045HOW Posted July 11, 2011 Share Posted July 11, 2011 Hey guys i have a series 2 RB25DET with a cracked ringland and cylinder scoring in cyl 6. Head is all ready and prepped,so now i just need a new bottom end. looking at a neo engine to use. are the bottom ends the same? Will a series 2 head go on with no dramas or is it best idea to just convert to the whole neo? Excuse my nubness on this matter. Cheers in advance. Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/ Share on other sites More sharing options...
GTSBoy Posted July 11, 2011 Share Posted July 11, 2011 Bottom ends are not the same. Neo chamber is different size, so Neo block got different pistons to give the right compression. non-Neo head on Neo bottom end would be a really poor choice. Sell your head, buy complete Neo. cheers Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5907396 Share on other sites More sharing options...
045HOW Posted July 11, 2011 Author Share Posted July 11, 2011 (edited) Thanks mate If i were to put a neo in my 33 what complications would i run into? I would be using my series 2 RB25DET manual box. would the ecu run the r33 dash and everything else? Or am i able to use my series 2 loom and ecu? Edited July 11, 2011 by Blueone Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5907409 Share on other sites More sharing options...
GTSBoy Posted July 11, 2011 Share Posted July 11, 2011 You need the Neo's ECU to run the engine. I know nothing about S2 dashes (is there anything strange in there that relies on somethign special from the ECU? I expect not.) but would not expect any huge hassles. Tacho outputs are simple. Your gearbox will work fine. You may well need to rewire a number of plugs on the engine loom (I have to for Neo into my R32 - but they may be the same between R33s and R34s, I just don't know). Find a workshop who has done it before and it should be trivial - unless you want to do it all yourself. Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5907762 Share on other sites More sharing options...
Adriano Posted July 11, 2011 Share Posted July 11, 2011 If yours is a late series 2 with the palstic cam angle sensor then the motor should go straight in. May need to change the injector plugs Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5907890 Share on other sites More sharing options...
045HOW Posted July 11, 2011 Author Share Posted July 11, 2011 If yours is a late series 2 with the palstic cam angle sensor then the motor should go straight in. May need to change the injector plugs Nah its a December 95 series 1.5. So,close to one of the youngest series 2 engines. Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5907906 Share on other sites More sharing options...
XRATED Posted July 11, 2011 Share Posted July 11, 2011 dirty 30 time... Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5908298 Share on other sites More sharing options...
045HOW Posted July 11, 2011 Author Share Posted July 11, 2011 dirty 30 time... I wish!, and i will! But now is not the time Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5908311 Share on other sites More sharing options...
XRATED Posted July 11, 2011 Share Posted July 11, 2011 then pop a 1k wrecker s1/2 rb25 inthere and use the good head for the 30 build... Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5908500 Share on other sites More sharing options...
045HOW Posted July 11, 2011 Author Share Posted July 11, 2011 (edited) then pop a 1k wrecker s1/2 rb25 inthere and use the good head for the 30 build... 1k you reckon? Hmmm. Would be a good idea but no 30DETT i have built will have a 25 head or a big single Edited July 11, 2011 by Blueone Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5908517 Share on other sites More sharing options...
Simon-S14 Posted July 11, 2011 Share Posted July 11, 2011 yuo can adapt the R33 loom to run the Neo. Roll's did a similar thing. all the RB;s from 20/25/26 can be adapted to run any RB loom. just takes some work and swapping of sensors and plugs to match the ECU. idealy tho.. use the neo loom and neo ECu and then get a nistune on the 34 ECU... win Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5908542 Share on other sites More sharing options...
discopotato03 Posted July 11, 2011 Share Posted July 11, 2011 I'd be looking through aftermarket piston catalogs to find out what the dish volume is like compared to an R33 RB25DETs and if they are same or very similar go for it . If all your R33s sensors interchange in the R34 block I don't see negatives , the positives are younger and potentially fresher pistons/rings/bearings depending on mileage . As was suggested a cheap RB30 with fresh rings bearings and a hone could be cheaper again , just need some welding on the heads face and its off anyway . Done carefully it may not cost much more than a "runner" RB25 . A . Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5908889 Share on other sites More sharing options...
Rolls Posted July 12, 2011 Share Posted July 12, 2011 (edited) yuo can adapt the R33 loom to run the Neo. Roll's did a similar thing. actually an r32 with r32 loom, but yeah apart from that exactly as you said, just a few r33 bits thrown in. actually TPS was the only thing that had to be changed. Edited July 12, 2011 by Rolls Link to comment https://www.sau.com.au/forums/topic/370594-replace-s2-rb25det-bottom-end-with-neo-bottom-end/#findComment-5910765 Share on other sites More sharing options...
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