GTRNUR

Im after a set of valve stem seals for an R34 GTR/Rb26 head. Seems Nissan Australia only have stock of a set of exhaust side seals... Will consider HKS or other brands too. Cheers, Ian

The VCT systems on the RB25 and NEO heads is sound in design, its the computer that lacks the capability to control it properly and in an advanced fashion. The early "clever" method used to be to control the VCT valve using the PWM boost control output of an aftermarket engine management system. Something that could vary pulse width based on RPM basicly. Any haltech, wolf ecu could do this. Once the frequency was worked out you can use that to control cam operation at any engine speed in a true variable fashion. If you want to get really sophisticated with cam control look at the Wolf V5 ECU and its multi-controller outputs. One 3D map with customisable axis's (eg MAP/Load vs RPM). You can then have override 2D maps based on inputs or any other signal, all output to a programable PWM output. Considering the effort he has put into in making the throttle bodies compatible with the neo head, its worth going the rest of the way and finishing it properly. Custom pistons can get a little pricey but there are other options too. Ive done a lot of research in this area recently with the engine project I am working on. Using off the shelf pistons from other cars allows you to get what you need a lot cheaper. Once you work out your head's combustion chamber volume in CC you can choose a piston to suit your requirements. Here are the options that I can see that you might want to look further into. These were all honda piston sets and all used a 22m gudgen which would mean machining or possibly special rods for the engine too. I know that some of the stroked versions of the EVO 4G63 engines run a 21mm gudgen and an 86.5-87mm bore along with good dish configurations that might possibly be a closer match for you. Wiseco Code Bore Comp height Dome/Dish Pin size K568M87 87mm 30mm -9cc 22mm K631M87 87mm 30mm -3.5cc 22mm K622M87 87mm 30mm -21cc 22mm K544M87 87mm 31mm -14cc 22mm

Talk to Steve at quantum racing ([email protected]) or +61 (7) 3290-5911. They are the australian distributor for CP pistons and yes they can provide you with any compression height, dish or dome configuration piston you like. You can just say you want a R34 RB25DET NEO configured piston with a 30mm compression height instead of the 31.5mm compression height and thats your problem solved right there. You can alter the dish/dome at the same time to get the CR you want too. Its always best to set the desired CR by optimizing piston design rather than running a thick head gasket. Aim to use a 1.2mm gasket and you'll be fine.

I used 3 channels from an MSD DIS4 to fire 3 twin output coils in a waste spark configuraiton on my first skyline. Apart from being a powerful ignition system that would throw sparks a good 3 inches plus it also had a few extra features that were handy. The main one was the 2 step rev limitor. I used that feature combined with an AUX on my ecu to trigger an ignition retard, base fuel map alteration and boost control. Instant programmable launch control. I could set any launch RPM in 250 RPM with any boost setting. If your building a drag car you want this. Combined with an auto with a trans brake I think it would be a great way to setup a car for straight line work.

Well you know about the VCT issue, so that means external oil line, and a welded or plugged VCT oil feed gallery in the head. Your next issue is compression ratio. The Neo head has a smaller combustion chamber than the RB26 (64cc ish). So the standard Rb26 pistons with their 15cc domes are going to mean you CR is going to be very high. Rb25 pistons have a 11cc dome but also have a 31.5mm compression height so they would be sticking out the top of the block. You cant use RB30 flat tops straight out of the box, as they are a 32mm compressio height, and the compression would still be high. The solution that is worth investigating is trying out some modified RB30ET pistons. First off they are dished so that will help with the compression ratio. Second, they are a 32mm compression height, but you could have them machined back to 30mm (and that will remove some of the dish), and that will achieve the 0 deck height. The next option would be to machine the same RB30ET pistons for a positive deck height, so they protrude out the top of the block by 0.5-0.8mm. Then run a 2mm head gasket to achieve a safe piston/head clearance. This way the top of the crown is more intact (only cutting 1.2mm off it), and it will all fit inside the block and under the head still. On the bright side, the RB30ET pistons are way cheaper than the RB26 stuff, and some 2nd hand pistons to do a trial fit-up with can be found very easily. Cheap as chips or free even. As for the water gallery and oil return lineups, you will need to ask the guys that have done a NEO head on the RB30 block before to ask what pitfalls they encountered. I believe Spool Imports have done one for starters... Cheers, Ian

Sounds like un-charted territory to me. It would be a lot easier to run the RB26 internals in the RB25 block instead to get the same displacement and not have any assembly issues. Unless your after a means of retaining an AWD block that is.

