MC-WOSHY Posted April 25, 2015 Share Posted April 25, 2015 Hey guys, I have a S1 R33 with a S1 RB25DET. Recently I did a compression test on it and it says low on compression. So I bought another 25 head which I plan to swap over. However upon taking it to a Head Shop today, they have stated the head may be a NEO 25. On the exhaust side of this head it says 5L83 and I'm just wondering if anyone can confirm this is indeed a NEO? Also, is this going to now not be compatible with my S1 RB25 block? Just because this new head is straight and in good condition. Cheers for any help! Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/ Share on other sites More sharing options...
Ben C34 Posted April 25, 2015 Share Posted April 25, 2015 Put up some pics. If it is a neo head your compression will be too high. Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522484 Share on other sites More sharing options...
MC-WOSHY Posted April 25, 2015 Author Share Posted April 25, 2015 This is the only photo I have unfortunately as the head is at the head shop now -_- probably not gonna help Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522487 Share on other sites More sharing options...
MC-WOSHY Posted April 25, 2015 Author Share Posted April 25, 2015 Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522493 Share on other sites More sharing options...
Ben C34 Posted April 25, 2015 Share Posted April 25, 2015 This is the only photo I have unfortunately as the head is at the head shop now -_- probably not gonna help You are correct. ... Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522598 Share on other sites More sharing options...
MC-WOSHY Posted April 25, 2015 Author Share Posted April 25, 2015 I think I may need to ring Nissan and give them the code, they should be able to tell me Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522599 Share on other sites More sharing options...
AngryRB Posted April 25, 2015 Share Posted April 25, 2015 (edited) a neo head uses a different cas, black cover on it, I'm after a neo and selling a S2 head with tomei cams , might be interested in a deal here Edited April 25, 2015 by AngryRB Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522626 Share on other sites More sharing options...
MC-WOSHY Posted April 25, 2015 Author Share Posted April 25, 2015 Oh ok, I just got the bare head as you see in the picture, didn't need the other stuff so I think I'm unable to tell Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522646 Share on other sites More sharing options...
Ben C34 Posted April 25, 2015 Share Posted April 25, 2015 Once you can get a pic of the timing gears from the front, or even the same shot you posted with nothing wrapping the head. Can tell easily from.that. Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522649 Share on other sites More sharing options...
AngryRB Posted April 25, 2015 Share Posted April 25, 2015 (edited) wouldn't it be easy to tell if its solid lifters or not ben?? they have smaller runners too don't they, wonder what the difference is there.... Edited April 25, 2015 by AngryRB Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522652 Share on other sites More sharing options...
MC-WOSHY Posted April 25, 2015 Author Share Posted April 25, 2015 Ok mate, will get that tomorrow! Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522654 Share on other sites More sharing options...
Ben C34 Posted April 25, 2015 Share Posted April 25, 2015 wouldn't it be easy to tell if its solid lifters or not ben?? they have smaller runners too don't they, wonder what the difference is there.... The runner size difference is minimal, unless its the na head, which is noticeably smaller. The lifters are pretty obvious but the vct allen head grub screw rather than bolts and lack of vct oil drain on the side of the head is obvious from a distance. 1 Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522658 Share on other sites More sharing options...
iruvyouskyrine Posted April 25, 2015 Share Posted April 25, 2015 That pic you posted is a neo head. Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522817 Share on other sites More sharing options...
sonicz Posted April 26, 2015 Share Posted April 26, 2015 Yup Doctor Neo Cortex has a pretty big head. Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522871 Share on other sites More sharing options...
xntrq Posted April 26, 2015 Share Posted April 26, 2015 Yes it is a NEO head. The coilpack bolts straight onto the head in the NEO as with the non NEO engines are mounted on a bracket which are then bolted on by 12mm bolts. Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522886 Share on other sites More sharing options...
MC-WOSHY Posted April 26, 2015 Author Share Posted April 26, 2015 Ok, cheers for that info guys! Next question is, is it going to fit on my S1 RB25 block? Without any issues? As I know the NEO has VCT etc Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522919 Share on other sites More sharing options...
scotty nm35 Posted April 26, 2015 Share Posted April 26, 2015 No, the compression will be way too high as has already been said above. Swap with Angry RB? Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522920 Share on other sites More sharing options...
MC-WOSHY Posted April 26, 2015 Author Share Posted April 26, 2015 Ah ok! That's fair enough and swapping might be the go! But I'm in WA and idk where he is Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7522921 Share on other sites More sharing options...
iruvyouskyrine Posted April 26, 2015 Share Posted April 26, 2015 Yes it is a NEO head. The coilpack bolts straight onto the head in the NEO as with the non NEO engines are mounted on a bracket which are then bolted on by 12mm bolts. Correct. This is how I was able to tell. Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7523099 Share on other sites More sharing options...
MC-WOSHY Posted April 28, 2015 Author Share Posted April 28, 2015 (edited) So I have some more photos, These help at all!? Just to be super duper positive it is in fact a NEO before I decide to sell it off or swap it Edited April 28, 2015 by MC-WOSHY Link to comment https://www.sau.com.au/forums/topic/456055-rb25det-head-query/#findComment-7524264 Share on other sites More sharing options...
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