John M

Ok so I bought a block for my GTT neo. It was sold to me as a "rb25det neo" and then come to find out its AWD. i thought i would just have to adapt the oil pan and pick up but now its got me worried. I read that the GT-4 and GTT blocks are very different, like the pistons, rods, oil squirters (lack of) are different. can anyone help? what kinds of AWD blocks are there for the RB25, i know this one had the transfer case on the oil pan. -thanks, John heres pics of the new block

I need a complete assembled head, including cams & gears. Price? do you still have fuel rail, if so, price? Im located in the USA, raleigh nc 27614. -John

Cylinder Bore Size 87 Piston Stroke Length 73.7 Head Gasket Bore Diameter 88
 Compressed Head Gasket Thickness 1.2
 Combustion Chamber Volume In CCs 51.5
 Piston Dome Volume In CCs Negative For Dished Pistons (Use '-') 15.5
 Piston Deck Clearance Negative If ABOVE Deck (Use '-') : -0.5715 (when using 87mm rb26 8.5:1 cp piston with Compression height of 1.193) right now its at 11.9:1 I think im pretty much screwed on the Neo head + RB26 crank & piston combo. I thnk ill have to either A. sell the neo head and go for the larger CC standard rb25 head B. sell the whole built short block and get a bone stock neo bottom end and throw my neo head on it. Opinions? help? -Thx

Hello, Ive got an R34 RB25DET Neo motor, i put an R33 RB26DETT Crank & rods in it, and need help with piston selection. The neo head has a CC of 51.5 which is smaller than the standard rb25, and way smaller than the rb26. I bought rb26 pistons (87mm bore which my block has been bored out to) and after installing them, did compression ratio calculations and am getting something around 11:1. Just wondering if anyone has some insight on this! Thanks guys, John m Raleigh, North carolina, USA (S14 RB25 Neo)

I assure you that i know it is physically different or else i wouldnt be in this dilemma of selling the head. I picked up the newly machined head from the machine shop with a bill totalling $498. I went to put the head on and realized it is not the correct head. The intake manifold ports are very different and the overall diameter of the ports is a lot narrower than my previous head. The intake manifold from the R34 DET neo will not bolt onto the head ORIGNAL NEO HEAD (R34 GTT RB25DET NEO) 2nd Head The DET ports are a LOT bigger than the DE ports although it may not seem to be so from the picture. The overall diameter is larger, even though it looks like it bottle-necks on the DET. The CC's inside the head are far smaller than the DET which would result in different CR. Also, the neo DET cams push the valves too far out into the combustion chamber and i believe that the valve timing would overlap if the head was used with the Tomei cams for the DET neo. the machine shop would olny fully instal the exhaust cam, and left the intake cam cams evenly loose to allow the lobes to not depress the lifters which would result in the intake valves hitting the exhaust valves when rotating the cams to set the timing when the pistons are at TDC. -John

I bought this head for $320 USD for my R34 GTT thinking it was a DET neo head. It was purchased from a gentleman in okinawa japan and i had it shipped to the US. I had the head machined to the proper specifications, with the following performed: -Clean -Pressure Check -Valve Job -Solid Lifter Adjust -Re-surfaced Which totalled to $498 USD. Now, i have no use for this head, and have invested over $850 USD into it. I am just trying to get back some of the money so that i can re-purchase the proper head. If anyone is interested, Please send me an email, or PM. I need to move this head asap. Thank you all for looking. I will post pictures up within a few days when i can. -John M [email protected]

hey man, for an R34 RB25DET NEO motor, the valve clearances are: Hot engine Intake: 0.36 +/- 0.062 (mm) Exhaust: 0.53 +/- 0.062 (mm) Cold engine (at ambient temperature) Intake: 0.31 +/- 0.04 (mm) Exhaust 0.50 +/- 0.04 (mm) Hope this helps. let me know if you need anything else. -John

