Rb25/30 Na High Comp Build Up

[GTS4WD]

Ok guys.. to answer some of your questions..

I been doing a fair bit of reading and research..

Im thinking I will not be able to complete the WHOLE engine in one go.. especially as Im HEAPS wingey about my suspention.. no point in goin fast if I cant take a corner.. no point in taking a corner if I cant get out of it in time..

so..

Plan of attack..

Bottom end, the cheap headwork and springs and shockies in one go.. then the rest of head and suspention..

mmmkay.. here is how it stands..

Ill be using the RB30 NA (S2) engine as the pistons with an RB25 NA head will give me a C.R of ~8.0:1.

The crank will have to be balanced with the harmonic balancer, flywheel, preassure plate and clutch on it as the engine will be spinning at higher RPM. And yes.. the crank is nitrided from factory.. so no point in strengthening it.

ARP Rod bolts will be used as rod bolts are often the problem of what will cause the rods to shit themselfs.

I may skim over the rods with a very fine sand block to smoothen out the outside edges (Smooth = better flow = Better running conditions = duribility)

The rods I think I will leave stock as they can cope well with 400BHP so the HOPEFULLY 200kw ill be making by the end should be ok for the engine

I will shave the head and deck the block by a total of ~2mm to increase CR to 10:1. Im not too worried about cam clearence as I wont be running too much lift (lift is torue, duration is power). I wont need a big increase in cam lift as I will already have enough poke down low from a high comp 3L with a lightened flywheel to get it revving into the higher RPM pretty quickly.

On the topic of flywheel. I have access to a trade card.. but im tossing up if I should get a second hand flywheel and get it machined instead of buying a new one.

I dont think I will be jumping into porting head myself.. as its a bit of big job.. but a polish will be done in the first stage of the engine work.

Im not 100% yet.. but I should upgrade zorst. I.e. Headers, mandrel bent front pipe, cat (most likely go ghetto and just punch the contents out and weld pipe from one end of the cat to another to help flow). I have a cat back 3" (I know not best size.. bit its a NISMO and got it for $50 to get rid of the nasty metalic resonating). Now.. Id like strip some weight while Im doing this aswell.. so Im thinking.. if I buy titanium piping (anyone got ideas on prices?) and mandrel bend it myself (I have access to a bender) and weld the flanges onto the end of the pipeing and make it my zorst.. I should loose a fair few kg's.. plus its tricked out.. And.. someone bring me back down to earth cos im thinking about cutting lots of little pipes and connecting them so as they bend and make headers.. this will have to be done proffessionally so ill probs have to stick with RB30 headers (as the 25 and 30 have different header alignment) for now.

I only can hope I have enough money by the end (or find some heaps good deals) and have enough money to buy a Z32 ECU That uses VCT (for RB25 VCT head) as these ecu's are mappable. The stock R33 Rb25DE ECU is not mappable. I also have a stock RB20DET laying around at home that can be chipped and re-mapped - but i will loose mt CVT. So just there.. if I need a new ECU/Chip and re-tune.. Im looking at $1000

Further than that.. its stage two of engine work

I may have to fit the ECU and re-tune in stage two.

But now I would need to finish zorst - if its not done and get headwork done. ie. exhaust cam gear. reginded cams (somewhere in the specs of 260* & 8mm inlet and 265* & 8mm exhaust to perhaps slightly higher - 270? 275?) Ill have to talk to the mechanics about this.

Port cams proffessionally

Again - Retune.

Stage one

RB30E Sereis 2 (NA) block ~$80

Balance crank ~$150 (mates rates)

ARP Rodbolts ~$200

Lightened flywheel ~$400 (trade) or ~$200 second hand and machined

Ajustable intake cam gear - $150

Polish - cheap

Deck block/shave head - cheap

Total: at least $780

Stage Two

ECU + Retune/chip ~$1000

Exhaust Cam gear - $150

Regrinded cams - $300

Port ~$250

So yeah..

I think its possible if you do the work yourself.. do the research.. talk to people and learn as much as you can..

I need to start starving myself to save money.

Stop going out

Quit smoking

Continue reading and research

.. and.. SAVE

I still have to see how to run the oil line for the CVT.

So.. comments are more than welcome.. If theres any questions.. please ask.. because I need to be 150% its going to work with RELIABILITY a very high priority..

thanks guys!..

sorry about the freaking HUGE post

[Eug]

sounds about the right track. you can get away with the RB25 ECU and an SAFC for backyard spec.

