Jump to content
SAU Community

My Rb25-30 Build

joe blo

By joe blo,
in Engines & Forced Induction

 Share

Recommended Posts

joe blo Experienced

joe blo

Posted
Posted (edited)

hi guys. just about to put the head on my rebuilt rb30 bottomend. still unsure of a few things so i made this thread to get the info i need.tandard computer be able to run it while i run it in coz i dont have any money to tune my aftermarket ecu and injectors anymore so hopefully i can run it in on the standard one coz i just wanna get it going. it wont run too rich and cause the rings not to bed in will it?

1. im doing a rb25 head on rb30 bottomend with rb25 headbolts and a genuine nissan headgasket. what are the torque settings and stages and tightening order and process for the headbolts?

2. what oil restrictors should i get or will the standard ones in the rb30 be ok? i have a spool rear head oil drain kit to go on it also.

3. with the power steering bit that doesnt go on properly or something does it need to be modified on the block or on the powersteering bracket? i think ive read that some of them will go straight on without modifying it, think it is the block actually. if i put up a pic can someone tell me if mine will beed to be modified? will get one later if needed.

4. what sump do i use to go into my r33 gtst? rb25 or rb30?

5. do i use all the rb25 powersteering and harmonic balancer and anything else and use new rb25 belts except the timing belt?

6. if i do the engine lowering method by slotting the engine mounts can i use the current dump pipe and exhaust and everything and it will all work properly?

7. will the gearbox and tailshaft still be aligned properly after lowering the motor?

that should do for now. been doing this for ages and always get stuck and dont worry about finishing it so i made this so i can get it done.

Edited by joe blo
Link to comment
https://www.sau.com.au/forums/topic/310857-my-rb25-30-build/
Share on other sites
brother_david Rising Star

brother_david

Posted
Posted (edited)

1. The ARP bolts should be tensioned to 108.5 NM, all done i three steps, i.e. 35, 80 and 108.5

-You might also want to loosen them up to 3 times before started for the first time, to get perfect tension across the head, thats what we do on our builds. Also it is recommended to do this atleast once after you have driven the car for acouple of weeks, aluminium is a living material.

2. What oilpump are you using?

3. It said to be needed to grind a small piece of the block..

4. Im using a RB30 sump, no problem with clearance!

5. Yes.

6. Probably not, the engine is 38mm taller and it wont come down that much before the sump hits the crossmember, BUT im not sure!

7. Wouldnt that be the reason for lowering the engine :D Actually, a known construction fact is that alittle angle is needed to get the correct tension on parts but its abit much if you dont change the mounts :D

Hope that helps, i might be wrong on some part but i think i've covered the morepart of it!

/Dave

Edited by brother_david
joe blo Experienced

joe blo

Posted
  • Author
Posted (edited)
1. The ARP bolts should be tensioned to 108.5 NM, all done i three steps, i.e. 35, 80 and 108.5

-You might also want to loosen them up to 3 times before started for the first time, to get perfect tension across the head, thats what we do on our builds. Also it is recommended to do this atleast once after you have driven the car for acouple of weeks, aluminium is a living material.

im using nissan headbolts. will they be the same as arp ones? or would i just tension it same as if im putting the rb25 head on a rb25 block?

2. What oilpump are you using?

il be using rb25det oil pump with crank collar fitted on crank

6. Probably not, the engine is 38mm taller and it wont come down that much before the sump hits the crossmember, BUT im not sure!

7. Wouldnt that be the reason for lowering the engine :D Actually, a known construction fact is that alittle angle is needed to get the correct tension on parts but its abit much if you dont change the mounts :D

i thought you lowered the engine so it doesnt hit the bonnet because of the extra height

Hope that helps, i might be wrong on some part but i think i've covered the morepart of it!

/Dave

Edited by joe blo
brother_david Rising Star

brother_david

Posted
Posted

1. Since its a RB25 head, and RB25 bolts and the 'weakest' part of the bolt is the nut, since the bolt has got more threads holding it down in the block, i would go for the RB25-RB25 settings.

2. Ill recommend 1.5mm front and rear, might even think of blocking the rear one, popular to do to get right oil pressure but thats more on RB26 heads that only have one oil channel to the head. Take a search in the RB30 conversion-thread, dont remember the details but its in there somewhere, just search for restrictors. Good thing you got the oil crank collar.

