Blown My Rb20 :) Conversion Time?

[zertek]

hey guys,

Recently i bought myself a R32 GTS4 (RB20det) from QLD, Cairns. I live in Adelaide so i got it transported down here. I have family in both QLD and SA so im kind of back and forth, I should only be driving it in SA though. My plan was to keep it registered in QLD to avoid unnecissary defects in SA. I have 1 week left to transfer the car into my name before it needs to go through another RWC.

It is a decently modified street car, which is now my weekend car. On my 6th time driving it, i encountered an engine problem, (I'm no expert and im trying to soak up as much information on mechanics as i can) from what people have told me, ive blown a head gasket. I had to drive the car home for a few reasons, which im sure caused further damages. (i suspect the car was making around the 220rwkw mark while it was running).

I have been quoted around $1500 from 4 workshops to replace my head gasket and machine the 'corroded' heads as all workshops said would need doing. On top of that i dont know what else could be wrong. This price has sparked my head to wonder about other alternatives...

My mind is sort of set on converting to a RB25det, RB30et or even a RB25/30det combo, as i like the extra power down low. I'll be using the same turbo from my last set up (GT25BB400R 0.64 turbine 0.7 compressor 400hp Garrett.) which was extremely laggy on the 20.

I'm chasing power figures of around 270 - 300kw at wheels (i want this to be fairly conservative and safe power). My car runs a GTR gear box so it should be able to handle the power. Id love to hear from any 32 GTS4 owners with power figures around the 270 - 300kw range (or even more!), and hear what conversions, mods they have used. And off coarse im open to hear anyones advise....

My main questions:

- What engine would you go with?

- What has to be done regarding rego and rwc in QLD after an engine conversion?

- Approx. price on a particular engine setup that you recommend?

Thanks for your time...

~ MIKE

[lwboosted]

i am currently in the same position.. and i have gone with an rb25det.. an rb30det is a lil to much for what i want to do and spend..

in terms or reg and rwc.. i dont know how it is in queensland but there is a gray area in vic, r32 did come out with a rb25de and for them to accept it you need to prove that it came with that engine.. and if i need to i will just pull the turbo off for them to accept it then put it back on.. or you can just get a engineers for arrond $600 but you may need to change other things like breaks, etc...

if you chasing 300rwkw you will need a bigger turbo and eventually need a rebuilt engine.. it really depends on how much you are willing to spend, how much of the work you can do, and much you cant do to determine price..

there is alot of information on this site about this so do a search you will find the information you need.. hope what i have said makes sense..

[zertek]

thanx mate, im also considering converting my RB20det into a Rb24det with the gtr rods.... Has anyone here done this? what sort of power can these engines pull????

[Bl4cK32]

Id be pulling apart the old motor to determine what exaclty went wrong first. If it was a blown head gasket it wont mean a corroded head guaranteed.

In a bi metal engine when it overheats the head and block will change their temps causing the seal the head gasket has to break, causing the blow.

People say u need to reskim the head as it will have warped when it overheated, and that the head needs to be tested for corrosion. I dont believe in doing all that if u can see it looks ok, and test for straightness on the mating surface. (im a dodgy bastard, but it saves heaps of money.) *insert flaming "oh noes its gunna blow again, u need to do it right" replies quotes below Do all the labour yourself and u should come out of it very cheaply.

Rb30det would cost as much as the 25det route, dont even consider the 30e. 30det can be done on a budget as well, no need to go uber the top.

But sort out what went wrong first, before slapping in a new motor. Plenty of guys in SA have done the 30det (including the 4wd), so ask and u will receive help.

Edited May 14, 2007 by Bl4cK32

[zertek]

Id be pulling apart the old motor to determine what exaclty went wrong first. If it was a blown head gasket it wont mean a corroded head guaranteed.

In a bi metal engine when it overheats the head and block will change their temps causing the seal the head gasket has to break, causing the blow.

People say u need to reskim the head as it will have warped when it overheated, and that the head needs to be tested for corrosion. I dont believe in doing all that if u can see it looks ok, and test for straightness on the mating surface. (im a dodgy bastard, but it saves heaps of money.) *insert flaming "oh noes its gunna blow again, u need to do it right" replies quotes below Do all the labour yourself and u should come out of it very cheaply.

Rb30det would cost as much as the 25det route, dont even consider the 30e. 30det can be done on a budget as well, no need to go uber the top.

But sort out what went wrong first, before slapping in a new motor. Plenty of guys in SA have done the 30det (including the 4wd), so ask and u will receive help.

Doing the labour myself would obviously be the cheapest option... but I have no idea on how to replace the head gasket and check for what ever else that may have gone wrong. I may aswell take the engine out and have a play with it, pull it apart and learn a thing or two. If i stuff anything up, its just as cheap to buy a second hand rb20det as it is to rebuild one.

Looking at prices online... i think i could come up with a 30det just as cheap as buying a 25det... so why the heck not?

[zertek]

Ok ive decided to go ahead and go the RB30det. I'm using the guide that can be found in cubes signiture.... I'm no engine builder so i can see myself hitting many walls when attempting to get this thing together.... It will be a long wait, but im sure the torque will be worth it!

[TTT]

before you start..

consider this..

your car is 4wd. therefore you need a sump adaptor.

therefore the engine sits even higher.

being 4wd, you can't re work the engine mounts to lower the engine a little as it will screw with the 4wd system.

Therefore, you will need to get a new plenum AND trim the support on your bonnet.

OR

use an Rb26 head and still trim the bonnet support.

because of the RB26 head, you will need to have a new manifold put together for a single turbo.

because of the rb26 head, you will need to have the rb30 block redrilled to suit the new larger studs of the rb26 head.

Because you now have an RB26/30 engine, your pissy 400hp turbo is going to be useless and be on boost all the time and die off early in the rev range.

therefore, you will want a GT30 of some sort around the 500hp region.

Since you are using an RB26 head with nice new large turbo, you think to yourself, do I really want to bolt all this good stuff to a 300,000km 1987 built rb30 from a VL which was probably never looked after all that well.

I might as well get one of those fored pistons and rods packages from that guy on these forums..

Then you realise that the bottom end should probably go in for a good clean and check and test.

then you get worried that you might ruin something trying to put in your brand new forged $$$$ bits so you deliver it all to an engine builder to do all the machining required and get it all working.

I could go on if you want more of my "stories of the guy who thought about doing the same thing"

You want a cheap fix?

get it to a mechanic to fix the gasket.

you have little bit more money?

find your self a Stagea front cut (rb25 with 4wd sump which you need)

you got even more money?

be one of those "I wanna be different" guys and get an RB22, 23, 24 built.

you got rich daddy who gives you what ever you want?

go to fancy performance shop., drop car off, give them blank cheque, tell them you want an RB26/30 combo which produces a rebliable xxx rwkw and to call you when it's done.

[Cubes]

There's a bloke selling his rb30det gts4 setup in the foresale section. He's in adelaide too.

He is willing to seperate so grab the bits you need.

The hard work has already been done adapting the 4wd sump adaptor and sorting out the oil pump pickup, if you were to grab the bottom end remove the crank and have a crank collar fitted and throw it back together maybe with a set of new bearings.

Might be worth looking in to.

4wd + RB30DET + GT35r .82 is near the perfect combination for close to 400rwkw with power coming on well from 2000rpm and hard from 3500rpm.

Start planning to keep it looking stockish, so space the subframe down and lower the motor slightly so you can retain the std plenum. OR.. Go for a set of twin gt2530 (gt2860-5's) with a GTR head for around 350rwkw.