[GTS4WD]

Well I want reliability.. Thats why im not going higher lift and more CR.

Is there any chance I could have a look at your plan of ur NA engine.. cos I really want to make sure the engine isnt going to shit itself..

oh.. btw..

drop in possibly new bearings depending on the condition of the block..

I also have to see if the RB25DE injectors and Rb20DET fuel pump will fuel it adequitly..

[GTS4WD]

I have heard of RB20DET box's stripping second gear when they hit around 240rwkw and around 210rwkw they start to do their input shaft bearing in.

so it may cost me a fair bit more than first anticipated..

[Eug]

the linear delivery should be fine with the gearbox, i think it's the 'snap' of power which screws em up.

i don't have a word for word plan; but it goes something like this:

bottom end:

- rb30 block, acid dipped, shaved, etc. etc.

- rb30 crank, knifebladed & balanced

- bored cylinders

- forged rods & rod bolts (pick a brand, JE?)

- custom hypereutectic pistons (yet to look into it)

- race bearings & bearing studs (pick a brand, ACL?)

- oil pump w/ crank collar (again pick a brand, Jun from memory?)

- gtr water pump

- dry sump setup, or at least a sump extension.

- ross tuffbond or ati balancer

- balanced everything!

head:

- rb26 head with tuned length trumpets

- ported head

- polished chambers

- port matched inlet ports and throttle bodies

- oversized inlet & exhuast valves (ferra? insert brand)

- 270º cams with 10.5mm lift (from memory, whatever takes your fancy really)

- tomei/jun/etc valve springs (25kg)

- tuned length extractors

- cam gears

- insert brand name headstuds (arp?)

usual:

- d-jetro, motec, microtech, ecu... pfc would be ideal

- splitfire coils

- compression: ~11:1 for pump fuel, 12~13:1 for race fuel.

- surge tank w/ bosch/walbro pumps.

- rb25det box with jim berry's full monty clutch and a cusco 4.8kg flywheel

- 1.5way cusco/kaaz/nismo diff

- 1 piece carbon fiber tailshaft

- lightened pulleys, etc.

should be able to see 9,000~10,000 rpm all day everyday without dramas. of course we are looking at a $10K+ build in parts alone.

in all honesty cris, i think you'll be fine. as long as you plan everything accordingly and make sure you have all your bases covered there shouldn't be any dramas. a reasonably 'stock' build with freshened up bits should see you 200rwkw with reasonable compression and a killer tune.

main points to cover

- balanced bottom end

- compression ratios & fuel avail

- ecu & tuner

- breathing mods; intake, exhaust, head work.

got them sussed, then you're laughing.

keep in mind that the DET guys are running 200-250rwkw on stock internals with no dramas. turbo = pressure, compression = pressure. just be wiery of pinging.

hope that gives you a bit of angle, or even some ideas no matter how far fetched.

[GTS4WD]

Hmm... thats quite comprehensive..

LOL.. some one did their research!

I want to make sure the bottom end is prepped and then Ill worrie about the head..

Ill be looking into throttle boddies etc. at a later date.

I think Ill stick with what I had planned and some rings, rod bolts and bearings.

Ill pick up a universal oil coorler for next to nothing too. Its worth it. I read some people were having problems with keeping their temps down. So its a small price to pay, $50 for a universal oil cooler (I really dont see why you would pay ~$400 for the trendy blue ones)

How do you plan to do a sump extention?

I dont think Im prepared to do all the work you mentioned as yet. I still want to enjoy my car. Besides. I still want alot more suspention and brake work to be done before i go skitzo on the engine. Plus its easier to become a better driver on an underpowered car. so thats another thing thats at the top of my "To do" list.

But thanks for the info. Much appreciated.

Ill be posting up a finalised list of items/jobs and prices within the next few days..

[Eug]

yeah, got a bit obsessed with ideas last year.

the bottom end will be the main component; all the head work can be done further down the track.

you're proposed build is fine, i don't see any dramas with it. just tick all the bases on support gear. like you said, oil cooler, bigger radiator and what not, esp. for revs.

trust make a sump extension that you can weld on. Although a lot of workshops make one in house which are just as good, some are even better with gated baffles. If you plan on seeing revs, you'll want oil!

exactly with the 'enjoyment' factor. with the build i proposed, you're looking at a race spec motor which is going to be a pig to drive at lowish rpm. i mean i'd love to happily rev to 6-7000rpm to pick up my pizza and groceries!

see i've done it the opposite way, all my brakes and suspension parts are done. all i'm after is a motor, so keep us posted on your progress - you can be my guinea pig

[GTS4WD]

LOL!

