Jump to content

ARP head stud help


Recommended Posts

Got my studs in the mail today! Popped it open to look it over...

 

I have a couple questions. Instructions say to chase the threads. Where can I get a chaser? Auto parts store?

 

Do any of our studs protrude into the water jackets?

 

Should I use Loctite?

 

The studs are hand tightened, then the "Nuts" are torqued?

 

Says to incrementally torque in three steps and make a final torque to 125 ft. lbs. What do I make the first 2 rounds for in torque?

 

Also included is an illustration showing that I have to machine the rocker cover at stud 24, is this necessary?

 

Anything else I need to know about installing these?

 

(D'oh! Just realized I said AEP not ARP...)

Edited by hex0rz
Link to comment
Share on other sites

  • Board Of Directors

I used this method on a Common Rail truck recently http://www.glacierdieselpower.com/images/PDFs/ARP%20Head%20Stud%20Installation.pdf

There were too many threads over on CF talking about blowing the gasket after the stud install if multiple re-torques weren't done. 

Ok.. 1 you should not need a chaser as the threads are pretty much protected from the elements (Under the valve cover) and the exhaust side bolts seemed to be sealed on the Common rail I worked on. We were able to tighten them down by hand until they bottomed out then back out 1/2 turn. 

2. No I do not believe any of the studs protrude into the water jacket. 

They say you can use loctite if yo don't ever plan on removing the studs, but I don't believe it is necessary. If you blow a head gasket it makes it a PITA to remove the studs. Once again we did not use any.

3. Yes. Going by Glacier's instructions we tightened them until the bottomed out, backed them out 1/2 of a turn and held the stud in place while hand tightening the nut. 

4. For torquing check out the link above 

5. Using Glacier's instructions is extremely time consuming and physically demanding, but well worth it to not blow the head gasket out. If you can get a couple guys together to do the torquing and releasing on each stud. Tip: Make sure when you loosen the nut that the stud doesn't back out!!

 

The truck we did this to has been running 60 psi for a couple weeks now with no problems. Ask away if you have any more questions!

Link to comment
Share on other sites

I believe some bolts/studs go into oil galleys. When I did mighty diesel head bolts, I had to suck the oil out of the bolt holes with a vacuum and compressed air, but you shouldn't have to do that with studs. I think machining the rocker cover only applies to common rails. Are you replacing one at a time? 

Edited by CTcummins24V
Link to comment
Share on other sites

I did mine 1 at a time without removing the head or replacing the gasket. I followed the sequence that they give you. You don't need the thread locker. For the studs I tightened those hand tight with an Allen wrench. Make sure you use the assembly lube they give you on the threads where the nut is going to be. Since I didn't remove my head I torqued each one to 125 ftlb. Once all of them were in I went back over them and rechecked. Then I went through and started all over again and using the sequence they give I loosened 1 at a time and re-torqued them to 125. After 1000 miles I loosened one at a time and re-torqued them all to 125 once again. It felt like it took for ever but very well worth it. 

 

As for doing any milling that is for the common rail engines not ours. 

None of the bolts go into water jackets. I do believe there are some that go into the oil jacket like CT mentioned  UT they are not under any kind of pressure so you don't have to suck the oil out it will push back into the galley where it came from.

 

Mine works well I've seen 50 lb of boost and no issues with leaks. 

Link to comment
Share on other sites

  • Moderator

I basically went with the GDP method as well.

 

My first torque was to 110#. I did them 1 by 1 at 110#, until all the bolts were replaced with studs. I then started my 2nd torque sequence, and finally the third.

 

OEM torque puts them at about 105#, which is why I started at 110#. I wanted all the new studs to be slightly tighter than the OEM bolts as I replaced them.

 

My second torque was to 117#, I then waited 15-20 minutes and did the 3rd torque to 125#. I then plugged the block heater in and let it sit overnight, and re-torqued to 125# the next morning. After driving it for 40-50 miles I let it cool and checked each one with the wrench at 125#, none moved... That's how it sat for many many miles until the head came off for a rebuild.

 

Don't locktite them. Do put them in until they bottom out and back it off 1/4-1/2 turn. I didn't chase the threads. None go into the water jacket, but yes some do go into the oil galleys.

 

 

Use LOTS, and LOTS, and LOTS of lube... you do not want any resistance. If they pop/drag during the torque sequence take the nut off and add more lube. I would order extra lube, what comes with the set isn't generally enough.

Link to comment
Share on other sites

Lightly lube the threads on the stud  going into the block too.   I mean LIGHTLY!

ARP  suggests it as well. 

reason?   a  normal bolt will   'scour' and polish it's way  home. (final resting place) That  final 1/2 turn under  tension... there's a lot going on!

a  hand screwed  stud doesn't.   It only  holds,  and it may  bite in.   Which is  fine  until  you  eventually remove it.    Galling   on the way out isn't cool.

Then as above post,     lube  on the  top threads,  between the nut and both sides of the washer.

Edited by rancherman
Link to comment
Share on other sites

  • Board Of Directors

...wow, look at this, haha. More than one way to skin a cat, again. :duh:

There always is! I only did it this way because of the horror stories about putting them in then blowing out the gaskets. To each his own I guess, but because it worked so well this time I will be doing the same thing when I install studs.

Link to comment
Share on other sites

Doesn't   ARP  suggest  a  3X   torque-relax,   to  pre stretch and  work harden  their hardware? (new hardware only)     Not talking about  torqueing   in  3 stages (which I do) I run  4 laps  on the  903..   but  actually   torqueing  a  stud to full torque,  release,   torque, release, torque release  and  the final  torque.   After ALL THAT  the  fastener Is considered  " set"        It  is  a  pita  physically!  Ya better  eat your Wheaties!

