R33 Rb30 Conversion

[Cubes]

Sydneykid made a little table some time ago.

http://www.skylinesaustralia.com/forums/in...t&p=2201542

I was a little skeptical of his recommendation for the R32 RB25DE head but closed my eye's blocked off the rear and installed a 1.5mm restrictor up front. Works exceptionally well; still plenty of oil flicking around in the head; never does it start to fill past the buckets like std restrictors do.

Before the restrictor and blocked rear oil would pool around the buckets on idle; after a hard 6000rpm+ run there was noticeable filling within the cam covers. On idle the oil level would drop to ~1/4 up from the low.

After the restrictor mod on idle the oil level sits up around the 3/4 mark so lots more oil sitting in the sump where it should be.

Preventing surge is the real reason for the mod not because you fill the catch can. I never had oil floating around apart from once when rev's were held at 6000rpm+ for an extended period of time. I removed the oil filler and could oil half way up the base circle. :S Very dangerous.

So BAM33; becareful if you take it around your local track or hold high rev's. Overfill the sump to prevent surge.

Do remember R33 Rb25DET's run 2 x 1.5mm restrictors standard where as the RB30's run 1.8's. So combine that with a high pressure pump and its not a good thing.

---

I built my motor right near the beginning of this thread when JUN collars were $600+ and little talk of it being essential. I have kept the rev limit @ 7000rpm and with an RB25/GTR pump (same thing) nothings broke YET. Its done *ouch* 68,000km's. :S

Bores still look excellent; compression is still spot on as it was once it was run in. No blowby in to the catch cans (I run one either side).

[Dahtone Racing]

**oops i better learn to read**

Edited September 3, 2007 by 2GU UP

[CEF11E]

wow so there are a few getting round with standard RB30 oil pumps.

looking at the design there are a different number of teeth and looks like the RB20 pump wpold provide more flow and pressure.

I have read the twincam head needs more flow but we all seem to be blocking off some of the flow to the head.

is it possible using an RB30 pump and no restrictor modifications would be acceptable for a street driven engine that rarely sees 7000 rpm?

[Cubes]

The RB30 SOHC's with the turbo pump still have issues with a little too much oil in the head at high rev's (7000rpm).

[ill_lh]

Hey guys, just doing some searching.....

found a place called Port City in victoria will build you a RACE rb30 engine to coincide with the rb25 head for $3500, whuch includes:

- chemically cleaned block

- crack tested

- deck machined

- bored and honed

- cam bearings

- hyperutectic or forged pistons

- crank tested, balanced and polished

- preped rods arp rod bolts

- moly rings

- ultrasonic thick the block

- torque plate hone bores and 600g finish

- all new race spec big ends, cam bearings, thrust washers, brass welsh plugs, full gasket set.

All fitted, as this is what im getting done i just need to find a rb25 head....

of course if its not a race engine your after they have kits ranging from kit a - kit d, this one is kit d, so the others are cheaper. kit B would be perfect for a street rb30 and this kit is 1800 + fitting which is about 350.

so really its not as dear as everyone thinks, plus this is done by a shop, not me, it would cost me MORE to do it myself...

there number is (03) 5523 6968 there in portland, victoria.

i live in brissie and it cost $150 for freight there too.....

[CEF11E]

I had a productine evening last night.

I built a tool for removing and refitting valves in RB heads after ordering 2 that did not fit. i built it from pics cubes and secur1ty had put up here.

the tool worked perfectly and I have now got the valves, guides, springs, retainers and collets in the head. I think I am going to do the lifters in the oil and squeeze them before assembling the head as it has been apart for a month.

I also made up the VCT supply line. all the parts I got from Aushose (like pirtek) I used the following

male to male 1/8 NPT to 1/8 BSP adapter from the oil pressure hile in the block

female/female/female 1/8 BSP T peice

nipple with compression olive 1/8

hose from side of block to head

nipple with compression olive tapped into the VCT gallery.

the whole shebang only set me back $40 I thought it was going to be $150

having said that the supply line is nylon. it is rated at 250deg and 250psi. I think I am going to replace it with copper.

the engine should be finished on the weekend. cant put it in till after Texikhana but it should be in and finished in a month

[BAMR33]

Cheers for that great information, now I'll just take a shopping list into pirtek rather than trying to explain to them what I need .

You could use bundy tubing for the feed line too.

Edited September 7, 2007 by BAMR33

[Cubes]

Bundy tube FTW!

The stuff is easy as to bend and get it exactly where you want it. Its also cheap as chips.

[Scooby]

only with the engine out though - if yer usin' twins. after my turbo fiasco and having to remove them because one of the 'çertified good' ones went to lunch permanently i went to braided. admittedly i'm using long waste gate dumps ie trust style and that complicated things but there was no way those bundy numbers were going back in the same place.

mind you i was not compromising about keeping constant radius and that contributed.

Edited September 7, 2007 by Scooby

[TiTAN]

Hi,

I am starting my 25/30 conversion shortly (Currently have the series 2 VL RB30 NA motor and an R33 RB25 head)

I was just wondering with the turbo i want to go with (Garrett GT3540R looking for 350-370kw @ the rears). Would it make much difference going to an internal wastegate version over an external wastegate setup? The car will mainly be used as my daily driver with a few track days every now and then.

Cheers.

[r33_racer]

go whichever way you want...though i dont know if peole are having many issues with boost control with internal gates yet... obviously an internal gate would prove easier and cheaper with no need for an ext gate and aftermarket manifold.

[CEF11E]

I finished building my 25/30 today.

I had a couple of issues.

I used the twin tensioner using the standard tapped threads (both low) and using the 149 teeth dayco belt there is to much tension. i am going to have to go the 150 teeth belt. this is the same issue others have had with both tensioners low using the 149 tooth belt.

I am going to try to fit it again tomorrow but the preload required to get the 2nd tensioner on seems to high. i will let you all know how it pans out.

apart from that the engine is ready to be fitted to the car.

[Dahtone Racing]

i fixed my issues with the belt

its perfect now, with a bit of f*king around you can get it right

[Cubes]

What did you end up doing?

The only real problem was it felt too tight getting it on or?

[Dahtone Racing]

it was tight as shit to get on

but once it was on and we loosened the tensioners it sat nicely

tightened everything up and shes perfect

[fatz]

mine is running now

http://s14.photobucket.com/albums/a304/low...nt=07092007.flv

[[200]]

Nice sleeper...

A question re Power FC's.

I am looking at buying one soon for my 26/30 build up for an S15. Do I get a power FC to suit an S15 or a GTR?

[linedup33]

im pretty sure wat ever head u have on the engine get the ecu to match that, so in ur case u would need one to suit the 26 gtr.

[GTRgeoff]

Wrong.

The best choice is the one that suits your car (unless you have a 19th century technology R31 or earlier). Then you work around that. I have the 26/30 in the GTS25t with 26 plenum and throttles and TT's and run it all with the 25t PFC, and the only sensor changes were the z32 and the water temp sensor since the 26 sensor maxes the temp signal. Even as a TT I have it set up for single AFM. I also have a single O2 sensor at the split pipe join.

If you have to use twin AFM's then you can wire it to supply an average input from the sensors.

PS, Fatz you are a massive shoebox torturing wanker

Have you no pity on that ancient barge???????

[fatz]

PS, Fatz you are a massive shoebox torturing wanker

Have you no pity on that ancient barge???????

think inside the box!

3 litres of GTR love is what every 31 wants!!!!!!!!!!!!!!

and if it want more i still have NOS!