Rb30Neo Compression

[Huzqld]

Hey guys, Building my rb30NEo and did some measuring and calculations today and came up with the following

Bore- 3.408"

Stroke- 85mm

H/gasket thickness- .051"

deck height- .008"

piston volume- 9cc

head chamber volume- 53cc

We came up with a comp of 8.16:1. Is this abit low these days? Will be running 98 and later E85 at track.

We are going to go with a .001 deck height and worked out to get somewhere like a 8.6:1 ratio we need to take the head down to 49-48cc, hoping to do this by milling the head down to get that value.

Any thoughts on whether this will be possible? The machine shop will give it a go by just milling a bit and cc'ing as they go.

But not entirely sure if we will get enough out of it or any other side effects

Cheers

Ian

[Huzqld]

**

Just found that cometic do a .030 head gasket..

So if I got them to deck the block to .001. and take the head to 50cc

Should get a ratio of 8.88:1

[Ben C34]

What pistons are they?

8.16 is quite low.

[Huzqld]

They are a wiseco piston

I was thinking somewhere in the high 8s would be ideal?

[KiwiRS4T]

9.5:1 would be better. You want different pistons.

[Huzqld]

From what I can workout, If i got .020" taken off the head and used a .030" gasket I would end up with 8.88:1

You are right. Different pistons would probably be ideal. Ive just had all this balanced... So if i dont have to it would be nice.

[Ben C34]

I would go with what you have got.

[iruvyouskyrine]

Current Pistons and more boost.

[Huzqld]

Anyone have any idea with the above deck height- head skim/ gasket combo if I Am likely to run into any piston/valve clearance issues

[Piggaz]

You'd want to be running some crazy lift pistons to worry about that considering you have dished pistons with valve relief.

What are your cams?

[Huzqld]

Cheers mate. Standard cams to start with. Not sure what it go to. Want to keep vct though

[GunmetaL]

Mine runs 9.3:1 with Neo head and stock Pistons

[Ben C34]

The pistons op are using are not stock.