R33 Rb30 Conversion

[Spoolup]

Here are the pics for the water gallery mod. Some people dont do it but I dont like to rely on the thin bit of gasket to seal.

So pic 1 shows the std RB25 head, Pic 2 shows the std RB25 head with a RB30 gasket fitted, and Pic 3 shows that the RB30 gasket just covers the water gallery in the RB25 head by a few mm ( see the black Nikko Pen line )

I have the hole welded up ( and the oil gallery hole ) and reshaped to the same size as the RB30 hole so that the gasket fits perfectly.

Edited April 17, 2008 by Spoolup

[bluegts]

OMG!!!!! LEGEND

Finally somebody who understands what I was trying to get at, and hopefully now people can understand that I wasn't asking a repeatadly asked question about VCT.

Cheers mate, that's helped alot!

Jack

[Cubes]

aaaannnnddd a snip from the rb30det guide if u looked at it like I said.

shows the same thing side by side. You can see where the differences are and what needs to be modified.

[Craved]

i remember reading somewhere about what bluegts is asking - someone welded steel onto the Block arounda water gallery then had it decked - apparantly there was only a small amount of overlap between the water gallery and the edge of the block..

OMG!!!!! LEGEND

Finally somebody who understands what I was trying to get at, and hopefully now people can understand that I wasn't asking a repeatadly asked question about VCT.

Cheers mate, that's helped alot!

Jack

As im using the rb25 gasket i'll prob be doing to the opposite of what spoolup has shown

[Alf]

Does anyone know if there is an "off the shelf" MLS headgasket thicker than 0.074 (1.9mm) for a RB30 or RB26?

ACL, Nengun and Greenline's thickest are 0.051 (1.3mm), Cometic make a 0.074 for the RB30ET ( will suit my mod'd 25 head).

Trying to get the comp down to 9:1

Last resort is to go custom.

Edited April 18, 2008 by Alf

[Adriano]

I would measure the crown thickness, and be very tempted to machine some of the crown off, its a cheap job on a lathe, and will get you away from the horrid squish you are going to encounter with a "decompression plate". PS you can run 2 gaskets.

[GTRNUR]

Tomei make a 2mm head gasket with an 87mm bore. Nengun or high octane perhaps?

[bluegts]

aaaannnnddd a snip from the rb30det guide if u looked at it like I said.

shows the same thing side by side. You can see where the differences are and what needs to be modified.

Yeah I've read your guide so many times its not funny, but it didn't mention anything about reshaping the water gallery thats why I got confused. It states 'how they need to be modified' and I just assumed that was refering to the mod required to block the VCT oil feed. Cheers anyway, I'm all good now

Jack

[R34NRG]

hows it going guys.

cars finally doing the final tune, but we are having massive boost isssues.

the car is making over 300rwkw at 4000rpm but just cannot hold boost. set boost off so it runs off the gate (.9 bar) and it just keeps climbing.

heres the current setup

3.0L

gt3540 .82 housing

44mm tial gate with .9bar spring

exhaust 3.5" to cat then 3" all the way

ive started a thread in the main FI area. any help in here is greately appreciated aswell.

http://www.skylinesaustralia.com/forums/Hu...ep-t215455.html

44mm gate is big enough right?

we are currently in the mist of dc the gate to find out if it will make any boost. if it dosnt then the gate is fine.

some ppl think it might be the dump pipe being to big? (3.5" to cat then 3" all the way)

lastly it might be a faulty manifold?

any help appreciated

Edited April 18, 2008 by R34NRG

[MBS206]

Random thing to try...

T-Piece a boost gauge in JUST before the pressure line enters the wastegate.

See what boost it's seeing down there.

Waste gate may not be connected properly pressure source wise.

Now for my question...

I have an RB30DET in my car.

Had some issues getting it to crank.

Had to pull timing belt off etc. Check to make sure cams would turn etc...

Stupidly, I made ZERO markings, and now need to know, HOW do I get the timing belt back on in the right position now that I have everything sorted out.

I know I need to pull the harmonic balancer back off and have a good look down there... BUT, how can I get the timing belt back on correctly, since everything has been spun independant of other things?

[MBS206]

Subscribing.

[GTRgeoff]

Matt, just make sure your timing marks on the cam gears and the cam drive gear are aligned properly. There is a notch in the oil pump housing for alignment of the drive and marks on the outside of the cam gear backing plate to align the cams. Get them aligned, slip the cam belt on keeping the right side as you look at it tight then adjust the tension. Check again that all the alignment marks are properly lined up and then wind over the engine 2 turn clockwise as you look at it by hand and check again, then if all is aligned properly re-tension the cam belt.

[MBS206]

Geoff! AWESOME MAN!

That's a huge help.

WIll be going down soon to attack it.

Hopfully have it all back together tonight...

[20sil]

Hey, first post here. I currently own an SR20, yes very torquey engine and i love it.. when its reliable (drifting). I had ideas floating around about 1j's, 25's blah blah but then a mate got me onto this idea of the 30/25 setup, i liked it so much that im picking up and engine this week. Im up to page 55 in this thread (2 tabs open) and i plan on going through the whole lot. What i want to know for now just to get more of an idea is where the RB30DET guide that Cubes i think has made? If someone could lead me to that id be much appreciative. Also after reading 55 pages the thing im still stuck on is whether to keep VCT and what CR are best? I can get my hands on a RB25DET head complete for relatively cheap to..

[Adriano]

There is a link in his signature, just persevere and keep reading

[MBS206]

Hey, first post here. I currently own an SR20, yes very torquey engine and i love it.. when its reliable (drifting). I had ideas floating around about 1j's, 25's blah blah but then a mate got me onto this idea of the 30/25 setup, i liked it so much that im picking up and engine this week. Im up to page 55 in this thread (2 tabs open) and i plan on going through the whole lot. What i want to know for now just to get more of an idea is where the RB30DET guide that Cubes i think has made? If someone could lead me to that id be much appreciative. Also after reading 55 pages the thing im still stuck on is whether to keep VCT and what CR are best? I can get my hands on a RB25DET head complete for relatively cheap to..

Go to the very first post in the thread.

There's a link at the bottom of the first post.

Open it. Then there's al ink to the DOHC guide.

Also read Cobra's

[RB120WHY]

Just a bit of custom work i'm really happy with

[GTRgeoff]

Should I feel atrocisized?

Nice looking job though but isn't it spelt 120Why?

[RB120WHY]

Should I feel atrocisized?

Nice looking job though but isn't it spelt 120Why?

haha yeah, but i ran out of room

[Al]

I have never seen anyone post up a torque comparison so here is mine

Same dyno, same tuner.