Full Engine Rebuild

[croat]

In the next few months will start to bolt up the GT35R to my R33 gtst. at the moment i have it with a 0.83 exhaust housing. Will be bolting this up on the standard motor so not expecting it to last long.l What i intend to do is rebuild the motor again but with forgies and the lot.

One thing i have considered is stroking the motor. I have heard of the tomei 2.8L kit for $7500 with with crank/rods/pistons. Rather than forking out this much can i use a GTR crank? will this stroke out the motor? How much? has anyone done this? what exactly is involved.

im not too cluey with all this stuff so any help is appreciated. what costs are invlved with a reliable 400rwkw rebuild?

Thanks..

[paulr33]

rb30det instead

[Guest acxacx]

Good on you lol. i'm croatian also and i dont have the answer to your question soz. just saying hi

[r33_racer]

2nd paulr33

RB30det

[croat]

was strongly considering doin gthe RB30 but i want the car to rev hard. 7000rpm is just not enough for me. i know with this turbo i can easily make the power i want with a stroked 2.5. So anyone know how the GTR crank goes?? what has to be done??

[paulr33]

the point of the rb30det is more displacement,. you wont need to rev past 7 grand. it will make its peak power near 4 grand instead of 6 (rb25 style).

so theres no need to rev it so high. you are much better off revving lower (less loss and friction) than revving to 9 grand (rb20 style)

[Black Betty]

you'll never get 2.8l consider than the larger rb26 black uses a GTR crank and its only 2.6 litres. you get about 2.55 or something.

i was considering a similar operation for my rb20 but the machine cost for the block are huge - it would be slightly less for an RB25 but still very costly.

you could put forged pistons and rods in the 25 and with that turbo and a really good ecu you should make 400 rwkw but seriously if your gonna go that far just get a new block 26 or 30 and slap your 25 head. if you use a GTR block crank rods and forged pistons and a good ecu you be able to safely support 400rwhp... for a while. there's plenty of ppl on here selling their GTR bottom ends.

talk to a workshop or machine shop for quotes because you HAVE to get the stuff machined, if you don't you blow gaskets like a prostitute.

RB30's are probably the best option.. although i'd like to see someone put a barra 204t in a skyline... see my signature.

[Black Betty]

agree with not revving hard. i have to rev my 20 to 8G in 2nd to get the best pull into 3rd gear.

putting in a larger crank means machining the block so that it will turn and not hit the sides with the larger rod bolts it requires

also i think you'll need new rods because the stroke with the new crank will be wrong (longer or shorter i'm not sure) and you will need new pistons to hold up 400kw.

on top of that when you build a new engine you always getknew rod bolts, head styds etc and like i said before you get it machined. muchos deneros needed

[croat]

paul yeah i understand that is the advantage of the rb30. i also understand that the mottor does not fit too well in an R33 engine bay (clearance issues with bonnet). i feel if i start with the rb30 i will be opening a basket of problems.

[croat]

i was told that the gtr crank wil give me 2.71 litres. and ill stil be able to rev the motor till like 8,000

[paulr33]

the problems with the rb30det i dont believe are massive

just need some planning to work around it

a read of the rb30det guide should clear up any questions

[Shwartz_sticker]

I have an Rb30det, if a drysump system is used, the engine is quite capable of revving up to 9000rpm. P.S. The engine is up for sale if your interested (rb26/30)

[Craved]

front facing plenum = fixed

[The Dan]

Rb30DET is not the answer.

The 25 has a greater flowing head than all the others so it is by far the best choice for modification. You can go to an RB30 bottom end and retain the 25 head which has proven itself many times before. There are some problems in block design that need to be remedied before you could consider it a reliable option.

You will need around 2 grand to spend on porting and you will also need a decent cam like a HKS step 2 or step 3 if you want the funky idle.

Retain the standard crank and rods but have them shot peaned and nitrided or cryo treated. There is absolutely no need to go to 2.7 or 2.8 litres to achieve a small figure like 400rwkw. The GT35R you have will max out at approx 450rwkw anyway so you'll probably need to be running in excess of 24psi to get your 400. This means dish pistons. Don't muck around with gay metal head gaskets coz they are a waste of time and are not as durable as the standard factory head gasket.

