25 Neo Head On An Rb30? - can it be done?  

gutless

Yes it fits and has been used
n/a is too expensive unless ur obsessed
turbo is the way

Rancher

Wait. Wat? How is going the N/A route more expensive? That makes no sense at all.

gutless

too expensive for the gains you are making

Rancher

... You getting more torque then a standard RB25DE, and much more HP then a standard RB30E. Its not really that expensive to build an RB30DE or DET. If you spend a $1000 and get an extra 100RWHP and a couple hundred torque.. Thats money well spent. Its probably exactly the same gains as DET as DE. You know, you dont have to spend the extra money on the turbo charger/lines/manifold/intercooler/piping to suite.

gutless

Well Im under the impression
that if you just fit a 25 head to a 30 it won't last
especially if you turbo it

KammdUP

how much power theoretically could you get out of a n/a 30/25 with bigger cams and porting and head work and hi comp pistons? with a forward facing plenum and good exhaust

gutless

Just look through the r31 skyline club forum
all the info is there

na and turbs

Rancher

A guy on SAU built an RB30DE 5 years ago, using the VVT head. Made 123RWKW. Standard cam etc. Did a 15.1 down the quarter.

http://www.skylinesaustralia.com/forums/to...0540-my-rb30de/

gutless

pretty cool
and that's using the old 33 Vct head
only had 10 degree lift under 4700rpm
neo head has proper vvt

TwinCam16

Err no it's not

There is no such thing as a RB with VVT.

Do you realise what an RB neo is?

gutless

ok can we settle for it having a better version of vct?

TwinCam16

It's the same VCT.

Ill ask again.

Do you know what is different on the 34 and 33 motors?

gutless

Solid lifters
I was told the turbo was ballbearing but don't know
can't remember where I read that vvt thing
but yeah don't know too much about neos
and not gunna go research right now to prove I know things I dont
my bad.

TwinCam16

All good.
It's just like the S14 / S15 SR20's and people thinking they have VVT as well.

sanchezz

lol..
it is a lot more complex then simply screwing a 25 head onto a 30...

if you were spending the money to do that i would be going all out with steel rods/crank etc..

zacy-g

I've heard it's well worth the money spent putting a twincam head on a 30 block, whether its N/A or turboed..

There is a guy on 31club who is nearing the end of a 26/30 N/A build and has spent something like 10 grand doing it, but he hasn't cheaped out on anything..

dirty turbo

good gain vvt oil gallery has to be modified extra cam belt tensioner differnet pistons small things really big write up on sau forum about twin cam heads on rb30 blocks

iamhappy46

15.1 is still slower than a stock SR20VE swap into an N14 Pulsar.

TwinCam16

I did 15.2 with a stock SR in an N15

matmarhar

do u have a 25 neo head sitting around or something? i have just finished 2 years of building my silvia and the rb2530 fitted in it. I have not had it tuned yet so cant help u with gains and stuff but i can tell u it was a very costly excersise. granted everything on mine is brand new and theres no cheap shit on it atall

silver31

But you don't get an extra 100rwhp or a couple of hundred ??s of torque.

Bang for buck its a losing game UNLESS you are just using your head and supporting mods from a car which has a blown up bottom end (i.e. GTS-T/GT-T/to some extent a GT-R).

Otherwise, if you have an R31, a RB30E+T will dollar for dollar be a better powerplant. If you have a GTS-T/GT-T with a healthy engine you'd be far better off spending the thousands it will cost to make it all work on other supporting mods to the original motor.

Ra ra in theory its better, in real life the gains aren't there. If you go through the SAU thread most of the engines either make the same or slightly more power than the alternative, just at considerable cost and slightly lower boost.

09ONE

Oh so you have built one have you? Please do tell how you were able to build one which was "not really that expensive"






Took me ~18months to build mine, no expense spared either (didnt go dry sump though) and had to re-adjust my budget 3 times. Very costly exercise. Have had mine for a bit over a year now and the gains are kinda insane compared to a RB25. Full boost 1000rpm earlier and the fattest power/torque curve!

Jive Turkey

pretty sure I saw one for sale in the classifieds neo rb30et
but I don't believe in this whole very expensive approach to it, you can spend as much money as you want on an engine, but this can be pretty cheap if you know how to shop.

matmarhar

what car did you put yours in? only asking because i am still trying to sort out a bonnet option that isnt rediculously ugly for my car because it doesnt quite fit under my standard bonnet unfortunately

PandaSil

Use bonnet spacers under the hinges.

matmarhar

its a fair way from clearing cause i have a high volume sump i couldnt mount the engine to low diddnt want the sump the lowest point . and because of the extra height of the rb30 block there was just no way of making it fit under unfortunately.

PandaSil

Is it an s13?

matmarhar

yeah

PandaSil

Thought as much, How much room do you need to clear? in mm?

matmarhar

have u done one b4 or something?

PandaSil

I've seen it done before and I know someone that has done it.

They used the same sump as you mentioned but built a protection plate for it under the car.

Also raised how the bonnet sat, I'll see if I can find pics. as it is with a 25 in an s13 you need to raise the bonnet a tad so it can fit.

AssViolator

Dont waste your money.

The sohc rb30 goes well with bolt on turbo kits. The money wasted on fitting a rb25 head could be spent on turbo kit for what you have.

matmarhar

if it was a 25 it would have fit in its just due to the extra 30 odd mm in the rb30 bottom end and the sump screwed me a few mm havent measured exact clearance needs yet but at a guess its probably somewhere round 40 to 50 mm needed at the front of the engine

KammdUP

not for my car, just thought it would be a cool project, saw an n13 pulsar with a vct sr20 kick out 135kw at the front wheels almost sounded like it had vtec was BLOODY quick too hahah so i thought maybe the same sorta thing could be done with an rb30/neo and make a nutty atmo 6