Rb25/30 Engine Build

[Fitzpatrick Speed Works]

no rb30 I have every seen has oil squirters! Thats about 32-35 at last count I have 9 in the shed and none of them have them.

A 26 head is a far better choice you will find the 25 cam, and valve choice limiting to the power figure you are hoping to achieve.

A well prepped standard crank should be okay, just be sure to run a good dampner, and a really good quality clutch that is balancd also. Also balance each rod and piston assembly.

Also consider an Autronic if you are willing to rewire the car ecu from scratch you have as good results as MOTEC and if its not a dedicated race car alot of the Motecs systems are wasted on you, so for half the price the Autronic might be an option.

I would budget $8K for a bottom end

I would budget $5-6K for head work and plenum not including the purchase of the head

About $5k for the driveline, mechanical diff, gearbox rebuild and good clutch, and tailshaft service.

I would then budget 5k for miscelaneous like fuel system, ecu, ignition, wring etc.

So yeah its expensive for that much power, if you have more questions fire away.

[Sydneykid]

I know sydneykid has a few tips he just wants to tell us 

You rang

1. Why the HELL would you use an RB25 cylinder head? :lol:

The RB26 head WILL cost less when you include ALL the necessary parts. Think about inlet manifold, plenum, exhaust manifold, camshafts, solid lifters, valve springs etc etc. Aftermarket RB26 parts are far more common, more choices, cost less new and are plentiful used.

2. I have never ever seen an RB30 with oil squirters standard, and I have disassembled over 30 of them myself, Commondoor, turbo and N/A, series 1 and series 2, Skyline, Patrol and Nissan forklift. Maybe I have just been unlucky

3. Standard RB30 crank is OK, I have seen 925 bhp on the engine dyno. But there are lots of tricks to get it to live at the necessary rpm. Tricks I am sure the RAAF doesn't know :lol:

4. If you are not going to circuit race this engine regularly then why the HELL would you use an N1 water pump? They are designed to avoid cavitation at sustained high rpm, on the road they are useless. A standard R33 GTR water pump is the go with a 50 mm PWR radiator.

5. I sure as HELL wouldn't be using a wide flange drive N1 oil pump on an narrow flange RB30 crank without an adaptor collar (ProEngines have them).

6. Forget about using the standard RB25 box, it MIGHT hold the torque. But the ratios are all wrong for that sort of engine, it WILL drop off boost on gearchanges without a close ratio gearset.

7. Almost NOTHING in the drive train will handle the torque, everything wil have to be upgraded. That includes the tailshaft, universals, diff, drive shafts, uprights, rear cradle etc.

8. I have been looking at the T04Z for circuit work for some time. But the average power over the rpm range we need looks like being less than the ITS66 we currently use, so it would be slower. Until I get a compressor map for a T04Z I don't think I will be risking it.

9. I most definitely wouldn't be using an R33 chassis for this, the R32 chassis is much lighter and leaves more of the budget to be spent on the go faster and/or round corners stuff.

10. At that sort of power and rpm don't forget to factor in a full engine service (rings, bearings etc) around once per year.

11. Based on my experience, whatever the engine costs, double it for the rest of the modifications required to handle that sort of power.

cheers

PS: Last year we built 5 engines similar to what you are describing, the bill for each was $18K plus turbo, injectors and exhaust manifold.

Edited February 14, 2006 by Sydneykid

[TTT]

ouch

[Fitzpatrick Speed Works]

Gary how is that rb30 GTR engine going that MIlton sent to the UK going??? IS it up and running yet??? IT should have around this type of power

[Sydneykid]

Gary how is that rb30 GTR engine going that MIlton sent to the UK going??? IS it up and running yet??? IT should have around this type of power

<{POST_SNAPBACK}>

Nope, they are still building the chassis. There will be two more running locally before that one.

cheers

[2BNVS]

i made 352rwkw@16psi on my 25/30 if u need more info on whats done and cost pm me

ben...

[BOVed]

I dont understand you guys if youve got that much too spend and still not sure wether your going to get a reliable engine, just jap have N1 GTR RB26 for $12800 if i had that much to spend thats the way id be going!

