Huzqld Posted October 28, 2014 Share Posted October 28, 2014 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 Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/ Share on other sites More sharing options...
Huzqld Posted October 28, 2014 Author Share Posted October 28, 2014 ** 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 Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416032 Share on other sites More sharing options...
Ben C34 Posted October 28, 2014 Share Posted October 28, 2014 What pistons are they? 8.16 is quite low. Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416051 Share on other sites More sharing options...
Huzqld Posted October 28, 2014 Author Share Posted October 28, 2014 They are a wiseco piston I was thinking somewhere in the high 8s would be ideal? Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416070 Share on other sites More sharing options...
KiwiRS4T Posted October 28, 2014 Share Posted October 28, 2014 9.5:1 would be better. You want different pistons. Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416092 Share on other sites More sharing options...
Huzqld Posted October 28, 2014 Author Share Posted October 28, 2014 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. Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416118 Share on other sites More sharing options...
Ben C34 Posted October 28, 2014 Share Posted October 28, 2014 I would go with what you have got. Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416125 Share on other sites More sharing options...
iruvyouskyrine Posted October 29, 2014 Share Posted October 29, 2014 Current Pistons and more boost. Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416590 Share on other sites More sharing options...
Huzqld Posted October 29, 2014 Author Share Posted October 29, 2014 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 Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7416704 Share on other sites More sharing options...
Piggaz Posted October 31, 2014 Share Posted October 31, 2014 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? Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7417622 Share on other sites More sharing options...
Huzqld Posted October 31, 2014 Author Share Posted October 31, 2014 Cheers mate. Standard cams to start with. Not sure what it go to. Want to keep vct though Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7417928 Share on other sites More sharing options...
GunmetaL Posted November 6, 2014 Share Posted November 6, 2014 Mine runs 9.3:1 with Neo head and stock Pistons Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7421311 Share on other sites More sharing options...
Ben C34 Posted November 6, 2014 Share Posted November 6, 2014 The pistons op are using are not stock. Link to comment https://www.sau.com.au/forums/topic/450142-rb30neo-compression/#findComment-7421333 Share on other sites More sharing options...
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