ARP Head stud stretch question.........

[fastasleep]

I am using my ARP 11mm head studs for the third time. As I am tightening them to 85 lbs./ft., a few of them stretched like hell and never attained proper torque. I am using ARP lube on the studs and am torqueing them in steps (50-70-85). Am I doing something wrong or have I just used them too many times?

-Les

[tsiconquest88]

Honestly i think the most amount of times ARP suggests to re-use their studs is 3. Re-usable to around 3 times. you probably didnt do anything wrong, and i would never re-use anything bolt or studs. But thats just me. I figure if im goin the extent for a rebuild i just go new ARP studs, i have went on 4 sets for 4 different builds and maybe one or more of the sets could have been re-used i dont take the chance. But yes use a little of the moly lube on the washers and threads a little, dont have to go crazy as you dont want to cause the threads to actually not bottom out, this causes hydrolock. The space taken up during expansion of the heat and all of the block could crack the block where the threaded holes are that the studs are in.

[fastasleep]

The space taken up during expansion of the heat and all of the block could crack the block where the threaded holes are that the studs are in.


I guess that is why the instructions say to only hand-tighten. Thanks for the tip; I think that I will just order another set. The funny thing is that I have had the engine built three times but haven't put very many miles on it at all. There is always something more that I want to do. Very good! Thanks, man.

-Les

[tsiconquest88]

thats the exact reason for the hand tightening, BUT i have seen it still happen. And i know of an old mopar TSB on using head studs that someone i know of posted on a SQ site. Tells a lot of useful info for using head studs with its lube. I posted it below.

[BadAssPerformance]

Check each stud's diameter with a set of calipers at various lengths along the stud shank. As long as the diameter is constant (read: no necking down) then they have not yeilded. Look at the threads on the stud and in the nuts for damage. If everything looks ok, then I would say that they are ok. While you are at it, check teh threads in teh block for damage. A big +1 on finger tight into the block, heck loose is ok as long as they are in far enough!
I have re-used ARP studs many times w/o issue. Also 85ft-lb with the moly lube seems on the high side?

[tsiconquest88]

In the mid to late '60's Mopar Direct Connection came out with special head studs to replace the head bolts for the Hemi, B & RB engines. All of a sudden SOME racers (especially the street racers) who used these head studs started blowing head gaskets and in some instances cracking blocks similar to what your block has done. There was quite an uproar in the Mopar racing circles.

As a result, Mopar came out with a TSB which analyzed the cause of the failures and gave guidelines for the installation of the studs.

To make a long story short, it amounted to how much torque was applied to the studs as they were seated (bottomed out) in the threaded head stud/bolt holes.

Those that experienced block cracking:
Mopar hypothesized that they were tightening (bottoming) the studs too tight in the head stud holes. Then, as the engine heated up due to the difference in expansion rates between the stud and engine block (studs expanded more than the block) it put extreme pressure (stress) on the block casting in that area and over a period of time (depending on how tight the studs were) a crack(s) would develop and propagate in the direction of the block that had the least meat around the threaded stud hole.

Those that experienced head gasket failure:
Mopar hypothesized that:
A) The studs were too loosely seated, or not seated at all, in the bottom of the threaded head stud holes. This caused, over a period of time, the studs to further loosen due to heating up and cooling down of the engine and/or the stresses induced by high compression ratio's (some guys were running 13.5/1 back then).

2) Too much lube was used on the threaded portion of the studs. As the Anti Seize lubed studs were screwed into the stud holes it, in some instances, the lube globbed on the bottom of the stud; or in the case of using engine oil as a lube, dripped into the bottom of the stud hole. This caused the stud to not fully bottom in the threaded hole. It caused a hydraulic lock preventing the stud from bottoming correctly. Over a period of time the stud would loosen. Or in extreme cases, (ie engine overheating) cause cracking of the block due to the engine oil lube heating up and expanding causing extreme stress at the bottom of the hole below the stud.

C) The head seating/mating area to the head stud nut washer (or the washer itself) was gauled, fretted, or not perpendicular to the centerline of the stud. Or the mating surface on the underside of the nut had the same defects.

D) Too little, the wrong kind, or no lube was used when screwing in the studs into the block's threaded head stud holes. Consequently the studs may not have bottomed out correctly.