Its still in a sold pending payment holding pattern. The guy that wants the bar and lip is owed money from other people and until they pay up in parts/money the bar is with me. Im not in any hurry to move it and for the moment I have plenty of storage space I havent taken a deposit yet though, so if your willing to come up with some coin first then by all means its yours.

HA HA Hardly recognise your old engine block hey! Yeah 500awhp would be plenty. The driveline is stock in the R34, and I dont want to turn the car into a bitch to drive by filling it with neoprene bushes etc. Ive gone with a coppermix nismo twin plate too, and to make that last 500hp is a nice safe limit. Realisticly I'd be more than happy with 400hp, but the fattest and widest torque band ever. I like motorkarna and sprints. Not into drag racing so much.

Well problem solved, I dont need to worry about R32/R33 heads now. I'll be able to confirm the CAS drive diferences for sure in a week or so. Just sourced a low K R34 head from a vspec 2. Cheers, Ian

Small for response. Being a big motor it doesnt need to rev, though it will do 8k max. A pair of HKS2530's most likely to maintain a stock appearance. GTRS's at most. I'd prever something some middle ground between these two turbo's, might require some more investigation. Thats a long way off though.

The prototype is going to be 87x87 (3104cc). The crank is a modified RB30 crank, long rods, custom pistons and custom order dartron sleeves. I made my own spacer plate based on looking at a lot of pictures I obtained of other open deck engines. The engine will be 20mm taller than stock. Its going to be a couple more months to finish but i'll post up the build of it when its all finally going together.

Well it looks like i'll be using porsche 928 head studs in this first build. They are certainly up to the task. Also, for those that were interested I have attached a few pics of the machined engine block. The sleeves still need to be bored out to match the pistons that should be arriving in 3-4 weeks, which isnt a bad thing.. because Ive decided to change the bottom end of the engine a little. Im changing the crank modifications a little and getting a set of pauter x beam rods for it. Considering this prototype is going in the R34 I want it strong as hell. The x beams should make the bottom end capable of supporting 700hp easy. Im not running an ARP main stud kit in this engine, which is really the only limitation as to why it wouldnt reliably handle more power. Power isnt what this is about anyway, its about response, mid range torque and reliablity.

Hi guys, Im trying to source a cylinder head for the new engine I am building for my R34 GTR. I want to kee my current engine intact as a spare and build an entirely new engine and just do a swap when its ready. So, apart from some porting, what exactly is the diferences between an R34 and R33/R32 RB26 head? I believe the R34 exhaust camshaft is slightly diferent so it can drive the R34 CAS sensor. I want to keep all R34 sensor compatability so I can run an FC on the new engine, so to do this can I buy an R32/R33 head and then just put a set of R34 cams in it? Cheers, Ian

You have a PM.

Im interested in the ACL main bearings if they are standard/standard size.

Here is the service manual data for the O2 sensor. Also, get some CO Contact cleaner and hose out your MAF sensors. O2.pdf

Ah... sorry i misunderstood. No they are both supposed to change. You definatly have a dead 2nd o2 sensor. Some widebands setups output a simulated narrowband output too. You might be able to wire that to the ecu instead of replacing your dead sensor.

It was the one with the -6 outlet/return and twin -6 inputs. On the v8 we had a return from each rail to each side of the pump. The supply line from the pumps was T'd at the engine bay to supply each rail. I just noticed HP in abox do one with a -10 fuel return too. Might be more suitable for you.... http://www.horsepowerinabox.com/HPIAB2/category10_3.htm Electronics are my background, though not the industry im working in at the moment. We live in a disposable world these days and nobody fixes anything electronic anymore. Replacing the reg is going to be the easiest and simplest option. The electronics approach might work but adds complexity and a point of failure. Simple is usally best.