[Fitzpatrick Speed Works]

why is a n1 more reliable mate??? Just cause its a thicker casting doesnt make the engien more reliable!!! Put it this way I have never had any rb30 split a bore or do any damage to the block itself, and I have never heard of it that was a direct reult of soemthing else being wrong ie. it threw a rod or the tuning was wrong!!! A 2.6 litre for $12K if thats the way you would go then I think your crazy but that just me and I am on the other side of the coin to you I guess???

why is a n1 more reliable mate??? Just cause its a thicker casting doesnt make the engien more reliable!!! Put it this way I have never had any rb30 split a bore or do any damage to the block itself, and I have never heard of it that was a direct result of soemthing else being wrong ie. it threw a rod or the tuning was wrong!!! A 2.6 litre for $12K if thats the way you would go then I think your crazy but that just me and I am on the other side of the coin to you I guess???

[TTT]

how did you manage a double post.. in the one post? hahahahaha

but good point.. points.. twice..

[Fitzpatrick Speed Works]

thats so weird but cool I dont know how that happened???

[BOVed]

why is a n1 more reliable mate??? Just cause its a thicker casting doesnt make the engien more reliable!!! Put it this way I have never had any rb30 split a bore or do any damage to the block itself, and I have never heard of it that was a direct reult of soemthing else being wrong ie. it threw a rod or the tuning was wrong!!! A 2.6 litre for $12K if thats the way you would go then I think your crazy but that just me and I am on the other side of the coin to you I guess???

I didn't mean its more reliable, I put that the wrong way what I shouldve said that if its going to end up costing close to $25k to get RB30 right and the mods to let the rest of the car handle the power then why not just spend just over half that on the 26 ans still have a f***ing fast car, unless your going to drag it who needs that much power youd want own a buerepairs franchise to keep fitting tyres!

[N I B]

N1 block is not thicker its very much lighter than the standard block.

N1 blocks running over 650hp crack a lot sooner than standard blocks.

I have cracked N1 blocks at work.

[BOVed]

N1 block is not thicker its very much lighter than the standard block.

N1 blocks running over 650hp crack a lot sooner than standard blocks.

I have cracked N1 blocks at work.

Fair enough i just thought from what Id read about the N1 R34 GTR that it was a f***ing nice engine point taken

[N I B]

N1 block is not thicker its very much lighter than the standard block.

N1 blocks running over 650hp crack a lot sooner than standard blocks.

I have cracked N1 blocks at work.

[TTT]

it's double post city here..

[sky30]

BOVed- What makes you think a RB30det costs $25,000???

My cheap setup owes me about $6,000, it makes 312rwkw, and 590nm of torque at the wheels. I dont think a RB26 would get any where near that torque when at the same power level.

[shanef]

I think he means the price of the setup i'm going for.

Also why the hell would you spend $12 800 on an N1 engine when u have to spend all the rest on it to bring it up to the level of performance i want? That's just a waste of money. Not to mention the wast of an n1 bottom end.

[sky30]

I think he means the price of the setup i'm going for.

Also why the hell would you spend $12 800 on an N1 engine when u have to spend all the rest on it to bring it up to the level of performance i want? That's just a waste of money. Not to mention the wast of an n1 bottom end.

What setup you going to run?

[blue demon]

ok i have a few questions here i am lookin at doin the same 2 my engine, i have the r31, rb30 engine ok, is it possible 2 say 300rwkw with lpg if ne of u no some1 whos done it let me as i have seen a vn i think it was put that much out with lpg and also would it b better 4 me 2 just save my pennys and buy a r32 with the rb30det and go from there im just lookin in2 it atm ive been told many different things about this setup and i would like them clarrified, so if u can provied more information then whats in this thread so far that would b great pm me if u want 2 thanks :

[TonyRB25]

has anybody done this conversion with the rb25det head? if so i need help with it wat is needed for the prep of the block for it to go on and run properly and with the vct how will that work on the 30 block? if any body can help it would be greatly appreciated....thankx in advance please pm me or email me at [email protected]

Edited April 5, 2007 by TonyRB25