R33 Rb30 Conversion

[Adriano]

Interesting.. Whats with the 2 lumps in front of each cam shaft on the cam belt then?

It was an N/A that I had a look at, I wouldn't have thought the turbo head would be any different.

??? The cas still bolts to the front of the exhaust cam, but it has a different spline

[Cubes]

yer not sure.. Maybe it was just the different designed cas or something. Not sure it was some time ago I looked at it.

[Spoolup]

As I am running R33 RB26 cams I have to use the R33 CAS.

Adriano is correct with the R34 GTT head having smaller combustion chambers - mine is running 8.5:1 with ACL forgies.

[Alf]

Are there any differences in the 26 and 30 headgaskets?

I have a VVT 25 head thats had the front right water jacket and oil gallery welded up and the water gallery shaped to suit the 30 block.

There appears to be more thicknesses available for off the shelf MLS headgaskets for the 26.

[Cubes]

26 and 30 head gaskets are the same.

[Craved]

is there any issues running the RB25 gasket with the rb25det head?

obviously the oil feed is different, and will be modified for VCT externally..

[Cubes]

is there any issues running the RB25 gasket with the rb25det head?

obviously the oil feed is different, and will be modified for VCT externally..

Nope. I'm running the Cometic RB25 head gasket on mine without issues (~40,000kms). The price difference between the rb25 and rb26 was considerable at the time. I got mine from memory for $150.

[Craved]

Nope. I'm running the Cometic RB25 head gasket on mine without issues. The price difference between the rb25 and rb26 was considerable at the time. I got mine from memory for $150.

i got mine cheap but not THAT cheap ...

the rb25 cometic im running on the rb25 in the car cost me $330

got some ACL piston rings, so its almost wash and build time prob 3 weeks

[Cubes]

The engine builder put me on to them and thats what he was able to get the rb25 two for (Bl4ck32 and I). The rb26 I remember was up near $400.

[Alf]

Thanks for that Cubes.

I've been looking at the cometic and ACL race series MLS gaskets, Prices ive got ranged from 210-350 for an RB30 MLS headgasket.

is there any issues running the RB25 gasket with the rb25det head?

Its not really an issue with a 33 25 VVT head that I've seen but there is a 1-2mm of sealing on a particular spot on the front right water jacket. That is when you use a 30 block.

Just to be on the safe side I tigged the water jacket and VVT gallery up in the head and shaped it to suit the water gallery in the 30 block. Theres a min. 5-6mm of sealing now.

It was a better option that trying to braze weld brass to the side of the block like in this pic.

http://www.users.bigpond.com/twinvl/blockmod2.jpg

[Craved]

i wont be welding up the head, an drilling it out, and replacing witha grub screw thats sealed, so incase i use the head again on an rb25 it will be usable

[Cubes]

Alf,

So what your saying is the head actually hangs over the edge of the block nd the water galley in the head comes damn close to the edge of the rb30 block. I've attached a pic of my unmolested block.

[Alf]

So what your saying is the head actually hangs over the edge of the block and the water galley in the head comes damn close to the edge of the rb30 block.

Thats right.

[r33_racer]

woah alf thats exactly what i did to ours. haha i wasnt too keen on brazing the extra thickness to the block either.

[w0g7oy]

I heard the Non turbo rb30 pistons have less rings or sumting like that.. and dont cope with boost very well...

wen i was gonna turbo my rb30e, i was being told that the compression had to be lowered a fair amount from 9.0:1 to around 7 or 8:1 to stop pinging and detonation...

Why is it ok for a hybrid motor to have higher compression ratios? wont it ping/knock its tits off??

Jimbo

[Adriano]

Whoever told you that didn't know what they are talking about

I heard the Non turbo rb30 pistons have less rings or sumting like that.. and dont cope with boost very well...

wen i was gonna turbo my rb30e, i was being told that the compression had to be lowered a fair amount from 9.0:1 to around 7 or 8:1 to stop pinging and detonation...

Why is it ok for a hybrid motor to have higher compression ratios? wont it ping/knock its tits off??

Jimbo

[mr_rbman]

I heard the Non turbo rb30 pistons have less rings or sumting like that.. and dont cope with boost very well...

wen i was gonna turbo my rb30e, i was being told that the compression had to be lowered a fair amount from 9.0:1 to around 7 or 8:1 to stop pinging and detonation...

Why is it ok for a hybrid motor to have higher compression ratios? wont it ping/knock its tits off??

Jimbo

putting the 25/26 head on actually lowers the compression!

[Cubes]

Why is it ok for a hybrid motor to have higher compression ratios? wont it ping/knock its tits off??

1. Because its a hybrid motor. Better designed head that allows you to get away with a little more static comp.

2. Its all in the tuning. Simply throw a stock rb30et ecu on an rb30e that has a turbo bolted on to the side of it and try to push 14psi through it and it will almost certainly detonate. So tuning tuning tuning.

[Roy]

So the guys running the R32 RB25DE heads. What sort of power are you guys putting through the inelt manifolds...has anyone gone to an aftermarket one and noticed an improvement in response/power

[Cubes]

So the guys running the R32 RB25DE heads. What sort of power are you guys putting through the inelt manifolds...has anyone gone to an aftermarket one and noticed an improvement in response/power

Hey fancy seeing you in these neck of the woods.

AM-Performance is about to drop an aftermarket plenum on his within the next week or two.

Sky30 pushed 312rwkw through his r32 rb25de head running the stock exh. manifold and stock inlet manifold/plenum.

Thats the highest I know of on the R32 RB20/25 style plenum.