Jump to content
SAU Community

Fixing A Rb30 Bottom End On The Cheap

unique1

By unique1,
in Engines & Forced Induction

 Share

Recommended Posts

unique1 Mentor

unique1

Posted
Posted (edited)

hey guys i got hold of a rb30 bottom end today (i have the rb26 head ready to go) and i didnt plan on pulling it down to be honest, but it didnt have the water feed for the turbo tapped (though its got the turbo oil feed tapped and the machined front for the tensioner) so i thought i better strip it and give it a clean up. This motor is for throwing in a stripped out track car and having some cheap fun, if it blows up i dont care ill buy another bottom end, so cheap is the aim of the game incase it does let go and i dont want too much invested in the bottom end :ermm:

1. The core plugs on the block are all brand new except the rear one behind the auto flywheel so i need a core plug for that, the crank seals have looked to have eaten into the crank a tiny bit as well, is this a big problem or only if its eaten into it a real lot? how do u fix that if its an issue, and how can i tell if its too bad or not?

2. The big end bearings looked fairly good and are standard NDC ones, i think i wont bother changing these at all, and the main bearings are ACL std size as well which look good too so ill be leaving them as well.

3. Now i have a hks 1.2mm drag metal head gasket lying around from my other 26 motor builds and wouldnt mind using that instead of buying a new stock gasket, but do u think to use a metal gasket i need to get the block decked to make sure its flat? how much can u deck the 30 block before piston to valve clearance becomes an issue? whats a cheap rb26 gasket worth?

4. i also have to tap the head bolt holes for the rb26 bolts, is this possible to do by hand as i doubt u could get it out of square with the hole already there, or should i get it put onto a drill press and do it?

5. so i need to buy a large core plug (30mm i think they are), front and rear crank seals and possibly a stock 26 head gasket and oil restrictor, now whats these part usually cost each? can u get cheap generic seals instead of paying $55 for a nissan rear crank seal, etc?

6. has anyone found a rb30 workshop manual online as i need torque specs for the bottom end stuff (rod bolts, main bolts, etc)?

sorry for the huge list of questions, hopefully other people have been there and done it to give me abit of advice :banana:

Edited by unique1
Adriano Grand Master

Adriano

Posted
Posted

I wouldnt worry too much about the crank being eaten away by the seal. You could fit speedy sleeves over the surfaces, but they are about $75 each. If its only a track car, its not going to leak that much oil anyway. Just reuse the metal head gasket, using some coppercote spray. I would just get a set of rb25 head bolts or studs if you want to get fancy. Dont even attempt to redrill and tap the head bolt holes yourself.welsh plug is about $2 try an Auto One, but ive found the cheapest place to get seals is a bearing shop like CBC. Oil restristor can be cheaply made from a MIG welding tip. Just buy one with a hole the right size, about $5.

What oil pump are you going to run? I would be tempted to use the standard rb30 onw, as they dont seem to fail ?!?

unique1 Mentor

unique1

Posted
  • Author
Posted

thanks for the replies...

Adriano, good news on the crank seals then ill leave it and see how i go, ill try cbc for the seals i have bought seals from there before and they are cheap. Metal head gasket sounds ok then, you dont think a deck of the head is worth doing to make sure it seals ok? rb25 head bolts so i dont have to tap the bigger holes u mean? i thought about this and surely the locator pins on the head will keep it central and i doubt head will lift with around 400rwhp and low boost levels, i dont see the rb25s having any issues with head lift.

Ill also be using a low km stock gtr pump from my first rb26 motor which had a genuine 30 000km on it that i bought 7 years ago and changed the pump to a jun one. I plan on keeping power to around 400hp as i said and under 7000rpm so i dont wanna risk using the old rb30 one, who knows how many km's its done.

Dahtone Racing, the engine is a spare motor for drifting mainly and i have another rb26 fully built motor for proper track days, i just dont wanna risk the expensive track rb26 engine doing drifting. Bearings are fine, i'd say they are 90% perfect, if i pay to replace them and the motor lets go on the dyno after 5 min i'll be annoyed, i might not even wanna keep the rb30 as ive never drivin one so this is a test engine to see how it feels compared to the 26. The rings i will check today and make sure they are ok, if not ill replace them.

cheers again for the advice

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

    • Kapr
      Possible swap on R34 RB20DE NEO?

      By Kapr · Posted

      Hi. A little bit of an update. It maybe(hope not) looks like i would need a new tranny(it would be "maybe" a cheaper or better option anyway) So i need some info. I know i need a different propshaft(i can make custom one) LSD is not a problem cuz the engine will be still(for now) N/A RB20. So if i buy RB25DET NEO tranny...is there something else i need? I read something about push/pull type but i do not know if i need to "change" something or i can just plug n play onto my engine a go? Thanks for the advice  
    • OakvilleGTR
      Turn signal wiring question

      By OakvilleGTR · Posted

      Good morning all, Bit of a random question but figured I’d finally throw it out after wondering for a long while. Before I start, I'm hoping to do this purely out of personal preference. I think it would look better at night, and don't mind at all spending a few hours and dollars to get it done. I've copied this from a non-Skyline specific forum, so I apologize for the explanation of our headlight switch setup that we all know. Here we go: Zero lights (switch off) Parking lights (switch position 1) being a rectangular marker on the outside of the housing, my low beam being the projector in the centre (position 2), and a high beam triggered by my turn signal stalk. Most North American cars I’ve owned of this era have power to the amber corner (turning indicator) light as part of the first switch (parking lights). I’d love to have these amber corners receive power when the headlights and parking lights are on (headlight switch), yet still blink when using the turn signal which is of course a separate switch. Hopefully I’ve explained my question correctly. Is anyone aware of a way in which I might be able to achieve this? Thanks in advance
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      My heads are cathedral port! It's likely possible, but I don't want to add any extra moving parts (I know they don't move) between the heads, manifolds, etc. It will also affect how injectors/fuel rails etc sit and I don't really know if it would change how the FAST manifold goes/sits/fits. I have the LS6 steam pipes already as I have a very late LS1 block so it should be fine. I couldn't find anyone who had ever actually used one for this purpose, it seems 100% of people grind the water pump. The thermal spacers are 12mm and are half way to the cost of the newer water pump anyhow... so if it comes to that I suppose I'd rather buy a new pump. The bearing in the pump I do have is a little.. clunky, but it hasn't done that much time and I never noticed it when the car was together in the past few years, so..
    • sonicii
      Lower A arm Skyline v35

      By sonicii · Posted

      The bushing has failed, not all that uncommon for a car of this age.  Any mechanic should be able to push in a new bushing for you, or you can probably buy the entire lower control arm, complete with bushes.
    • The Bogan
      Mistakes were made, my R34 Story

      By The Bogan · Posted

      Could you not use "thermal" spacers to give the clearance, like the ones I used between the blower and head? That raised the manifold height by around 10-15mm Albeit the ones I used were for cathedral ports, but I assume they have similar for rectangular ports????
×
×
  • Create New...