Jump to content
SAU Community

Recommended Posts

Hi Guys,

My open deck RB26 project is coming along nicely, however I am still trying to locate a good option for the head studs or bolts to hold it all together.

The engine has an additional height of about 2mm, so the studs need to be 150mm long approximatly... The closest I have found from another engine is 149mm, which is probably going to do the job fine, but these bolts are $35USD each so Im looking for another option.

Im considering having the block drilled and helicoiled so I can use alternative head studs or bolts with imperial threads, as that opens up the world of chev and ford studs as being a possability.

Does anyone who's done this kind if build in the past have a suggestion?

Cheers,

Ian

Link to comment
https://www.sau.com.au/forums/topic/273051-head-studs-for-an-open-deck-engine/
Share on other sites

id go to a stud, that way you could just use the std arp rb26 headstud kit as i dont think the 2mm is going to make any difference as theres plenty of thread for the nut to screw down onto.

id go to a stud, that way you could just use the std arp rb26 headstud kit as i dont think the 2mm is going to make any difference as theres plenty of thread for the nut to screw down onto.

Are you saying the RB26 ARP studs are 20mm longer than they need to be? I havnt got a set handy to compare to a standard head bolt for thread penetration depth into the block...

Edited by GTRNUR
Are you saying the RB26 ARP studs are 20mm longer than they need to be? I havnt got a set handy to compare to a standard head bolt for thread penetration depth into the block...

Must have been a typo Ian, Your original post said "2ml" longer

I would use 1/2in studs, im pretty sure they fit the head without modification.

The only problem is with the head locator dowels that are 13.1mm in diameter. If I go to 1/2" studs it means adding dowels elsewhere to positively locate the head. Ive yet to find out what people do when running 1/2" studs in the RB engines.... I did read somewhere that on RB30's the 100ft-lb torque that the 1/2" studs need to get the right bolt stretch causes the top of the deck to distort a little so the head gasket probably wont seal too well witht that...

If that is a problem for a block thats got flanged sleeves in it though is anyone's guess.

The only problem is with the head locator dowels that are 13.1mm in diameter. If I go to 1/2" studs it means adding dowels elsewhere to positively locate the head. Ive yet to find out what people do when running 1/2" studs in the RB engines.... I did read somewhere that on RB30's the 100ft-lb torque that the 1/2" studs need to get the right bolt stretch causes the top of the deck to distort a little so the head gasket probably wont seal too well witht that...

If that is a problem for a block thats got flanged sleeves in it though is anyone's guess.

I think Dirtgarage uses 1/2" studs on Twoogle?

Hope the build is going well.

20mm makes it a problem with the arp rb26 studs :laugh:. i just measured it then, with the arp rb26 studs, theres 13mm from the top of the nut to the top of the stud with it torqued to arp specs

what you will have to do is either fill out an order form, or ring arp direct and order a set of studs similar to the rb26 kit but with 20mm more shank. shouldnt be too much more expensive then a normal arp set.

pic is of rb26 headbolt and arp2000 headstud

P.S got pics of said spacer/hi deck setup?

post-20917-1244020891_thumb.jpg

I think Dirtgarage uses 1/2" studs on Twoogle?

Hope the build is going well.

Yes im making good headway with the project.

The crankshaft modifications are finished and its now drilled, screwed and balanced and has an 87mm stroke. The Rb26 block was bored out to 92mm today and I believe some if not all of the sleeves were pressed in today too. Ive had the oil galleries drilled and grub screwed too. I am still waiting on the custom order CP pistons and a nismo twin plate to arrive so I can have the bottom end balance finished, and I also need the pistons so the sleeves can be bored to match etc. Ive gone for 87mm pistons for this prototype engine.

The spacer plate fabriaction has been an excercise and a half. Got it right on the 4th attempt. The waterjet cutters had a tooling problem that caused the trial template I had cut from thing material to be inaccurate. The 3 plates I then had cut from 20mm plate after that were all useless. They then replaced their cutting nossels and the 4th cut came up perfect.

I'll be posting up the build when ive got everything back in my workshop. Hope to have it in a car and running and tuned in 2-3 months max.

