Rb25Det S1 Head Onto N/a Neo Bottom End

[HGHOON]

hey, ive done some researching and can only really find people putting neo and s1-s2 heads on rb30- 25det bottom ends etc but havent found any info on puttin an s1 -s2 rb25 turbo head on a r34 neo natro asp bottom end, now people have said that cross matching the turbo blocks with the neo heads will create low compression ratios but if my rb25de neo has a CR of 10:1 it shouldnt drop the comp that much and thus having a nice CR and the strength of the neo bottom ends? also wanna know if the different piston design in the neo will interfere with the head/valves at all?

any info much appreciated

cheers dave

[WMDC35]

just leave the neo head on?

[Ben C34]

the neo has approx 10cc smaller chamber. find an online comp calculator and figure it out. At a wild gyes I would say you would get around 9:1 but it definitely seems pointless , can you explain what you plan to achieve with the engine?

[HGHOON]

sorry i didnt mention that i was turboing it, all my manifolds etc wont fit the neo na head(having smaller ports etc), i have the greddy style inlet and everything on an 25/30 in another car but have a gtr head for that now and wanna use the whole 25setup on this r34 gt4, cant just slip the 25/30 in cause of 4wd and would need adapter plates etc. im just tryin to use wat i have in the shed and wanted to make sure it was going to be all good before i rip both cars apart,

[discopotato03]

Probably more work than you want to do but if you can find a Neo Stag short motor and freshen that up it should work . The NA rods and pistons may not be up to turbo use .

[HGHOON]

yeah i saw a stag neo det and manual box for like 1800 or something like that on ebay was cheap but i dont have that money to spend at the moment and have all this shit to use anyway, i'm not to concerned about the n/a bottom end it should be up to the task, they getting 500hp on stock bottom end neo det and de's use same gtr rods and pistons are a little thicker on top and made of same shit as turbo pistons, just hoping the CR is round 9:1 that way it should in theory be very close to det spec

[GTSBoy]

Oil squirters is a significant difference. Piston cooling not as good on NA and therefore a bit more prone to detonation.

[Ben C34]

Its an odd combo so I doubt you will find that anyone else had done it. Seeing as you have the stuff already I would do it, can't be too bad!

[HGHOON]

yeah i dont think the squirters are gunna be an issue as im not going for all out power but having a thicker crown on the n/a piston would be more prone the heat soak but again shouldnt be a real issue on mild power figures i'll have a crack at it!