You will also need a full ARP stud kit for the entire engine.

Make sure you tackle issues like oil control in the head with your engineer as this is a major issue in the RB's. Not only getting the oil in there but getting it out again.

If you want the engine to be reliable at that hp figure you should consider AT LEAST an N1 oil pump but I would highly recommend a JUN item which will definately outlast the N1. You are going to need to upgrade your throttle body at least and should use an aftermarket plennum while your doing it. All of the inlet piping will need to be 3 inch and the intercooler should be an efficient bar and plate design or something at least 600 x 350 x 100. PWR make some very nice coolers that will do the job nicely.

Don't forget about driveline either as the standard g/box will need to be upgraded to dog engagement and you will also need a decent twin plate like the one I sold R33skyliner. It is the same one used in Mark Jacobson's 9 sec GTR.

Don't worry about the driveshaft too much and definately don't go to a one piece tailshaft if you want to be able to rev the engine past 7 grand. One piece 3 inch tailshafts go critical at around 6500 so big bangs can happen after this point. It is better to retain the original unit but upgrade the centre bearing and unis.

[The Dan]

I have an Rb30det, if a drysump system is used, the engine is quite capable of revving up to 9000rpm. P.S. The engine is up for sale if your interested (rb26/30)

Why do you need a drysump to rev to 9k. My Rb20DET revs to 9k several times a day with no hassles.

[Shwartz_sticker]

IF you would read the thread you would see that the rb30 is not really meant to go that high. The difference with the rb30 is its displacement level. Your rb20 is quite different.

[paulr33]

what on earth?

stock rb25 head

stock rb30 bottom

poor mans rb30et pistons

suitable injectors

suitable ecu

suitable exhaust

stock gaskets

suitable manifold, gate, turbo

should make 300rwkw relibably and easily.

you are reading too deep into it 3litre32

[paulr33]

sky30:

My Rb30DET in a R32 skyline

Stock RB30 bottom end from a VL commodore (300,000+kms)

Stock RB25 n/a head, Stock cams with heavier valvesprings

Stock exhaust manifold with GT35/40

Stock plenum/inlet manifold

3 inch exhaust

FMIC

550 cc injectors and bosch 044 pump

Microtech ECU

Made 306rwkw on 20 psi with 550nm torque, have since added 260deg cams and made 312rwkw with better midrange power & torque.

Power peaks at 5800rpm, then drops of pretty quick, i suspect this is caused by the stock exhaust manifold which i will change soon.

[paulr33]

Guilt-Toy

R33 GTST

RB25det head with VVT oil line

Standard Bottom end rebuilt with new rings and bearings only

Nismo 740cc Injectors

Sard Pressure Reg

Walbro 550 pump

Plazmaman Plenum

300x600x100 Intercooler

Extractors

GT3540 .82 rear Turbo

Tial 38mm Gate plumed back

Power FC & HC

3" exhaust

Made 346.6 RWHP on a conservative tune (low timing) on 16psi. Will post pics and dyno sheet. Got it tuned on Saturday and the dif blew on sunday lol. Bit worried about the bottom end so I did not go above the boost level sydney kid recomended.

[paulr33]

conan-7772:

RB25/30

Stock plenum

Stock cams

Stock injectors

Stock head, serviced, ported & polished

Stock exhaust manifold

Rising rate fuel regulator

Rev I-beam Conrods

CP Pistons 8.3:1

CP Rings

N1 oil pump

Powermax water pump

ARP main studs

ACL Race Series Main and Rod bearings

ACL Valve Stem seals

3 inch exhaust

Haltech E6K management

Haltech ignition

Haltech boost controller

No AFM, map sensored

Front mount intercooler

911T Fuel pump + surge tank

High flowed turbo , Hitachi internals, looks like stock housings to me but compressor housing possibly different.

Compressor housing bored to take a 56 mm wheel(inducer) , 500 hp bb core , Exhaust housing bored to take a larger steel wheel, size unknown. Pics of turbo posted in discussion thread.

Apexi BOV

Tuned at 15 psi due to lack of fuel delivery mellow.gif

Injectors at 96% duty, fuel pressure on full throttle 68psi

293.7 kw and 462.7 Nm