Thanks for the pics of the bolts too Shane. Interesting the little ridge at the edge of the 12x1.5 thread on the block end of the stud, and looks like 12x1.25 at the other end right?

my verniers are saying its an M11 thread both ends. The block end is definately metric, but im unsure on what thread arp use on their nuts, as u said its obviously finer.

Not sure whats doing with the ridge, cant say ive taken notice whilst installing them so cant say if it stops them bototming out or what. Also the shank is smaller than the threaded ends.

speak to willall (sa) or racepace (vic) as both have extensive experience with open deck rb26's.

I may be interested in some spacer plates as we have the sleeving process fully sorted now. if your looking to sell some feel free to pm me.

Edited by URAS
speak to willall (sa) or racepace (vic) as both have extensive experience with open deck rb26's.

Yeah but its a fine line to cross asking these guys to share the knowledge freely that they use to build their top level engines... If they were willing to volunteer the informaiton freely I'd really appreciate it, but I understand completely why they'd hold most of their cards for an open deck engine close to their chests. After all its their livelyhood.

Also i'd wager they are just using ARP anyway. I was hoping for an alternative and dont need the strength nor the expensive of ARP. Im not building some 700+hp monster. The engine will probably end up with a pair of GTRS's on it and not reving past 7500. 500awhp would be plenty. Its built for torque and low to mid range response.

Yeah but its a fine line to cross asking these guys to share the knowledge freely that they use to build their top level engines... If they were willing to volunteer the informaiton freely I'd really appreciate it, but I understand completely why they'd hold most of their cards for an open deck engine close to their chests. After all its their livelyhood.

Also i'd wager they are just using ARP anyway. I was hoping for an alternative and dont need the strength nor the expensive of ARP. Im not building some 700+hp monster. The engine will probably end up with a pair of GTRS's on it and not reving past 7500. 500awhp would be plenty. Its built for torque and low to mid range response.

ah sorry yeah i thought you were after ARP's.... i will look at some TB45 and TB48 head studs for you as i remmebr them being longer... i have a few laying about from turbo dirt dweller builds.

Do you have a solution for sealing the deck and plate? dont need to post as i also understand...just interested.

ah sorry yeah i thought you were after ARP's.... i will look at some TB45 and TB48 head studs for you as i remmebr them being longer... i have a few laying about from turbo dirt dweller builds.

Do you have a solution for sealing the deck and plate? dont need to post as i also understand...just interested.

I kept that really simple. A standard RB26 or RB30E head gasket with the center cut out of it to clear the sleeves will do the job, sprayed with some hylomar. I considered making up a copper gasket cut but frakly the price of copper is crazy and using a propper gasket is a cheaper and probably a better option.

The spacer plate can be bolted to the block with a set of 50mm allen head bolts and torqued to spec with a gasket installed when the block is decked. The other option was to mathmatically work it out and set the sleeve height to be about 3 thou higher than the spacer plate and spacer plate gasket to get a better cylinder-head seal. This is one of dartron's tricks with how they recommend setting up sleeved block top ends.

Im keen to see how long the TB45/48 bolts are. Shame there arent many of those engine around dead to pull apart and check out. I figured they'd be built like a diesal though being that the blocks are milspec rated.

Well it looks like i'll be using porsche 928 head studs in this first build. They are certainly up to the task.

Also, for those that were interested I have attached a few pics of the machined engine block. The sleeves still need to be bored out to match the pistons that should be arriving in 3-4 weeks, which isnt a bad thing.. because Ive decided to change the bottom end of the engine a little. Im changing the crank modifications a little and getting a set of pauter x beam rods for it.

