what I did to mine last month.

Sleeper · **Posted:** Tue Jan 20, 2015 11:15 pm

Thanks Taroo. I'll run with that.

user113 · **Posted:** Sun Jan 25, 2015 1:56 am

taroo wrote:

That's what I did to mine last month.

Congratulations, Taroo. Glad to hear that.

fast57chevrcr · **Joined:** Sat Dec 27, 2014 10:51 pm **Posts:** 3

LMWatBullRun wrote:

It will be a few months before I get any really long hot drives, but I was losing coolant on 20 to 40 mile commutes. Now I am not. Cardboard/newspaper did not show any drips. Was this the WP or the HG? Who knows? I do know that I found significant variance in 'TTY' head bolt removal torque, and significant variation in rotation required to bring the ARP nuts to the required torque. Both of these facts are strongly indicative of a warped head, but I did not gage the head to confirm it.

Bottom line, studs ensure clamping force. I will be building the next motor with them.

Thank you for all the info !!! I bought a project 2006 kj with a broken rocker arm and worn rocker arms and apart so I'm going to put studs in and not needing to remove the head as it is in good shape. Just waiting for parts to get here then I will be doing as you did.

Thanks John

gmctd · **Posted:** Wed Jan 28, 2015 12:42 pm

LMWatBullRun wrote:
It will be a few months before I get any really long hot drives, but I was losing coolant on 20 to 40 mile commutes. Now I am not. Cardboard/newspaper did not show any drips. Was this the WP or the HG? Who knows? I do know that I found significant variance in 'TTY' head bolt removal torque, and significant variation in rotation required to bring the ARP nuts to the required torque. Both of these facts are strongly indicative of a warped head, but I did not gage the head to confirm it.
This would indicate warped head only with cast-iron head - the TTY head bolts are not suitable for aluminum heads because the aluminum easily "crushes", or compresses, where cast-iron crush is measureable only with micrometer - this aluminum compression is particularly exascerbated when the originally-spec'ed hardened washers intended to reduce crush-effect are omitted, as appears to be the case in this VM engine - steel bolt to aluminum head galling resulted during bolt rotation skews tightening and removing effort

Anyone choosing to use the new oem factory TTY bolts as supplied with new head gaskets should torque them to a specific value, ~80-100ftlbs as spec'ed for other turbocharged aluminum-head engines, rather than using the Torque-To-Yield procedure - results would be much improved if using the hardened washers which also prevent aluminum galling resulted from turning\twisting torque - this will skew the tighten to torque value as well as the TTY results

Alternately, using a torque wrench, follow the TTY procedure, noting the final torque reading at the final rotational angle, using hardened washers (purchased from ARP) between bolt and head

Bottom line, studs ensure clamping force.Agreed - this is my preference I will be building the next motor with them.

Srytrucker · **Posted:** Tue Jun 02, 2015 12:31 am

I am getting my ARP studs done this week so agreed torque settings are 130 Lb/Ft for inner and 125 lb/ft for outer studs.

Dent · **Joined:** Sat Aug 04, 2012 11:05 pm **Posts:** 275

How long does the tap need to be to chase the threads without removing the head?

tomasnc · **Posted:** Wed Jun 03, 2015 6:49 am

Dent,

I pulled my head due to what I thought may have been a leaking head gasket. Anyway, I have never seen extra long taps. I'm guessing you'll need an extension. http://www.icscuttingtools.com/catalog/page_224A.pdf.
I would clean the hole with compressed air and call it done. I holes were very clean less the lube that was used in assembly

Good luck.

Tom

geordi · **Posted:** Wed Jun 03, 2015 1:27 pm

The holes in the block do not need to have anything done to them. Just put in the studs finger tight once they are assembled and the top threads, nut and washer is all lubed up.

Dent · **Joined:** Sat Aug 04, 2012 11:05 pm **Posts:** 275

Thanks Tomasnc and Geordi.

LMWatBullRun · **Posted:** Thu Jun 11, 2015 12:02 pm

Dent wrote:

How long does the tap need to be to chase the threads without removing the head?

About 6". I bought a tap, as ARP recommends cleaning the block holes, and I used it. See description earlier in this thread. ( page 4 or 5?). I also used silicone sealant on the lower threads, probably NOT needed. I'm sure lots of folks have done without the tap since I did this 3 years ago, so you may not need it, but I'd rather have it and not need it than the other way round.

ARP head studs

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