E) The block's head stud hole threads were not properly chased with a starting tap and then chased with a bottoming tap. Also, not all of the tap shavings were removed from the bottom of the taped hole or threads. Each of which could cause the studs to not properly bottom on the threaded holes. Or the studs and/or nuts had defects in the threaded areas.

F) The head nuts were torqued using an improper torqueing sequence. Mopar specified cross bolting as was shown in the FSM and RE-EMPHASIZED that the torqeing MUST be done in "several" 10 to 15 FT LB incremental steps until the final desired torque value was EVENLY achieved.

G) A NEWLY calibrated torque wrench was not used during the torqueing of the head nuts; IE the torque wrench was out of calibration.

As a result of the above Mopar stated:

1) Proper lube for to be used for screwing in the head studs/nuts was Molybdenum Anti-Seize, used evenly and judiciously in the threads. For some reason they did not include the Copper based Anti-Seize.

2) The PROPER head stud bottoming torque was FINGER TIGHT!! Ensuring that: 1) the the threads were clean/ and properly chased 2) no shavings/crud are in the threaded holes as stated above and the studs properly lubed.

3) A visual inspection of the head mating/seating surface to the head nut/washer assembly and the head nut/washer themselves must be made to verify that there are no defects. If any are noted, that component must be replaced, or in the case of the head seating/mating to nut assembly surface dressed or machined properly.

4) Each of the new head stud's nuts, with the head installed, but no head gasket, were to be properly fully torqued 3-4 times to "set" the stud, PRIOR TO FINAL head installation. These Mopar studs were "resuable," although we replaced them during every race engine tear down.

5) They also included the proper stud stretch values to be used for verifying that the proper torque was achieved for the desired torque value. Plus the maximum stretch before you had to trash them.

6) Ensure that a NEWLY calibrated torque wrench was used during the torqueing of the head nuts.

7) Retorque the head nuts in the proper manner using the correct sequence after the engine was heated up to normal operating temperature, run hard, and then cooled down 3-4 times; using their suggested head gasket.

Mopar included this TSB in EVERY box of head studs that they sold after it was issued.

[BadAssPerformance]

Interesting info! Good Info for the KC! :thumb:

[tsiconquest88]

and yea BadAssPerformance is right, you can check them i just dont and buy new. also like he said check and even chase the block threads, as doing that in any engine is a good idea when doing a head, and i always flush the heck out of each hole, chase and then flush to get the junk out, as much as you can. Then as u put the studs in u will usually get some more stuff to squeeze out and you wipe that away too. Brake parts cleaner is great for all this as it disipates quickly even in marge amounts of it in the bottom of the threaded hole, And helps the gunk press up to the top once the stud/bolt is run into the block. chasing dont do this really the way a used bolt/stud does. But chasing breaks up everything for sure and cleans the threads. I also make sure no chemicals are on the deck surface prior to gasket by using the brake parts cleaner and wiping completely clean after its inital full cleaning and even if its been resurfaced. Can never be too sure.

[tsiconquest88]

Yea i figure you guys here might be able to benefit from that. And it fits so well in the Mopar community hehe.

[BadAssPerformance]

Hell yeah!

and +1 on brake cleaning the heck out of the holes!

[fastasleep]

The stud is definately longer and does neck down. I can see it with my naked eye although I did mic it and there is a decreased diameter in one of the studs. There is discoloration where the decreased diameter is as well.
I guess my torque wrench could be out, but I checked it again using an analog torque wrech and it just would not hold 80 lbs./ft. without strectching.
Thanks for the info, too. That is a good read. BTW, I did chase all the holes with a bottom tap and I always use ether to clean mating surfaces.
I was putting a new 005 gasket on. I didn't get it fully torqued. I wouldn't think it would be an issue to get new studs and crush it all the way with new hardware?

-Les


-Les

[turbovanman²]

ARP will replace those for free, thats bad press for them. Studs are supposed to be reusable, and way more than 3 times, :(

BTW, I reused my 8 valve set at least 15 times and still good when I sold them. My 16 valve set, probably 10 and still good. 85 ft/lbs is perfect, by the by.

