Hybrid 25/30 Neo R34

[GTRsean]

just curious because my mate has just got hold of a 30 block and wants to put it in his r34... but has heard that the neo head is not a good option because of the shim and bucket set up inside the head(aluminum intake buckets).

[Adriano]

Doing one at the moment, i feel they are definately superior to the r33 head fr that reason. Ive fitted gtr cams. You just have to cc the head, as the bowls are much smaller than the r33 head, so you end up using rb30et turbo pistons and end up with mid 8's comp.

[GTRsean]

He's sourced a good bottom end, and thats at the machine shop.

At the moment he's aiming for around 600hp at the crank.

Still deciding on turbo.

RB30E block

Stock crank prepped, balanced etc.

stock rods(na RB30)

ACL bearings

RB26 ARIAS pistons 86.5mm

total seal rings

Head R34 neo RB25

plazma man intake manifold

tomei 260 poncams

70 hp nos system

[r33_racer]

Brad...Spool imports has a neo head on his 25/30. It has and can be done.

[R31Nismoid]

Yer, im pretty sure the pro/con is covered in "the" thread

[FSTR32]

Yer, im pretty sure the pro/con is covered in "the" thread

care to share where "the" thread might be located NISMOID???

[R31Nismoid]

Look up and live.

There is a sticky thread about 25/30 conversions.

Been around since 2004. If you havent seen it by now, then dont complain.

[Spoolup]

email me for any info you require.

The RB26 pistons will give very high comp ratio due to the R34's small combustion chamber.

They are not an option really.

[ovabooster]

im also thinking about using my neo head....because they have smaller combustion chamber means that the comp ratio will be higher then that off a r33? I need alittle help in finding the right pistions to give the best comp ration...Will be using t04z and pushing 2.2 bar max...I would still use my hks gasket 1.2mm...

cheers

[ovabooster]

bump?

[Adriano]

Whats the question? rb30 pistons wont cut it, the comp ends up too high. If you plan on using a 1.2m headgasket to drop it, it wont be anywhere enough, and is the wrong way of going about it. RB30ET forged pistons work out about right in the comp, at between 8.3 and 8.6 depending on what headgasket you use, how much the head/block get skimmed during the build, and the specific brand of piston.

[ovabooster]

what cams would best be suited? I already got poncams 260 with valve springs..Should i sell them and get bigger ones? t04z with 1.x a/r

cheers

[GTRsean]

email me for any info you require.

The RB26 pistons will give very high comp ratio due to the R34's small combustion chamber.

They are not an option really.

Yep, he ain't using those pistons anymore, as they are wrong for the job......