Jump to content
SAU Community

Rb25 Head Stud Thread Pitch/size

iruvyouskyrine

By iruvyouskyrine,
in General Maintenance

 Share

Recommended Posts

scotty nm35 Grand Master

scotty nm35

Posted
Posted

M11 standard i'm pretty sure (from ARP), no idea on the pitch though. I had to buy one for the VQ as they run the same M11 thread on the head bolts.

Make sure you get a bottoming tap.

GTRPSI Mentor

GTRPSI

Posted
Posted

To be more exact its actually M11 X 1.5 (pitch) for RB25's and RB30's.

RB26's are M12 X 1.5 pitch.

Reason i know is because im about to convert a RB30 block to RB26 head bolt sizes tomorrow for fun.

Make sure you get the bottoming out tap so yo can reach the end of the threaded hole if cleaning threads, the next one back is the plug tap and will be short 3-5 turns from the bottom, the starter tap will be 5-8 turns short.

GTRPSI Mentor

GTRPSI

Posted
Posted

Im waiting on 12mm CA625+ studs to arrive and a i have a set of 11mm studs but the box is sealed and i dont want to open it as im selling them.

A stock RB26 head bolt with washer fitted is 99.91mm long from under the washer head to the very end of the bolt including the threaded section that enters the block.

Remove the washer and from under the bolt head to the end of the threads its 102.72 mm.

Washer is 3.10mm thick exactly. (so im a few 0.00mm out somewhere)

Threaded section entering the block from the lengths above is around 27.5mm.

From there you will just need to add what you need to protrude out of the head to get the nut full on when working out stud lengths.

GTRPSI Mentor

GTRPSI

Posted
Posted

Do you have the length Pete? I want to compare to the VQ bolts I have here. (Not that I really want to go cutting L19's down, but I will if I have to. :P)

I was just down at Barrys and he gave me a set of RB26 ARP2000 stud kit to measure up as im still waiting for my studs to arrive.

Complete length of the whole stud is 124.37mm end to end.

Threaded section that enters the block is 23mm

74.27mm un-threaded shaft length.

Threaded section that nuts go on is 27.1mm.

So 23mm into block, 74.27mm shaft length, 27.1mm threaded for nuts and washer=124.37mm total length.

Hope that helps you. :)

scotty nm35 Grand Master

scotty nm35

Posted
Posted

The VQ bolt is 120mm from under the washer to the tip of the thread, so the length would be perfect, but it has an M11 x 1.25 pitch, so if the RB25/30 is 1.5mm pitch that won't work unfortunately.

GTRPSI Mentor

GTRPSI

Posted
Posted

Are you sure its 1.25 pitch into the block? It would provide real torque when tightening down.

Whats the final torque on them? A lot less than 100ft/lb?

ARP's studs for 25's and 26's are 1.5 pitch into the block but (i think) 1.25 on the heads nut face end. (Much finer)

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Yep, I was measuring the stock VQ25det head bolts, so it's the thread into the block. I can't remember the nm figures, but 76nm stock and 96nm for the L19's is stuck in my head for some reason, unless it was actually ft/lb figures.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      After market rear camber arm adjustment

      By Duncan · Posted

      Then, shorten them by 1cm, drop the car back down and have a visual look (or even better, use a spirit level across the wheel to see if you have less camber than before. You still want something like 1.5 for road use. Alternatively, if you have adjustable rear ride height (I assume you do if you have extreme camber wear), raise the suspension back to standard height until you can get it all aligned properly. Finally, keep in mind that wear on the inside of the tyre can be for incorrect toe, not just camber
    • V35Newbie
      After market rear camber arm adjustment

      By V35Newbie · Posted

      I know I have to get a wheel alignment but until then I just need to bring the rear tyres in a bit they're wearing to the belt on the inside and brand new on the outside edge. I did shorten the arms a bit but got it wrong now after a few klms the Slip and VDC lights come on. I'd just like to get it to a point where I can drive for another week or two before getting an alignment. I've had to pay a lot of other stuff recently so doing it myself is my only option 
    • Duncan
      After market rear camber arm adjustment

      By Duncan · Posted

      You just need a wheel alignment after, so just set them to the same as current and drive to the shop. As there are 2 upper links it may also be worth adding adjustable upper front links at the same time; these reduce bump steer when you move the camber (note that setting those correctly takes a lot longer as you have to recheck the camber at each length of the toe arm, through a range of movement, so you could just ignore that unless the handling becomes unpredictable)
    • V35Newbie
      After market rear camber arm adjustment

      By V35Newbie · Posted

      I got adjustable after market rear camber arm to replace the stock one's because got sick of having to buy new rear tyres every few months. Can anyone please let me know what the best adjustment length would be. I don't have the old ones anymore to get measurements. I'm guessing the stock measurement minus a few mm would do it. Please any help on replacing them would be fantastic I've watched the YouTube clips but no-one talks about how long to set the camber arm to.
    • GTSBoy
      Unpeeling the Orange

      By GTSBoy · Posted

      Heh. I copied the link to the video direct, instead of the thread I mentioned. But the video is the main value content anyway. Otherwise, yes, in Europe, surely you'd be expected to buy local. Being whichever flavour of Michelin, Continental or Pirelli suits your usage model.
×
×
  • Create New...