I always tighten mine down, then back off 2 turns, then hold them as I snug up the nut.

[tsiconquest88]

hrm im pretty sure recomended i have seen 3 times re-used?? Sorry for any mistaken info there if im wrong... but anyway, do the rest of the stuff, badass, turbovanman, and i said. As well as stuff in that TSB.

[fastasleep]

I just ordered a new set from Chris, but how do I go about getting them replaced by ARP? The truth is that I followed procedure, except that I have not had my torque wrench calibrated in over a year. That could be a pitfall. What do you think I should do?

-Les

[tsiconquest88]

An in spec torque wrench is definately critical (for you and your engines sake). However as for this replacement thing idk nuthing on that.

[fastasleep]

I used the ARP customer service and sent an e-mail. We will see. I did tell them that my torque wrench had not been calibrated in over a year, so they may hit on that. Dunno, but I already have a set on the way JIC.

-Les

[turbovanman²]

I just ordered a new set from Chris, but how do I go about getting them replaced by ARP? The truth is that I followed procedure, except that I have not had my torque wrench calibrated in over a year. That could be a pitfall. What do you think I should do?

-Les

Phone ARP and tell them.

I've put mine to over 100 ft/lbs, no problems.

[tsiconquest88]

Yea i too had done 100 Ft pounds on the first set i used then there was a change in the info and said 85 with the lube for my engine and i unidid it all and got a new gasket etc, checked the studs and they were all fine. I forgot all about that, so i technically have re-used studs even though i didnt run the motor yet haha.

[Directconnection]

hrm im pretty sure recomended i have seen 3 times re-used?? Sorry for any mistaken info there if im wrong... but anyway, do the rest of the stuff, badass, turbovanman, and i said. As well as stuff in that TSB.

They get re-used waaay more than 3 times at our shop. No issues ever.

We finger tighten them down, but the odd thing that contradicts the "finger tight" procedure is that when you torque the nuts, it winds down the stud to some degree. And, the sucky thing is when you loosen them up, it unscrews the stud, too... (pita!)

The "stretch" feel you may be encountering might be the stud actually winding in giving you a false feeling. But, studs do have a springy feel unless 1/2" like what I am used to using (BB Chevies etc..)

[tsiconquest88]

i wasny experiencing a stretch, i was just tellin the guy who made this thread that i dont re-use the studs. Just my preference, then its one less thing to wonder WTF happened if something were to occur lol.

[Directconnection]

i wasny experiencing a stretch, i was just tellin the guy who made this thread that i dont re-use the studs. Just my preference, then its one less thing to wonder WTF happened if something were to occur lol.

When I said we re-use them indefinately... I was talking to you. When I mentioned the stretch issue, I was talking to the original poster :)

Rod bolts.... we replace after a few seasons.... that's an area you don't fawk around with. We build the ZZ4 crate engine for the PASS/ACT racing program. They come with stock bolts, and after 2 seasons or so, we get the engine for a refresh. We re-size them with new ARP's and it's run for another couple seasons. Comes back in for another re-fresh and we just check the Hb's with the now used ARP's. If the stretch is ok, and the HB size is ok, they are good to go for another season or two. Usually when they come back in again, they get a whole new set of rods with stock bolts and we start the game all over again. Some ZZ4 crate engines (sealed crate engines) get re-freshed every season.

[4 l-bodies]

Also 85ft-lb with the moly lube seems on the high side?
I agree with JT on the torque spec is on the high side. On the back of every ARP head stud box has a recommended torque chart with 30/wt oil and ARP lube.
Specs for 11mm studs is 71 lbs with ARP lube. Where are you getting the 85lbs spec from? I've never had a problem with ARP studs stretching. Or head gasket lifting (except with those 85 10MM blocks). Better get that torque wrench recalibrated.
Todd

[turbovanman²]

I agree with JT on the torque spec is on the high side. On the back of every ARP head stud box has a recommended torque chart with 30/wt oil and ARP lube.
Specs for 11mm studs is 71 lbs with ARP lube. Where are you getting the 85lbs spec from? I've never had a problem with ARP studs stretching. Or head gasket lifting (except with those 85 10MM blocks). Better get that torque wrench recalibrated.
Todd

85 ft/lbs is the magic number we've all been using. Stock is around 95 if memory serves.

