Jump to content
SAU Community

Recommended Posts

hi,

iv built a Rb30 bottom end with a RB26 head, RB26 head studs have a different diameter and RB30 head studs are two long..

what is the best option?

do you drill n tapp the block? or helicoil or what??

also timing belts...i think we are relocating the tentioner. what size do you need? iv read 152 teeth, but is this 100%? does anyone hav any info that could help me out?? this car has been off the road for a year now n im really keen on getting my engine it.. would be greatly appreciated

thanks

phone number: 0416 53 58 50 or reply

Link to comment
https://www.sau.com.au/forums/topic/236432-rb3026-head-studs-help-please/
Share on other sites

hi,

iv built a Rb30 bottom end with a RB26 head, RB26 head studs have a different diameter and RB30 head studs are two long..

what is the best option?

do you drill n tapp the block? or helicoil or what??

also timing belts...i think we are relocating the tentioner. what size do you need? iv read 152 teeth, but is this 100%? does anyone hav any info that could help me out?? this car has been off the road for a year now n im really keen on getting my engine it.. would be greatly appreciated

thanks

phone number: 0416 53 58 50 or reply

Drill and tap the block

Justjap in Sydney ( i think) keeps the belts in stock for RB 26/30 conversions. seen em advertized with other retailers aswell.

Drill and tap the block

Justjap in Sydney ( i think) keeps the belts in stock for RB 26/30 conversions. seen em advertized with other retailers aswell.

You can't drill and tap the block from 11mm to 12mm! The thread will never clean up. You can helicoil it. I'm not sure what others have done.

Cheers

Marty

You certainly can drill and tap the thread. You need to drill to 10.5mm, and drill the recess at the top of the hole to 12mm(this is vital) then tap the holes to M12 x 1.5. The new thread will follow the old thread. Another easier option (especially if the motor is assembled) is to use rb25 head studs, they are the correct thread for the rb30 block and the correct length for the rb26 head, you must ensure the 2 dowels are in though.

152 teeth is correct depending on the location of the second tensioner.

(low and high)

You certainly can drill and tap the thread. You need to drill to 10.5mm, and drill the recess at the top of the hole to 12mm(this is vital) then tap the holes to M12 x 1.5. The new thread will follow the old thread. Another easier option (especially if the motor is assembled) is to use rb25 head studs, they are the correct thread for the rb30 block and the correct length for the rb26 head, you must ensure the 2 dowels are in though.

I don't have a thread chart in front of me to check but I wouldn't have thought you could get the 11mm to clean up nicely to tap 12mm. As long as they chase the pitch correctly when tapping I guess you can do it. I would probably save the headache and use the RB25 head studs. That way it also stops the flimsy RB30 deck from warping when you try clamping down the 12mm studs to 85 foot pound.

Cheers

Marty

i personally wouldnt re-tap the thread for the bigger studs. i'd use rb25 studs. the more thickness u can leave in the block the better

as martin said. ~0.75mm isn't ideal to cut a new thread in, however that said ppl have re-cut them without any dramas.

  • 2 weeks later...
With over 40 x RB30's built since 1999, I would always use ARP (RB26) head studs.

Cheers

Gary

gary have you used a similar method as adriano has explained?? or can you recomend a different approach to the process

You 'could' tap the block to 12mm but from experience I can tell you it its perfectly fine to run 11mm RB25 head studs with a 26 head.

I've done alot of miles and drags with a best of 8.71 @ 162 with 11mm studs, over 1000hp, never had a problem.

Rob

  • Like 2

i use 1/2" arp head studs in my 26/30, my machiner actually got them from a US car i have to ask him again for the exact details, lucky as he deals with the old school muscle cars just as much as jap cars they were perfect length

ben...

i use 1/2" arp head studs in my 26/30, my machiner actually got them from a US car i have to ask him again for the exact details, lucky as he deals with the old school muscle cars just as much as jap cars they were perfect length

ben...

In our experience using 1/2 inch studs in the RB30 block cause the deck to distort when torqued as you need to be around 100 foot pound. The RB30 has a thinner deck than it's little brothers (RB25/26) and the largest size we have sucessfully seen is 12mm (slightly smaller than 1/2 inch). For ease of fitment the RB25 work fine.

Cheers

Marty

  • 2 months later...
  • 4 years later...

Can i please ask if anyone has ever had a drama with using rb25 arp head studs in a RB26/30.
And if you havent had any dramas what power and boost were you running with the 25studs.

Wish my builder told me about this before we got 3/4 through building the engine... im abit worried about running the rb25 head studs..

Only gna be running around 26psi or so through GT-SS with larger rear housings on e85 and higher com, type b poncams, ported etc etc..

Should be around the 400kw flat mark if im lucky....

But im kind of pissed off because i have ibeam rods and what not now i feel like the rb25 head studs is my weakest link ! :@
Now if i want to go a single or something in the future im gna feel like its just gna pop.

Can i please ask if anyone has ever had a drama with using rb25 arp head studs in a RB26/30.

And if you havent had any dramas what power and boost were you running with the 25studs.

Wish my builder told me about this before we got 3/4 through building the engine... im abit worried about running the rb25 head studs..

Only gna be running around 26psi or so through GT-SS with larger rear housings on e85 and higher com, type b poncams, ported etc etc..

Should be around the 400kw flat mark if im lucky....

But im kind of pissed off because i have ibeam rods and what not now i feel like the rb25 head studs is my weakest link ! :@

Now if i want to go a single or something in the future im gna feel like its just gna pop.

Read the post by rips a few up. I wouldn't worry at all about using rb25 head studs.

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



  • Similar Content

  • Latest Posts

    • I came here to note that is a zener diode too base on the info there. Based on that, I'd also be suspicious that replacing it, and it's likely to do the same. A lot of use cases will see it used as either voltage protection, or to create a cheap but relatively stable fixed voltage supply. That would mean it has seen more voltage than it should, and has gone into voltage melt down. If there is something else in the circuit dumping out higher than it should voltages, that needs to be found too. It's quite likely they're trying to use the Zener to limit the voltage that is hitting through to the transistor beside it, so what ever goes to the zener is likely a signal, and they're using the transistor in that circuit to amplify it. Especially as it seems they've also got a capacitor across the zener. Looks like there is meant to be something "noisy" to that zener, and what ever it was, had a melt down. Looking at that picture, it also looks like there's some solder joints that really need redoing, and it might be worth having the whole board properly inspected.  Unfortunately, without being able to stick a multimeter on it, and start tracing it all out, I'm pretty much at a loss now to help. I don't even believe I have a climate control board from an R33 around here to pull apart and see if any of the circuit appears similar to give some ideas.
    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
×
×
  • Create New...