Considering this prototype is going in the R34 I want it strong as hell. The x beams should make the bottom end capable of supporting 700hp easy. Im not running an ARP main stud kit in this engine, which is really the only limitation as to why it wouldnt reliably handle more power. Power isnt what this is about anyway, its about response, mid range torque and reliablity.

post-26553-1244517716_thumb.jpg

post-26553-1244517744_thumb.jpg

post-26553-1244517761_thumb.jpg

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 did end up getting it sorted, as GTSBoy said, there was a corroded connection and wire that needed to be replaced. I ended up taking out the light assembly, giving everything a good clean and re-soldered the old joints, and it came out good.
    • Wow, thanks for your help guys 🙏. I really appreciate it. Thanks @Rezz, if i fail finding any new or used, full or partial set of original Stage carpets i will come back to you for sure 😉 Explenation is right there, i just missed it 🤦‍♂️. Thanks for pointing out. @soviet_merlin in the meantime, I received a reply from nengun, and i quote: "Thanks for your message and interest in Nengun. KG4900 is for the full set of floor mats, while KG4911 is only the Driver's Floor Mat. FR, RH means Front Right Hand Side. All the Full Set options are now discontinued. However, the Driver's Floor Mat options are still available according to the latest information available to us. We do not know what the differences would be, but if you only want the one mat, we can certainly see what we can find out for you". Interesting. It seems they still have some "new old stock" that Duncan mentioned 🤔. I wonder if they can provide any photos......And i also just realized that amayama have G4900 sets. I'm tempted too. 
    • Any update on this one? did you manage to get it fixed?    i'm having the same issue with my r34 and i believe its to do with the smart entry (keyless) control module but cant be sure without forking out to get a replacement  
    • So this being my first contribution to the SAU forums, I'd like to present and show how I had to solve probably one of the most annoying fixes on any car I've owned: replacing a speedometer (or "speedo") sensor on my newly acquired Series 1 Stagea 260RS Autech Version. I'm simply documenting how I went about to fix this issue, and as I understand it is relatively rare to happen to this generation of cars, it is a gigantic PITA so I hope this helps serve as reference to anyone else who may encounter this issue. NOTE: Although I say this is meant for the 260RS, because the gearbox/drivetrain is shared with the R33 GTR with the 5-speed manual, the application should be exactly the same. Background So after driving my new-to-me Stagea for about 1500km, one night while driving home the speedometer and odometer suddenly stopped working. No clunking noise, no indication something was broken, the speedometer would just stop reading anything and the odometer stopped going up. This is a huge worry for me, because my car is relatively low mileage (only 45k km when purchased) so although I plan to own the car for a long time, a mismatched odometer reading would be hugely detrimental to resale should the day come to sell the car. Thankfully this only occurred a mile or two from home so it wasn't extremely significant. Also, the OCD part of me would be extremely irked if the numbers that showed on my dash doesn't match the actual ageing of the car. Diagnosing I had been in communication with the well renown GTR shop in the USA, U.P.garage up near University Point in Washington state. After some back and forth they said it could be one of two things: 1) The speedometer sensor that goes into the transfer case is broken 2) The actual cluster has a component that went kaput. They said this is common in older Nissan gauge clusters and that would indicate a rebuild is necessary. As I tried to figure out if it was problem #1, I resolved problem #2 by sending my cluster over to Relentless Motorsports in Dallas, TX, whom is local to me and does cluster and ECU rebuilds. He is a one man operation who meticulously replaces every chip, resistor, capacitor, and electronic component on the PCB's on a wide variety of classic and modern cars. His specialty is Lexus and Toyota, but he came highly recommended by Erik of U.P.garage since he does the rebuilds for them on GTR clusters.  For those that don't know, on R32 and R33 GTR gearboxes, the speedometer sensor is mounted in the transfer case and is purely an analog mini "generator" (opposite of an alternator essentially). Based on the speed the sensor spins it generates an AC sine wave voltage up to 5V, and sends that via two wires up to the cluster which then interprets it via the speedometer dial. The signal does NOT go to the ECU first, the wiring goes to the cluster first then the ECU after (or so I'm told).  