[fastasleep]

Yeah, I got the 85 number from the write-up Simon did; I just did a search on "ARP head stud torque". I have had these for only a little while, but I could not find the original instructions so I looked on here.

-Les

[BadAssPerformance]

I never went up to 85 until I was holding 30psi boost...

[puppet]

I agree with calling ARP. Sounds like a few studs not up to spec to me. .... or somebody put a torch to them at some point?

The studs they make for us are undercut so they will exhibit some stretch between the threaded sections. That's the design ... but they should return once the stud is loosened.

Our torque values ... listed on ARP's site, and the box ... 90lbs w/30wt oil ---- 71lbs w/moly lube. As per ARP, tighten to values (3) times before final sequence ... (there goes the "use only (3) times theory). ARP bases these values on OEM spec's largely so gasket choice plays a factor in them. The undercut in our ARP's gives more flexibility to the stud needed with the aluminum head. Tightening these studs too much negates that feature. I'd only increase the torque slightly if you're blowing gaskets at the recommended torque levels. Otherwise, you're over streching the stud and it can't compensate for the heat expansion of the head. BTW ARP states that these torque values are 75% of their studs rating. Do the math to see the limits.

[fastasleep]

When I tighten to value three times, does that mean torque the nuts in the proper sequence and then loosen in the proper sequence and repeat?

-Les

[BadAssPerformance]

no, you never loosen.

For example factory head bolts are 45-65-65 + 1/4 turn... you tighten (in sequnce) to 45, then to 65, then again to 65, then 1/4 turn, never loosen until you want to put the next head gasket on.

[4 l-bodies]

85 ft/lbs is the magic number we've all been using. Stock is around 95 if memory serves.

Simon,
Apparently not all of us.:p Stock is using head bolts and the torque to yield 45/65/65 + 1/4 turn method. Different animal. Gary D. I believe came up with the ft/lb number for what a stock bolt should yield.
Yeah using my highly inaccurate Craftsman microtork wrench I would have to tighten them to a zillion foot pounds. Using my Snap-On or Proto calibrated torque wrench and 71 lbs/ft works for me. If he's stretching studs, that's a sign of bad technique or something is wrong with the product.
Todd

[fastasleep]

So do I need to get a new 005 head gasket? This is a new one, but as I was torqueing the nuts, I noticed the stretch. I disassembled. Can I re-use the 005 hg? Also, I have a cometic. What procedure is needed to reuse? Clean and reinstall? Coppercoat?

-Les

[puppet]

no, you never loosen.

For example factory head bolts are 45-65-65 + 1/4 turn... you tighten (in sequnce) to 45, then to 65, then again to 65, then 1/4 turn, never loosen until you want to put the next head gasket on.
Actually you do loosen then retighten (3) times .. this is on a set of new studs though. A gasket doesn't "set" till engine is run.

[turbovanman²]

no, you never loosen.

For example factory head bolts are 45-65-65 + 1/4 turn... you tighten (in sequnce) to 45, then to 65, then again to 65, then 1/4 turn, never loosen until you want to put the next head gasket on.

As puppet said, yes you do for new ones, just like rod bolts. That 1/4 stuff is for stock bolts, not studs.


Simon,
Apparently not all of us.:p Stock is using head bolts and the torque to yield 45/65/65 + 1/4 turn method. Different animal. Gary D. I believe came up with the ft/lb number for what a stock bolt should yield.
Yeah using my highly inaccurate Craftsman microtork wrench I would have to tighten them to a zillion foot pounds. Using my Snap-On or Proto calibrated torque wrench and 71 lbs/ft works for me. If he's stretching studs, that's a sign of bad technique or something is wrong with the product.
Todd

I got 85 ft/lbs from most of the high hp guys from here, don't shoot the messenger, ;)

Gary came up with 95 as I believe he used a torque wrench and did the stock tighten proceedure and it was close to that when finished.


So do I need to get a new 005 head gasket? This is a new one, but as I was torqueing the nuts, I noticed the stretch. I disassembled. Can I re-use the 005 hg? Also, I have a cometic. What procedure is needed to reuse? Clean and reinstall? Coppercoat?