One other thing... I ran twin 044's in parallel using an SX regulator and had raised the base fuel pressure to 65PSI on a turbocharged 1uzfe v8 I was messing around with 2+ years ago. It worked fine and had no surging issues. Max on boost pressure in the rail would have been 80psi. All fuel lines were 3/8th ID. It ran a T from the two pumps in the boot to a single 3/8 supply, and single 3/8th return. This was the "cheap ass" approach to not buying a set of larger injectors that the car really needed.

The standard FPCM uses two inputs to switch from slow (0v, 0v), to medium speed (0v, 5v), to high speed (5v, 5v). I am pretty sure that the outputs from the FC actually pull the output signal low or high. They dont tri-state (float) the output. I have no idea what the current driving capabilities of the outputs are. Considering they are driving a solid state relay, and the length of the wire from the back of the car to the ecu at the front I would say its got to be pretty low. So to use the outputs you would be best to source a solid state a simple solid state relay to replace the FCPM. This might sound a little complicated but here goes... You can make a very simple solid state relay using a a few cheap components from dick smith. Get a single BUK456-60 mosfet and a 1n4001 diode, and tear out the page from the dick smith catalogue . It shows the Gate, source and drain pin outputs for that mosfet. The Gate connection goes to the Power FC output to trigger switching on at 5v. The source goes to your fuel pump's -ve connection and the drain goes to Ground. The diode goes from the source to ground (accross the mosfet) to protect it, white band end toward the source. Put a 15A fuse betwen the pump and the mosfet too. This circuit will switch 60 AMPS from a very low current 5 volt input.

With closed loop off the idle afr regardless of what it is should be stable. Lets assume you have a 14.7:1 afr at idle, that should be 0.5v on the narrow band. The factory sensors have a very narrow operating band where 0.45-0.65 is the only usable voltage range where the afr can be read accurately. The limits of the sensors range is 0v = lean and 1v = rich. Yesterday when you saw it cycling it was the computer operating in closed loop mode trying to hunt around the 14.7:1 afr of 0.5v. It will stay on the rich side of things with the o2 feedback turned off.

I kept that really simple. A standard RB26 or RB30E head gasket with the center cut out of it to clear the sleeves will do the job, sprayed with some hylomar. I considered making up a copper gasket cut but frakly the price of copper is crazy and using a propper gasket is a cheaper and probably a better option. The spacer plate can be bolted to the block with a set of 50mm allen head bolts and torqued to spec with a gasket installed when the block is decked. The other option was to mathmatically work it out and set the sleeve height to be about 3 thou higher than the spacer plate and spacer plate gasket to get a better cylinder-head seal. This is one of dartron's tricks with how they recommend setting up sleeved block top ends. Im keen to see how long the TB45/48 bolts are. Shame there arent many of those engine around dead to pull apart and check out. I figured they'd be built like a diesal though being that the blocks are milspec rated.

Yeah but its a fine line to cross asking these guys to share the knowledge freely that they use to build their top level engines... If they were willing to volunteer the informaiton freely I'd really appreciate it, but I understand completely why they'd hold most of their cards for an open deck engine close to their chests. After all its their livelyhood. Also i'd wager they are just using ARP anyway. I was hoping for an alternative and dont need the strength nor the expensive of ARP. Im not building some 700+hp monster. The engine will probably end up with a pair of GTRS's on it and not reving past 7500. 500awhp would be plenty. Its built for torque and low to mid range response.

Your using an R33 GTR PFC right? The output signals from that ecu should still be able to be used to control a second pump. Sure you wont have the FPCM, but you wont be needing one anyway. Basicly they are a solid state (transisitor/mosfet) relay anyway... If you have an R33 GTR circuit diagram its pretty easy to trace the wiring back to what pin on the ecu you need to steal a signal from.

Thanks for the pics of the bolts too Shane. Interesting the little ridge at the edge of the 12x1.5 thread on the block end of the stud, and looks like 12x1.25 at the other end right?