Problems/Roadblocks I first removed the part from the car on the underside of the transfer case (drain your transfer case fluid/ATF first, guess who found out that the hard way?), and noted the transfer case fluid was EXTREMELY black, most likely never changed on my car. When attempting to turn the gears it felt extremely gritty, as if something was binding the shaft from rotating properly. I got absolutely no voltage reading out of the sensor no matter how fast I turned the shaft. After having to reflow the solder on my AFM sensors based on another SAU guide here, I attempted to disassemble the silicone seal on the back of the sensor to see what happened inside the sensor; turns out, it basically disintegrated itself. Wonderful. Not only had the electrical components destroyed themselves, the magnetic portion on what I thought was on the shaft also chipped and was broken. Solution So solution: find a spare part right? Wrong. Nissan has long discontinued the proper sensor part number 32702-21U19, and it is no longer obtainable either through Nissan NSA or Nissan Japan. I was SOL without proper speed or mileage readings unless I figured out a way to replace this sensor. After tons of Googling and searching on SAU, I found that there IS however a sensor that looks almost exactly like the R33/260RS one: a sensor meant for the R33/R34 GTT and GTS-T with the 5 speed manual. The part number was 25010-21U00, and the body, plug, and shaft all looked exactly the same. The gear was different at the end, but knowing the sensor's gear is held on with a circlip, I figured I could just order the part and swap the gears. Cue me ordering a new part from JustJap down in Kirrawee, NSW, then waiting almost 3 weeks for shipping and customs clearing. The part finally arrives and what did I find? The freaking shaft lengths don't match. $&%* I discussed with Erik how to proceed, and figuring that I basically destroyed the sensor trying to get the shaft out of the damaged sensor from my car. we deemed it too dangerous to try and attempt to swap shafts to the correct length. I had to find a local CNC machinist to help me cut and notch down the shaft. After tons of frantic calling on a Friday afternoon, I managed to get hold of someone and he said he'd be able to do it over half a week. I sent him photos and had him take measurements to match not only the correct length and notch fitment, but also a groove to machine out to hold the retentive circlip. And the end result? *chef's kiss* Perfect. Since I didn't have pliers with me when I picked up the items, I tested the old gear and circlip on. Perfect fit. After that it was simply swapping out the plug bracket to the new sensor, mount it on the transfer case, refill with ATF/Nissan Matic Fluid D, then test out function. Thankfully with the rebuilt cluster and the new sensor, both the speedometer and odometer and now working properly!   And there you have it. About 5-6 weeks of headaches wrapped up in a 15 minute photo essay. As I was told it is rare for sensors of this generation to die so dramatically, but you never know what could go wrong with a 25+ year old car. I HOPE that no one else has to go through this problem like I did, so with my take on a solution I hope it helps others who may encounter this issue in the future. For the TL;DR: 1) Sensor breaks. 2) Find a replacement GTT/GTS-T sensor. 3) Find a CNC machinist to have you cut it down to proper specs. 4) Reinstall then pray to the JDM gods.   Hope this guide/story helps anyone else encountering this problem!
    • So this being my first contribution to the SAU forums, I'd like to present and show how I had to solve probably one of the most annoying fixes on any car I've owned: replacing a speedometer (or "speedo") sensor on my newly acquired Series 1 Stagea 260RS Autech Version. I'm simply documenting how I went about to fix this issue, and as I understand it is relatively rare to happen to this generation of cars, it is a gigantic PITA so I hope this helps serve as reference to anyone else who may encounter this issue. NOTE: Although I say this is meant for the 260RS, because the gearbox/drivetrain is shared with the R33 GTR with the 5-speed manual, the application should be exactly the same. Background So after driving my new-to-me Stagea for about 1500km, one night while driving home the speedometer and odometer suddenly stopped working. No clunking noise, no indication something was broken, the speedometer would just stop reading anything and the odometer stopped going up. This is a huge worry for me, because my car is relatively low mileage (only 45k km when purchased) so although I plan to own the car for a long time, a mismatched odometer reading would be hugely detrimental to resale should the day come to sell the car. Thankfully this only occurred a mile or two from home so it wasn't extremely significant. Also, the OCD part of me would be extremely irked if the numbers that showed on my dash doesn't match the actual