Rb20/30 Build

[DRIFTER]

i'm in the process of collecting parts for the build, so far i have have a complete blown up rb20. i've found some gtr cams but i would like fial conformation that you can use them with the 20's hydrolic lifters. i've also been having trouble trying to get information on this conversion so if anyone has done it recently i'd love to pick your brain, mainly on whether you need to modify the combustion chambers and what needs to be done with the oil restrictors and drains.

also i am having over heating problems with the car, so i am in the market for a BIG alloy radiator. what does everyone use and recomend. thanks for any help you can give me

[Bluprint]

I've known a few people with R33s have stuck an Australian R31 RB30E radiator into their cars and are happy with the results. They're a twin core design. I got another brand new one when my Neo conversion got back on the road and I reckon it's brilliant.

Though if you want to go all out I'd be going to PWR I reckon.

One of those 100mm thick jobbies with a big arse thermo fan.

Edited November 2, 2005 by Bluprint

[FATGTS-R]

Just to clarify, are you going to build an RB30 with RB20 head? Or have I misunderstood?

[FATGTS-R]

"double post, ignore"

Edited November 2, 2005 by FATGTS-R

[gtst4d]

thats is his plan .

[FATGTS-R]

The reason why you are having trouble finding info on the conversion is because very very few have done it as opposed to fitting the RB25 head because its easier and the performane gain over the 20 head is a lot greater.

But I am sure you have been told this many times by now.

In the last 5 years I have only ever seen one Rb20/30 conversion in a VL which was in a magazine. And from memory, it was a hell of a job and the reason it was done was because the RB25 had yet to be released.

[R31Nismoid]

well someone tell the man he is crazy (ive done it and it seems he doesnt listen to me)

the RB20 head does not flow enough to cater for the RB30 bottom end.

If it did... eveyone would be using them as they are far cheaper than a 33 one (which has i think 30% more flow stock)

RB20/RB30 heads are almost the same in terms of flow.

Cheaper to drop an RB30ET in there than waste money, time and effort putting an RB20 head on it for absolutely no performance gain

[blackrb20silvia]

i actually thought the reason why you dont use the 20 head is that the galleries dont line up as the head design are completly different

am i wrong

[DRIFTER]

the reason i want to do this is i don't want to change my injectors or wiring, i am happy with my power i just want more response for drift.

p.s. i have been quoted $600 for a 53mm koyo radiator, are they any good, a pwr 57mm is $800 are they worth the extra money, at the moment i get 2 laps of drift before the temp reaches 100.

[Cubes]

Don't waste your time with the dohc rb20 head on the 3ltr.

It will feel like a diesel to drive, not fun.

If you don't know how a turbo diesel feels take a patrol 3.0tdi for a drive, its a good indication of how it will feel. Lots of mid range, it will rev but not make power.

Grab a 32 rb25 head, they look exactly the same as the rb20, plenum and all.

Edited November 2, 2005 by Cubes

[FATAZZ]

bit off track but, can you run boost through a rb25de head on a rb30N/A block safely?

[Cubes]

Why wouldn't you be able to?

Have a read of the RB30 thread.

[FATAZZ]

will do,cheers!

[R31Nismoid]

the reason i want to do this is i don't want to change my injectors or wiring, i am happy with my power i just want more response for drift.

but you wont get that!!!!

[DRIFTER]

but you wont get that!!!! 

       

<{POST_SNAPBACK}>

what is the technical reason why i won't get that

[DRIFTER]

if an rb 20 can flow 280rwkw, then i figure the head is not going to start restricting airflow just because it has a 3ltre bottom end.

[Dahtone Racing]

it can flow 280 with the standard displacment but your gonna be adding a litre of extra displacment there fore a shitload more flow is going to be needed

just get and RB25DE head from and R32 and you can use your injectors and shit

[R31Nismoid]

what is the technical reason why i won't get that

which reason ive given you in the past do you want me to quote?

[DRIFTER]

which reason ive given you in the past do you want me to quote?

<{POST_SNAPBACK}>

one that isn't just a theory but has some experience to back it up, has anyone actually done it and can tell me how it went?

[Cubes]

Try it let us know how you go.

You have been told its a crap setup and will not rev nicely.

The RB25 head flows much much better than the rb20det head.

I picked up 12rwkw with 6psi less boost.

Japanesemotor sport has a blown rb25det motor available for $900.

Edited November 5, 2005 by Cubes