Rb30 25 Neo Build

[lcxu105]

Hi all. First off I'm no expert in skyline engines. Now thats out of the way.

Block I'm using is a s2 block. Std crank spool h beam rods and arias -10.4cc forged pistons. Block will get the usual jobss done acid wash hot tank and bored 40th to 87mm. Will be decked to zero deck height. Will use a 1 mm head gasket and neo head. Head is currently in the car on 25 neo engine. Head has been ported with stage 1 pon cams. Flywheel is from extreme billet lighten flywheel. 6 puck sprung button clutch. Inlet will be a greedy copy manifold with 1000cc bosch injectors. Hot side is custom made hi mount manifold by myself in t3 form to a gtx3582r garrett ball bearing item. Fuel will flow via 2 bosch 044 pumps. Will start with bp98 fuel then change over to e85 later on. Nistune will control all the electronics. Spit fire coil packs will fire the good stuff.

If anyone has same sort of set up would appreciate input as to what power I should be able to expect.

[KiwiRS4T]

301 to 399 rwkw. Too many unknowns. Is it going to be fully balanced with a new harmonic balancer and revved to 9000+ or standard and limited to 7000? Build and tune all count for a lot. You may end up with a sky high compression ratio which will be a problem unless you have access to E85. Don't use Bosch pumps - get something more modern, quieter and E85 friendly.

[Ben C34]

Those pistons are vl turbo spec.

Have you already bought them?

If not look seriously at something with less or no dish to get the comp up. The days of low comp have been and gone.

If you already have them, no worries, boost it up!

[lcxu105]

Looks like boost up as I have them already. For 700 delivered not going to complain. Will deck the head and use as thin as possible gasket. Head is fitted with cams 256deg and 9.15mm lift. E85 is available easy access. Will be balanced annd haven't set a rev limit yet

[lcxu105]

Besides this engine is going into a lc torana witch is around 400+kgs lighter than a r34 skyline. Neos run 9 to 1 comp but are 2.5lt engine. This is a 3lt engine. Off boost shouldn't be too bad as the 30det's only run a mid 7 to 1 comp. Off boost in a vl they are fine.

[MJTru]

Soumds like you have it together mate. Keep up the great work. A video of when its done and running would be nice

[lcxu105]

If anyone has any advice for mods to the head or engine as a whole I'm all ears.

[KiwiRS4T]

There is actually an RB30 section above, Also read the RB30 Hybrid upgrade dyno results section to see what people have done to make power.

[XKLABA]

If 0 deck heights min HG thickness is 33thuo for clearance

I think the dish is a bit big can you machine them down 40-60thuo and then deck block to match

I run 14cc dome top with 0 deck hieght and 1.1mm HG with 63cc combustion chamber ( 26 head ) and have +/- 9.5:1 state CR

[lcxu105]

I can machine the pistons down 40th and take 40th off the head. 8.44 to 1 was working on 1mm hg. By doing pistons and head machine work will bump it up around 9 to 1. Have looked at the 30 hybrid pages and read verrious builds but not close to what I'm building. Haven't seen any other builds with neo head and gtx35

[Huzqld]

I've got the bulk of my engine together now

Rb30, Neo head,

Spool I beams

Wiseco 9cc dish pistons.

.051" gasket

Head studs main studs

Standard head and cams to start with but has springs and ti retainers

CPC plenum 6boost manifold gt35

6x LS2 coils

Running a .001 deck height and we had to deck the head down to 46cc ending up with high 8 comp.

I'm hoping to make around 400-450hp with the standard cams on 98 (auto)

[lcxu105]

Hi comp 8? Engine builder told me with -10.4cc pistons zero deck height and 1 mm hg and std neo head. Comp would be 8.44 to 1. So if you are running +9cc pistons and head shaved down you would have more like 9 to 1

[KiwiRS4T]

Huzqld you should easy make the 450hp with a good tune, the right fuelling and at least 3in exhaust.

[lcxu105]

Huzqld you're comp ratio will be a high 9.6 to 1. Mine with a .51 hg and 50cc head wwill be 8.96 to 1.

[KiwiRS4T]

9.6:1 would be great.

[Huzqld]

Hey lcxu105

I think you may have messed up there with your gasket thickness. Because you're using mm but you are using inches measurement for the gasket. The gasket should be 1.295mm

Using the calculator above. mine comes out to be about 8.94:1

using the summit racing calculator (which allows to you to change hg to inches or mm) I get 8.98: 1

Mind you I could be wrong

Edited December 13, 2014 by Huzqld

[XKLABA]

Huzqld you're comp ratio will be a high 9.6 to 1. Mine with a .51 hg and 50cc head wwill be 8.96 to 1.

you have to put the HG thickness in in MM on that scale setup, so you have put in .51mm not 51thou which is closer to 1.3mm

Edit, should have read the whole page before posting lol, Husqld beat me to it

[iruvyouskyrine]

9.6:1 would be great.

Pretty much this.

[lcxu105]

Ok thanks for that.

[lcxu105]

Tracked down a .7mm hg so now all I need to do is shave the head to have 47 to 48cc chambers and im back up to around the 9 to 1 comp.