Out of towner with new engine build

[RalfMurphy]

Hey SAU

I'm hoping to join your community to get lots of tips on building RB motors. I'm not from Aus but I've found the best advice here, hope that's ok. I decided to start building an RB25DET as a hobby that I've always wanted to do. I picked up my motor from a scrap dealer as it was a damn sight cheaper than an RB26 or even a 1JZ motor but I'm super stoked to strip the motor down to the block and rebuild it to test my abilities. I've never built a motor before but have a background in Mining Engineering so not averse to getting into technical details. I wanna start off my first build with stock internals and see how things go from there 

 

Edited March 31, 2021 by RalfMurphy
Pics added

[Duncan]

sounds like a good project...do you have a future home for it?

It is worth getting the R32 GTR workshop manual, while the motor is not identical, the long block is very similar and it will have pretty much everything you need. There is also an R33 GTST workshop manual which is specific to that motor, but is in japanese

[GTSBoy]

Given that that's a Neo motor, there's also the R34 workshop manual out there to be downloaded. Filename R34 Workshop Manual English.pdf , size 12966KB (usually).

[RalfMurphy]

On 4/1/2021 at 10:59 PM, Duncan said:

sounds like a good project...do you have a future home for it?

It is worth getting the R32 GTR workshop manual, while the motor is not identical, the long block is very similar and it will have pretty much everything you need. There is also an R33 GTST workshop manual which is specific to that motor, but is in japanese

Thanks. I'm undecided between a 350Z or a BMW E36 or E46. I'm looking at an R33 GTS this week but it was imported and not legal as a road car (so would be strictly track or drift)

[RalfMurphy]

On 4/2/2021 at 1:28 AM, GTSBoy said:

Given that that's a Neo motor, there's also the R34 workshop manual out there to be downloaded. Filename R34 Workshop Manual English.pdf , size 12966KB (usually).

Thanks. I think I've found the right ones out there. Hopefully my copy has all the torque specs

[RalfMurphy]

UPDATE: I can finally post some progress pictures after a build that took far too long (the up's and down's of life). Certain things became apparent as the build progressed (like shipping times and duties, the price of any decent rolling and licensed chassis and how much little things like fittings and gaskets cost). Since anything besides GTR's aren't legal in my country, I'm hitting dead ends with viable and cheap chassis options. So I built the motor anyway and considering an S-chassis swap (S15 not legal either here so has to be 13/14's) or just to sell it off to someone in racing. 

I must thank all the users and admins on this forum as this was my greatest source of info and build tips. The project ended up being a 280-440fwkw build. I have no idea what power it will eventually make once in a chassis and tuned with whatever fuel gets used. But here's what I did to engineer out any issues (obviously all theory, I wont know until the motor is run):

All engineering and machining done by highly reputable engineering workshop:

Block chemical cleaned, deck skimmed to mirror finish, re-bored and honed to +0.5mm ● Crankshaft polished and internally rebalanced for rebuild components. Crank nose fitted with Nitto extended oil pump collar. Crankshaft oil gallery plugs drilled out and refurbished ● Pistons and rods statically balanced and matched ●  Cylinder head is chemical cleaned and rebuilt. Head is skimmed to mirror finish. Valve seats lapped and reseated. Head reassembled with new Nissan OEM valve stem seals fitted ● Rods crack tested and rebalanced. New ARP 2000 rod bolts fitted. Big ends resized for roundness at ARP torque spec ● Bearing clearances guaranteed at 0.05mm max for mains and rods

Long Block assembled by highly reputable drag builder:

All long block components buttoned and sealed ● Piston rings gapped to manufacturer spec (CP Carillo) ● Block fitted with 1.5mm and 1.3mm oil restrictors ● New seals fitted to the oil pump and main carrier ● New gaskets fitted throughout ● Water pump sealed with liquid gasket as per OEM spec ● Timing belt fitted with new tensioner and idler, tensioned and timed

RB Oiling problems addressed with N1 oil pump, oil restrictors in block, head rear drain, valve cover drains and oil pan return for catch can placement.

Max power of the build is limited by the rods and stock valve springs. I kept the head stock apart from the refresh.

List of components:

RB25DET NEO Block and Head
Stock crank repolished and rebalanced, fitted with Nitto extended oil pump collar. Even though this was a NEO, the crank still had the short oil pump drive. Must've been an early gen.
GTR rods (stock with the NEO) fitted with ARP 2000 rod bolts, big end resized 
ARP 2000 Head Studs. Stock Main studs
CP Carillo forged pistons, 86.5mm bore, 9.0:1 compression ratio (NEO), incl rings and wrist pins
Cylinder head refurbished with new valve stem seals. Stock cams with VCT
PRP 1.5mm and 1.3mm Oil restrictors in block
N1 Oil pump (stock with the NEO) fitted with new seal and gasket
Main carrier fitted with new seal
ACL Race Main bearings +0.025mm 
King XP Rod Bearings STD
Oil pan refurbished, repainted and fitted with -10AN oil return fitting  
Tomei 1.5mm MLS Head gasket. Cometic Exhaust gasket. New Nissan OEM Intake gasket.
Genuine Nissan OEM Gasket and Seal kit fitted throughout (except for head and exhaust gasket as above)
Original Splitfire Coilpacks (blue jacket) with new Nissan OEM Wiring short harness
Gates Timing belt
New OEM  idler and tensioner
New OEM dampened crank pulley
Stock water pump refurbished
Refurbished timing belt covers
Refurbished valve covers with heat resistant paint and -10AN oil drain fittings. New seals fitted
Rear Head drain from Hi Octane direct
New aftermarket Forward-facing Plenum with fuel rail and 90mm throttle body (water meth compatible). 
Aeromotive A1000 Fuel Pressure Regulator (flexfuel compatible)
New Bosch EV14 1000cc injectors xT compact type with extended nozzle (flexfuel compatible)
New Nissan OEM Thermostat 82.5° (wasn't sure whether to go with a colder setup since I don't know if the motor will run road or track)
New Nissan Fan belt
Stock Cam angle sensor
Stock VCT solenoid 
Stock alternator 
Stock turbo and manifold included but not fitted
Stock starter
Stock fan included but not fitted
Stock power steering and aircon pumps included but not fitted
Stock oil filter block and cooler. I'm contemplating a relocation kit with sandwich cooler.

Build still requires: 
Turbo and manifold to suit (I left this for now since it can be a personal preference of whoever buys this or whatever application it gets used in)
New spark plugs
New oil filter.
Flywheel and clutch
A decent ECU (Haltech, ECUMaster, Apexi, Motec etc) and sensors
All wiring and piping. Oh, and a freakin' chassis