ageing of the car. Diagnosing I had been in communication with the well renown GTR shop in the USA, U.P.garage up near University Point in Washington state. After some back and forth they said it could be one of two things: 1) The speedometer sensor that goes into the transfer case is broken 2) The actual cluster has a component that went kaput. They said this is common in older Nissan gauge clusters and that would indicate a rebuild is necessary. As I tried to figure out if it was problem #1, I resolved problem #2 by sending my cluster over to Relentless Motorsports in Dallas, TX, whom is local to me and does cluster and ECU rebuilds. He is a one man operation who meticulously replaces every chip, resistor, capacitor, and electronic component on the PCB's on a wide variety of classic and modern cars. His specialty is Lexus and Toyota, but he came highly recommended by Erik of U.P.garage since he does the rebuilds for them on GTR clusters.  For those that don't know, on R32 and R33 GTR gearboxes, the speedometer sensor is mounted in the transfer case and is purely an analog mini "generator" (opposite of an alternator essentially). Based on the speed the sensor spins it generates an AC sine wave voltage up to 5V, and sends that via two wires up to the cluster which then interprets it via the speedometer dial. The signal does NOT go to the ECU first, the wiring goes to the cluster first then the ECU after (or so I'm told).  Problems/Roadblocks I first removed the part from the car on the underside of the transfer case (drain your transfer case fluid/ATF first, guess who found out that the hard way?), and noted the transfer case fluid was EXTREMELY black, most likely never changed on my car. When attempting to turn the gears it felt extremely gritty, as if shttps://imgur.com/6TQCG3xomething was binding the shaft from rotating properly. After having to reflow the solder on my AFM sensors based on another SAU guide here, I attempted to disassemble the silicone seal on the back of the sensor to see what happened inside the sensor; turns out, it basically disintegrated itself. Wonderful. Not only had the electrical components destroyed themselves, the magnetic portion on what I thought was on the shaft also chipped and was broken. Solution So solution: find a spare part right? Wrong. Nissan has long discontinued the proper sensor part number 32702-21U19, and it is no longer obtainable either through Nissan NSA or Nissan Japan. I was SOL without proper speed or mileage readings unless I figured out a way to replace this sensor. After tons of Googling and searching on SAU, I found that there IS however a sensor that looks almost exactly like the R33/260RS one: a sensor meant for the R33/R34 GTT and GTS-T with the 5 speed manual. The part number was 25010-21U00, and the body, plug, and shaft all looked exactly the same. The gear was different at the end, but knowing the sensor's gear is held on with a circlip, I figured I could just order the part and swap the gears. Cue me ordering a new part from JustJap down in Kirrawee, NSW, then waiting almost 3 weeks for shipping and customs clearing. The part finally arrives and what did I find? The freaking shaft lengths don't match. $&%* I discussed with Erik how to proceed, and figuring that I basically destroyed the sensor trying to get the shaft out of the damaged sensor from my car. we deemed it too dangerous to try and attempt to swap shafts to the correct length. I had to find a local CNC machinist to help me cut and notch down the shaft. After tons of frantic calling on a Friday afternoon, I managed to get hold of someone and he said he'd be able to do it over half a week. I sent him photos and had him take measurements to match not only the correct length and notch fitment, but also a groove to machine out to hold the retentive circlip. And the end result? *chef's kiss* Perfect. Since I didn't have pliers with me when I picked up the items, I tested the old gear and circlip on. Perfect fit. After that it was simply swapping out the plug bracket to the new sensor, mount it on the transfer case, refill with ATF/Nissan Matic Fluid D, then test out function. Thankfully with the rebuilt cluster and the new sensor, both the speedometer and odometer and now working properly!   And there you have it. About 5-6 weeks of headaches wrapped up in a 15 minute photo essay. As I was told it is rare for sensors of this generation to die so dramatically, but you never know what could go wrong with a 25+ year old car. I HOPE that no one else has to go through this problem like I did, so with my take on a solution I hope it helps others who may encounter this issue in the future. For the TL;DR: 1) Sensor breaks. 2) Find a replacement GTT/GTS-T sensor. 3) Find a CNC machinist to have you cut it down to proper specs. 4) Reinstall then pray to the JDM gods.   Hope this guide/story helps anyone else encountering this problem!
×
×
  • Create New...