-Les

I would or maybe tighten them to 90 next time. Cometic, clean, degrease, spray with copper spray, tighten down.

[t3rse]

I tightened arp to 90...anything less and the gaskets would blow too easy in my case

[Frank]

Article added. :) http://www.turbo-mopar.com/forums/vbarticles.php?do=article&articleid=128

[tsiconquest88]

cool, i think many people will benefit from that. Any engine using head studs for that matter. With possible varying torque ratings being the only difference between applications.

[BadAssPerformance]

Interesting... I've never loosened ARP head studs and never had issue... I do always re torque after heat cycle tho.

[Juggy]

I torqued to ARPs recommended specs and lifted the head, which in turn blew out the headgasket in all 4 cylinders, and the fire escaped and burnt the head outside of the ring, had to have it shaved .011"

will be torquing to 85fpt now!

[turbovanman²]

Interesting... I've never loosened ARP head studs and never had issue... I do always re torque after heat cycle tho.

I have never done that for head studs either, just rod bolts, never retorqued either, too lazy, :p

[tsiconquest88]

haha, technically ur not suppose to even have to re-torque them, re-torquing is usually for certain headgaskets that require it. BUT it never hurts to do after a full warmup and little boost after the frist drive with a fresh job.

[contraption22]

I have reused my studs more times than I care to count, and have never really given it a 2nd thought. I have not had an issue achieving recommended torque. But now you have given me one more thing to worry about! Thanks! lol

[fastasleep]

No problem! :) I sent them back off to ARP. I also sent my torque wrench off for a cal. and to see how far (if it was) off.

-Les

[Mike_Shepard]

I think I to have fallen victim to a faulty torque wrench :( brand new gasket and 5psi and I have seepage coming out from 2 , 3, 4. So now a new gasket is in order along with a calibrated wrench

[tsiconquest88]

hows the head? warped? was it checked?

[Mike_Shepard]

It was sent to a machine shop an checked yes. The seepage isnt really that bad but its there and I cant have it.

[tsiconquest88]

yea its only gonna get worse anyway. definately gotta get it done.

[WickedShelby88]

Was hoping to find the actual method in which to torque ARP bolts here. I just bought a used set of studs. I do have a st of new ARP rod bolts ready for a friends engine, but obviously the instructions wouldn't apply there.
So does anyone here have the instructions in which to tighten down ARP studs lying around? Also ARP's site even recommends to re-torque the head bolts or studs after the engine has been run. Basically I am just looking for specific application to our cars.

[tsiconquest88]

well actually u need to torque in the sequence the oem manual tells u for any head. The only difference is whatever tq is required for the ARP in this case people say 85 ft pounds for these studs in these heads so in turn u would do the oem sequence in 3 steps so 85 in 3 steps is once at 30 then 30 then the remainder 25 would be fine. u just take wutever total tq and split it into 3 of the closest ranges u can, u dont gotta narrow down to make it exact all 3 as u can see i didnt, u could get it exact for all 3 by dividing it up better but its not necessary.

[WickedShelby88]

I also noticed though that in ARP's catalog it doesn't even have a listing for head studs for our turbo cars. It specifies non turbo beside 2.2. Are these a one off product sold through our vendors?

[BadAssPerformance]

... I just bought a used set of studs. I do have a st of new ARP rod bolts ready for a friends engine, but obviously the instructions wouldn't apply there.

check the used studs for yeilding

the 2.2L studs are a standard ARP part number.

[WickedShelby88]

I will definitely check them before I use them. I wonder if ARP will warrant them if they are in fact faulty. From what I understand they were only used once.

[BadAssPerformance]

They are probably ok unless over torqued... ARP wont warrany misuse. Are these going in Jim's engine?

[turbovanman²]

I will definitely check them before I use them. I wonder if ARP will warrant them if they are in fact faulty. From what I understand they were only used once.

From what I've read and been told, they will warrant almost any failure, as a failure of any kind looks bad for them, ;)

[WickedShelby88]

They are probably ok unless over torqued... ARP wont warrany misuse. Are these going in Jim's engine?

I don't think they are over torqued, but as stated I should check regardless. No on Jim's engine. I am buying new MP head bolts.