We do this  on all rod bolts that are brand new... 

Link to comment
Share on other sites

There always is! I only did it this way because of the horror stories about putting them in then blowing out the gaskets. To each his own I guess, but because it worked so well this time I will be doing the same thing when I install studs.

 

How often has this happened?

 

Doesn't   ARP  suggest  a  3X   torque-relax,   to  pre stretch and  work harden  their hardware? (new hardware only)     Not talking about  torqueing   in  3 stages (which I do) I run  4 laps  on the  903..   but  actually   torqueing  a  stud to full torque,  release,   torque, release, torque release  and  the final  torque.   After ALL THAT  the  fastener Is considered  " set"        It  is  a  pita  physically!  Ya better  eat your Wheaties!

We do this  on all rod bolts that are brand new... 

 

The instructions provided tell me nothing about re torquing. All they say is to follow manufacturers torque specs and tighten them in 3 even sequences with the last sequence to 125 ft.lbs.

 

So I assume what they are saying is to follow head stud torque sequence that dodge did for head install except the last torque sequence is what ARP recommends, to 125 ft. lbs.

 

:think:

Link to comment
Share on other sites

  • Board Of Directors

Doesn't   ARP  suggest  a  3X   torque-relax,   to  pre stretch and  work harden  their hardware? (new hardware only)     Not talking about  torqueing   in  3 stages (which I do) I run  4 laps  on the  903..   but  actually   torqueing  a  stud to full torque,  release,   torque, release, torque release  and  the final  torque.   After ALL THAT  the  fastener Is considered  " set"        It  is  a  pita  physically!  Ya better  eat your Wheaties!

We do this  on all rod bolts that are brand new... 

From ARP's instructions NO but they really should! Check out the link I posted. That is exactly what you are talking about.

 

 

How often has this happened?

 

 

The instructions provided tell me nothing about re torquing. All they say is to follow manufacturers torque specs and tighten them in 3 even sequences with the last sequence to 125 ft.lbs.

 

So I assume what they are saying is to follow head stud torque sequence that dodge did for head install except the last torque sequence is what ARP recommends, to 125 ft. lbs.

 

:think:

I think this month there were 2 or 3 over on CF.

The instructions don't say to do it, and I know "ARP knows best it's their product" gets thrown around, but the work hardening rancherman is talking about is 100% true. The bolt WILL stretch after the first install... So either you re-torque them after some heat cycles or you can do as suggested by Glacier's instructions. Oh and tighten those puppies down to 135  :thumb1:

Link to comment
Share on other sites

Man,   I woulda  sworn  I seen a  'recommended'   stud    install on the  ARP  site    about    the   3X      'wake up'     for      bringing a new  stud into service.     They have  a lot of  pages,  tabs  to  cruise through,  and  I couldn't find it   again.     

I may  have used the wrong  term..   'set'  may not be  correct.    We still want    elasticity  so   the  bolt or stud  wants  to  keep  pulling the  object  down... no matter the  conditions or  cycles.       'waking up' or  'exercising'     might  be  a   better,  non  scientific  term!      Work  strengthening??

 

The   3  layer   sequence  is   a  must    for  getting the head  clamped down evenly...      This ^^^^^   is    for   bringing a new fastener into service.

Now,  a  connecting rod  isn't   a  typical  rigid  joint.  (like the  cylinder head)    there are  forces and  pressure vectors  in play  that  are not  like the cylinder head..    and  THIS  is   definitely   a   multi  torque and release   type  joint for  new hardware..     I may have    conjectured   this  with  the  cylinder head studs.

Link to comment
Share on other sites

I'm in the same boat as AH64ID called ARP and they said just to torque them once and they were good to go. I talked to turbolvr on the CF forum and he recommended the 3 torque process. 1st torque during install then 2nd loosen and retorque and 3rd at 1000 miles.  :2cents:

Link to comment
Share on other sites

Just because I am curious...anyone have a spec for the cummins head bolts meaning tensile strength.

Perhaps a comparison of them and the ARP studs. 

Its probabaly here already but I never word it the right way.

Chris

This is a Quote from a guy on CF About 12 valve bolts.

 

 

 

The stocks bolts are just under 11mm and about 150,000psi tensile strength. The 12mm 12.9 allen bolts are a full 12mm and and are about 170,000-180,000psi. Studs (not a specific brand) are a full 12mm and start at about 190,000 and go up from there.

The stock bolts are meant to be torqued to the plastic stage, and the stretch in the bolts is supposed to even out the force around the head. The studs and hi-strength bolts work on the principal that stronger is better.

Link to comment
Share on other sites

I do lots of race engines using head studs. I don’t understand the torque relax torque thing. What is important is heat cycles between torturing. On a race motor we torque the head studs, in equal steps, usually three steps. Heat cycle the motor, let it cool, re-torque, heat cycle the motor a couple more times, then re-torque one last time.

 

I am over kill with the three or four heat cycles. Most guys only do it once and never seem to have issues. I can’t see where a diesel would be any different. Studs aren’t that big a deal. Don’t over think it.

 

By the way, ARP studs have rolled threads, not cut threads. Take a close look at them and you will notice it. It is a good idea to chase the holes with a chaser tap just to make sure you remove anything that could be a contaminat. If you still have the head on the motor, don’t worry about it, go for it. Don't use a regular tap meant to cut threads, because it will. That opens the threaded hole up more and makes it sloppy. You can purchase a chaser tap on line at Summit or at most parts stores. Local tool stores should have them. A good item to have laying around in your box. After you use it, paint it red so you don't use it as a real tap. LOL

Link to comment
Share on other sites

×
×
  • Create New...