*insert guinea pig noise here*

Well Im still reading..

*Side note.. some bloke in america payed US$1200 to import an RB30!! and he baught TWO OF THEM!*

But im hearing a common trend with thr RB's becoming unstable over 7500 RPM. So im hopeing the balance in the crank will sort that out.

Im in the process of sending e-mails for prices on the balance and clean/acid dip. Also looking into prices of bearings and rings. Im thinking the race bearing will be better suited to the application.

Ill be getting a full run down pretty soon.. as soon as people write me back and find appropriate prices.

And after slogging through 50 pages of a massive 282page SAU thread I found the .PDF they posted. It wasnt available because the thread was back from 2003.

I have a feeling this thread here will be quite comprehensive after a bit of a clean up.

next time i hear the question:

"What zorst" or "how do i get more power"

Ill just cut and paste the link

[Eug]

jesus! i have an RB30 block sitting in my laundry US$600 i'm rolling in it!

balancing the crank, rods, pistons, rod bolts in combination with a good balancer (ATI or Ross Tuffbond) and it'll be fine. just double triple check and have everything weighed!

nice to see you get started, i don't want to start because i know i'll never be finished

i have the pdf you're looking for PM me your email and i'll send it across, it's current till 29th Sept '06

edit: just thought i'd add, are you keeping the 4wd in the gts4? you'll need to do some sump modifications to allow you're front drive shaft through.

[342Four]

yeah - 6 cylinders are renowned for starting to fall apart at high revs

its cause of the 120 degree angle between strokes - as opposed to a smoother 180 degree between 4 and 8 cylinders

mind you - a guy here in WA has a rb28 with twin gt-ss (i think) that spins to 9000rpm no worries

(but thats a tuffer, internally braced rb26 block....)

[Cubes]

Balance the crank all you want it won't help.

The problem with the rb30 is it needs decent rods to rev.

Much or anything over 7500rpm and they begin to have issues.

Throwing lighter forged pistons on to the end of them does help but in the end.... Your going to need a set of forged rods if you want to rev it reliably.

Just like the rb26 or the WA RB28 bloke; I'm sure that runs a set of forged rods.

[342Four]

well its a tomei rb28 stroker kit and i think they are forged rods.....

all in an n1 block

mmmmmmm

[GTS4WD]

jesus! i have an RB30 block sitting in my laundry US$600 i'm rolling in it!

NO NO NO! US$1200 EACH!!!

"They are $1200 each."

i have the pdf you're looking for PM me your email and i'll send it across, it's current till 29th Sept '06

Lol!.. yeah!.. only by coincidence, whilst looking for RB30E bearings did i bump into it over google.

There seems to a little more work than first anticipated

bur faaaaaaaaaaaaaaaaaark!.. this file is going to help me a BILLION fold!

edit: just thought i'd add, are you keeping the 4wd in the gts4? you'll need to do some sump modifications to allow you're front drive shaft through.

lol.. ill cross that bridge when I get to it..

lets just hope its not some big f*ck off bridge!

The problem with the rb30 is it needs decent rods to rev.

Much or anything over 7500rpm and they begin to have issues.

Throwing lighter forged pistons on to the end of them does help but in the end.... Your going to need a set of forged rods if you want to rev it reliably.

I have a set of RB25DET forgies laying around at home.. but I have a feeling dad has shot gunned them for a future project.. besides.. the amount of shaving and decking involved to bring the CR to a decent level is purely SPASTIC!.. so that plan is out the window..

Well.. what are my optioins?

By no means do i have the $800 on top of the build funds to pay for aftermarket rods.

Could I get them shot peened?

Nitred?

Cryogenically treated?

A cheaper alturnative?

I dont think Ill be pushing it past 7000RPM as its a stock RB25DE head and wont be modifying that till a later date. I do do alot of togue and mountain passes.. so Ill need to make sure the engine has adequit oil and oil preassure.. Ideas anyone?

[GTS4WD]

I remeber reading somewhere rod bolts help in engines to rev higher?

