Arp Main Studs Rb26

[OMGGTR]

Hi guys im in the process of finishing my bottom end but ive stuffed up and thank god i relised now rather than later, i did my studs up with loctite and tensioned them not thinking at all that thieir supposed to be finger tight with the arp lube, the question is what torque do the rb26 nuts for arp maines need to be ??? And the 3 longer studs what iis the key to them? Do i need to trim them and why if so!?

[The Dan]

The torque ARP specify is 70 ft/lbs but you will probably find that the tunnel will become small by about .0002 so we suggest only torquing them to 60 ft/lbs as it still meets the stretch requirements they specify but doesn't pull the tunnel out of round. It doesn't happen all the time but enough times to matter

[OMGGTR]

Ok u saved my day whenever u need info people act dum and hide lol thanks alot any chance u kno about trimming the 3 longer studs??

[The Dan]

As for trimming, you should only need to trim the one that sits under the driveshaft tube. Yes you will need to otherwise the sump won't go on if you are still using 4wd.

It is ok to cut it but do so carefully with a grinder (very thin blade and make sure you cut it slowly so as to not introduce much heat into the stud). Clean the thread in the block with a tap to make sure it is easy to remove and refit or with your grinder cut a slit in the top so you can use a screw driver to install the stud

[The Dan]

Ok u saved my day whenever u need info people act dum and hide lol thanks alot any chance u kno about trimming the 3 longer studs??

Yes, we have had SOME of the back ones foul in the lump in the back of the sump so either relieve the sump or remove about 2-3mm from the back 2 as well and yeah, the middle one is explained above

[Gerg_R31]

Just to add if you got 3 longer studs then that probably the Rb25/30 kit only difference, and you really should have it line honed to recorrect the roundness but elite racing has said everything i would have

and with the locktite id recommend to run a tap through the threads to clean out excess lock tite

[camandcandice]

When I built my rb26 I drilled the threads out deeper so the studs sit lower to give Clearence between the sump and studs rather then hacking the studs, The studs won't bottom out there is 10mm plus before you hit the bottom.

Cheers cam

[OMGGTR]

Did the job today was a headache because ive already installed 4 pistons so i could not take the crank out studs were terrible to get out persisted tho cleaned up everything as best i could and all went bak in nuts went in to 60 ft lb give or take .5 calibration on my torqueangle

[Gerg_R31]

Good stuff, keep us updated

[r33_racer]

When I built my rb26 I drilled the threads out deeper so the studs sit lower to give Clearence between the sump and studs rather then hacking the studs, The studs won't bottom out there is 10mm plus before you hit the bottom.

Cheers cam

Bingo! Thats the ideal way.

[Gerg_R31]

But not ideal way to do it in a back yard

[r33_racer]

But not ideal way to do it in a back yard

nothing is ideal in the backyard lol.

[T04GTR]

do up as per arp specs, then get tunnel bored. if not then just use the factory bolts.

[ahh 33 s2]

i didnt cut the back studs and i cracked my sump as there was no info about the back studs that i had read, i new about the middle for the drive shaft but wasnt running 4wd so didnt have to bother with that,

[OMGGTR]

Can i use standard torque on the cap bolts ? Their arp and eagle rods sorry but i got no info with my parts

[zebra]

why dont you ring arp and find out

[The Dan]

When I built my rb26 I drilled the threads out deeper so the studs sit lower to give Clearence between the sump and studs rather then hacking the studs, The studs won't bottom out there is 10mm plus before you hit the bottom.

Cheers cam

Firstly its not hacking the studs. This procedure was actually recommended by ARP themselves when I called them about it. Yes I did ring America and yes I am that pedantic about my engines. Drilling is possible but risk of damage to existing thread is high so it is actually the LAST thing you should attempt and certainly not for someone who lacks the experience to carry the job out correctly

Bingo! Thats the ideal way.

As above, ONLY capable people should do it this way and even then, there is a reason Nissan didn't make the thread go deeper. The oil feed gallery actually runs within 5mm of the base of that hole on one side. Drill too deep and you bust into the oil gallery. Sure this may not be an issue because the bolt will cover the hole anyway but what if you drill through and a tiny bit of swarf hangs on? Just needs a small amount of oil to wash it through of maybe some engine vibration or whatever. I don't think it is the ideal way but if you really know what you are doing, you still need to be extremely careful

do up as per arp specs, then get tunnel bored. if not then just use the factory bolts.

Also not a good idea. There are nowhere near enough competent engineers who can accurately tunnel bore a straight 6 block. The fact is it doesn't need to be tunnel bored, none of the engines I have built have ever needed to be tunnel bored. The torque specified by ARP is not specified because they know the exact torque they want, its because they want a certain amount of stretch in the bolt so that the bolt load is correct. We have checked bolt stretch at the 60ft/lb mark and the stretch is still within ARP specs and also confirmed by them to the point where they are considering changing their instructions based on our findings and the fact they also agree tunnel boring is not ideal

Can i use standard torque on the cap bolts ? Their arp and eagle rods sorry but i got no info with my parts

You should find that Eagle rods will be 44-45ft/lbs (they used to be 44 but changed to 45 later). You can actually find the information on their website if you don't have the spec sheet with you.

[The Dan]

They may need to be 40 or 43ft/lbs. Check the link below and confirm which bolt you have

I haven't used an Eagle in a while so they may have changed them

They do not use standard off the shelf ARP bolts so don't go off ARP's recommendation and DO NOT only do them down to 50 Nm as the standard ones are

http://www.eaglerod.com/index.php?option=com_content&task=view&id=24&Itemid=25

[OMGGTR]

Cheers found a info sheet hiding lol 43 ft lbs

[T04GTR]

dan,

cool. i have measured just over 1 thou out of round with the studs. some are worse than others. and some dont deform. simply doing the bolts up to less than specified is scary. out of curiosity how did you measure the stud stretch? in a jig of some sorts?

each engine is differant. if it is out of round it will ware badly.

arp studs are a torque to yield fastner and are designed to stretch an amount. the wrong preload is very bad. as for rod bolts for crist sake. just get someone with half an idea to build you a motor before it falls apart.

you must have some pretty rubbish machinests up there if they cant tunnel bore a cast iron 6 cyl.

IF IN DOUT, FOLLOW THE ARP MANUAL. not a "itl be good mate"