Would you be willing to part with the head? -John

hello, im searching for a replacement head for my 1998 R34 GTT (RB25DET Neo motor). If anyone has one, or knows where i can find one, please let me know as i need this asap! thanks a lot. -John

Hello, I just joined this forum, and need some ones help tuning my power FC. Im located in the U.S. I have ordered a Datalogit and want to see if someone would be willing to help me set up a decent map, or at least get me started. I've got an S14 with 98 R34 GTT RB25DET Neo motor running on a base map. I just recently bought the car and the previous owner did not set the timing right so the motor is getting a full look over. there is some valve tick and the head will be pulled off and sent to a machine shop to get re-done. after i get it all back together, i would like someone to help me tune it by me sending a datalog, and getting a Ign/Inj map back. here is a little more about the car. Motor (~2,500 Miles on it) Neo RB25DET out of a '98 R34 GT-T (essentially a built RB26 bottom end w/ a Neo RB25 head.) Block/Head cleaned and milled to spec, valves adjusted (Revolutionary Performance (RPM) in Mt. Juliet) RB26 (R33) GTR Crank w/ longer oil pump drive RB26 8.5:1 CP Forged Pistons RB26 Forged Rods ARP Fasteners ACL Bearings Cometic 1.1mm MLS Metal Head Gasket Greddy Intake Manifold (Modified stock Fuel Rail to seat injectors properly) Greddy Timing Belt Greddy Oil Catch Can OEM Infinity Q45 Throttle Body OEM Nissan Z32 Throttle Position Sensor OEM Nissan Timing Belt Tensioner OEM Nissan Timing Belt Idler Pulley OEM Nissan Water Pump OEM Nissan Thermostat OEM Nissan Intake Manifold Gasket OEM Nissan Exhaust Manifold Gasket OEM Nissan Valve Cover Gaskets OEM Nissan 91’ Sentra IACV OEM Nissan N1 Oil pump -10AN Head to sump Oil Return Line Air Conditioning Delete Engine/Trans Mounts Syko Performance motor mount kit OEM Skyline R33 Cross-member Automatic S14 Transmission x-member Peak Performance Pro Transmission Mount Transmission / Drive-train R34 RB25 Pull style clutch Sprung 6 puck Kevlar clutch disc (from Tennessee Clutch & Supply) OEM Resurfaced Pressure Plate OEM Resurfaced Flywheel One Piece Aluminum driveshaft. Stock Open Differential Fuel Walbro 255lph fuel pump Nismo Fuel Pressure Regulator OEM Nissan Z32 TT Fuel Filter Turbo/Exhaust Factory RB25 T28 turbo, factory exhaust manifold HKS BOV (SSQV - new version) Syko Performance 3" Stainless Steel Turbo Elbow Blitz SR20 3" Stainless Steel Downpipe Resonated 3" Stainless Steel Test Pipe Apexi N1 3" Dual Cat-back Exhaust Cooling Griffin Aluminum Radiator Flex-a-Lite Dual 12" Pusher E-fans w/ thermostatic relay Hybrid FMIC, 3" inlet, 3" outlet (custom piping) Apexi Power Intake Suspension Megan Racing 32-way adj. Street Edition Coil-overs Battle Version Rear Upper Control Arms Brakes Z32 TT Front Brakes Z32 TT Front Caliper Conversion lines Z32 TT Front Slotted rotors Wheels Forged RAYS Engineering 350z Track Edition wheels (F) 18x8 +33 (Bridgestone Potenza RE 960AS Pole Position 225/45/18) ® 18x8.5 +30 (Nankang NS-II tires 255-35) Electronics / EMS CARL H approved engine harness and gauge cluster calibrated to read correctly ER34 Apexi Power-FC Standalone EMS w/ Hand Commander AEM Tru Boost Gauge/Controller AEM Uego Wideband Summit Battery Trunk Relocation Kit (0/1 Ga. Kit) OEM Nissan Quest Alternator (140amp) I have also started sort of a build thread on the NicoClub forum. you are welcome to check it out and let me know what you think. Thanks, John