Confirmation?

it was something along the lines of: "if the rod bolts are stronger, it helps stop the rods from flexing?"

mind you this was at the top of Mt Panorama during the Bathurst 1000.. so both of us were on the cans pretty hard by then.. so traslation may have been lost

[Eug]

by balancing the crank; i (and anyone with half an idea) would be balancing anything else attached to it. rods, bolts, pistons, gudgeon pins, and every other part that goes around and around. however if you're not exceeding 7K, then it should be fine.

ashley is correct with the I6 falling apart due to its stroke angles. it's not the most ideal engine, but it's been done before and many RB25/26/30s and M3s rev happily no dramas. if everyone was anal about having the best motor config, then we'd all be driving around in 2.4L V8s.

in regards to the 4wd; it's not a big bridge, but it will add to the budget you'll need an sump/diff adapter plate thing.

[342Four]

fitzpatrick speed works does modded sumps to mate rb30 blocks to the 4wd system

i think he still is a user on here

try that...

[GTS4WD]

WOOOO!..

thanks for the help guys!.. been emense help!..

I got a few quotes back.. today:

Price on block would be $260.00 balanced with piston and con rods.

Dip cleaning is included in the price.

RB30 1500hp con rods that have upgraded bolts in them $1620 inc.gst.

So i think ill wait for my other quotes to come in about balance and dip clean.. I may even see if I can clean it myself.

and $1620 is stupendus! Ill be getting them when I plan to run 13:1 CR.. if i ever do.. but for now.. Ill get rod bolts..

Ill give fitzpatrick a pm. See what he sais about front sumps/diffs..

Thanks again boys!

[LedZepLen]

Think of the pressures a stock turbo engine is taking with just the stock turbo boost maxed and that the same engine can take allot more with a bigger turbo and no modifications before your left on the side of the road.

Guys run arround town with 14.1 comp 454's on pump gas. I dont see why your engine wouldn't take 12.1

[GTS4WD]

Think of the pressures a stock turbo engine is taking with just the stock turbo boost maxed and that the same engine can take allot more with a bigger turbo and no modifications before your left on the side of the road.

Guys run arround town with 14.1 comp 454's on pump gas. I dont see why your engine wouldn't take 12.1

Its a good point.

Im looking into some "prepped" rods which come with ARR rods atm. not sure what the seller means by "prepped" but im waiting for a reply.

SKiT_R31 is running RB25DET pistons. I have a set of forgies laying around at home. So if all goes well with the seller and the RB25DET pistons are appropriate (I remeber reading somewhere the piston pin sits higher, hence the piston is lower and therefore lower CR than the Rb30E NA pistons.. confirm?). If all is well in this sence.. Ill most likely run 11 MABY 11.5:1 CR. Ill see if a stock RB25DE fuel system with an RB20DET fuel pump will provide appropriate fuel pressure for the higher CR.

[GTS4WD]

Ok guys!

currently awaiting shot peened rods and ARP bolts!.. Project is a GOER!

Shopping list is as stands for the moment:

Bottom End:

3L Bottom end ~ $150

Series 1 (thicker block walls + no oil turbo feed) (Non turbo – CR)

Acid Dipped/Cleaned? ~ $70

Balanced crank ~ $100

Bearings ~ $80 - Necessary?!?! Big end bearings AND mains? or just one set?

Decked block 2mm = ~10.5:1 CR

Con Rods

Shot Peened AWAITING

Rod Bolts (ARP) AWAITING

Lightened Flywheel

E-bay Flywheel ~$267 + Post

Oil Pump

Crank/oil pump collar ~$70

Rb25DET/Rb20DET?

Timing Belt ~$100

Headers – Group Buy $180 + $60post + Heat wrap $50

Oil Cooler ~$150 + Hoses OR E-bay Brisbane ~$300 Hektic Blue

Total: ~$1200

Now.. Question?

Should I use my current Rb25DE pistons? Pro: Saves me from buying new rings, better condition than 200,000+km Rb30 pistons. Con:I have a useless rb25DE block, inclomplete.

Use Rb30 pistons. Pro, can sell rb25DE block, complete. Con. Worse for wear and need new rings

Shave the living sh*t out of the block and use rb25DET forgies I have at home laying around.

Thoughts? comments on shopping list or pistons is muchly needed!

Thanks guys!

P.s Anyone have a lazy RB30E block laying around they want to get rid of?