7. Yea sorry about that mate, ofcourse you would want to get it as low as needed to close the bonnet but still keep in mind the clearance between the sump and crossmember :D

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

    • Sean'O
      3D printing fun

      By Sean'O · Posted

      No worries at all 🫡 I think the most satisfying things to make are the little bits that are just impossible to find or they're no longer manufactured. Generally I always try to replace parts with OEM wherever possible. This little project is also great because it'll never see the light of day, but strengthen these brackets so it's not just relying on the little standard screws in the headlight plastic. As soon as I saw the standard brackets and screws I thought, "well I'm not going to install with just the screws, the plastic tabs will just snap off". It's crazy how expensive everything has become yeah. But I suppose that's supply and demand; granted it's a lot easier to get brand new genuine parts these days which is fantastic 😊, I don't have to get totally reamed at the local Nissan dealer ha ha We sure are lucky we have all these manufacturers making parts these days, a few really great Australian companies too like Platinum Racing Products and Fit Mint Automotive, what a time to be alive ❤️ . I've got my eye on the RB26 head by PRP as mine has a very fine hairline crack, so that'll need to be addressed some time in the future. If you have any requests or odd things to make feel free to let me know and I can have a crack at making replacement parts ✌️
    • Duncan
      3D printing fun

      By Duncan · Posted

      Thanks for sharing this, and BTW if your headlights are in good condition they are worth thousands....you might want to consider replacing them with brand new LED ones like this (https://www.nengun.com/78works/full-led-headlights-r32-skyline) and making enough profit to buy a house in Sydney
    • Duncan
      R32 GTS (RB20DE) clogged cat

      By Duncan · Posted

      I'm not sure what sort of shops are nearby, but I'd expect any reasonable exhaust shop could put a cat in it that will not restrict the power that engine makes. Otherwise, if you want to remove it, short lengths that replace the cat are readily available online, search for "de-cat pipes" or "test pipes"  
    • Sean'O
      3D printing fun

      By Sean'O · Posted

      Howdy friends, So another weird one today, I was looking into replacing some broken clips holding the front grille for the R32 GTR (part number 01553-03831), and noticed the brackets which are supposed to hold the grille in place were also missing 😑. I do recall seeing this issue many years ago, but didn't fix it at the time. A quick look on eBay and I was able to find the genuine brackets, along with all the screws which suited the headlights (part numbers 26042-08U05,26092-08U05). Happy days!....  Once they arrived however there was an extra nut in the packaging which implied that there should also be a bolt or a stud, and sure enough, after a bit of searching I found this thread from 2013, and @Ants clearly shows a stud should be present. Reading around a bit more, it's possible the headlights on my car are the "povo pack" headlights as mentioned by @funkymonkey in this thread way back in 2008. This could explain why the studs are missing on my set of headlights. Looking at the headlight diagram I wasn't able to see a suitable part number for the stud itself. The headlight did indeed have a recess that looked like it would accept a stud, but interestingly no thread or anything obvious how the stud would be affixed to the headlight, I suspect it may have been glued in, press fit, or melted into the plastic at the factory. Another member may be able to clarify if they happen to have a genuine set of N1 headlamps. The only thing we have to work with within the recess is a keyway which likely is there to prevent the stud from rotating within the recess. In any case, back to 3D printing, I put together a model which acts like a pug with a friction fit inside this recess, making use of the keyway so it doesn't rotate while tightening a bolt. Printing in TPU will allow it to slightly swell making a nice snug fit without cracking the part. I've designed the adaptor it to accept an 20 mm M6 bolt (stainless with a cap head in my case), as opposed to the standard M5 stud and I made use of the standard galvanised split washer that came with the genuine brackets from Nissan. Once the bolt and screws were all in place, giving the bracket a gentle shake gave the classic "shaking the car" feeling, very solid, which gives me confidence this is going to be able to hold on much better than the janky solution which seems to have been here for the past decade or so. Overall I'm really pleased with how this turned out and maybe there are more people out there running these headlights without a centre stud at all! Link to the freely available model on Printables: Click here Regards, Sean  
    • GabsReDeal
      R32 GTS (RB20DE) clogged cat

      By GabsReDeal · Posted

      Hey everyone, This is my first post apart of the introduction. I tried searching a bit on the forum but couldn't really get a straight answer. I got the car to my mechanic as I felt it being weak. It seems that it was missing on two cylinders due to the injectors. I had all my injectors clean and the car runs much better. The mechanic also confirmed my suspicions that the cat is clogged and needs to be tackled asap. The cat rattles a bit and the hot exhaust warning frequently lights up when driving after getting the injectors clean. In my introduction I was asked about what modification I might be interested in and mentioned a cat delete. From what I was told, this is not really beneficial on the RB20DE and there are more cons than pros.  Could perhaps anyone give some suggestions on what the best course of action would be since the current cat is toast and needs to be removed/replaced anyway? I can also sometimes smell a strong smell of fuel, but I'm not sure if this is related.
×
×
  • Create New...