GTRNUR

Don't do it Pete. After my 4th or 5th variation to my fuel system I've finally come full circle back to twin in tank 044's. Its a mission to get them in there, but worth the effort. Concealed, no mess, no fuss. No in car fuel smell. The only other practical option is to go with a custom under spare wheel setup with external pumps, and the standard pump as the lift/filler pump. In boot surge tanks take up space, leak vapour, and just get in the way. Technically not legal either, as the firewall is not 100% sealed between the driver compartment and the boot like it is with the engine compartment.

I like the look of that graph. It basically proves my goal of 24lb +E85 will produce 550kw on a soft tune with my 6466. On the stroker/rev topic. The full counterweight 90mm crank engine I have now feels way smoother than the modified 87mm stroke RB30 crank I ran in the previous engine. The limit for most motors these days is what rod bolts are used. Piston metallurgy/forging and designs are being proven to 11,000 rpm on short stroke engine, however you need to look at the piston acceleration rates from TDC of an RB26 vs RB3X engines to see the difference on engine stresses. From memory, 8000 in my motor is close to 10000 in a 2.6. Longer rod engines have more mass swinging around too, which puts more loads on the rod bearing and bolts at higher RPM. (Correction) Less of a factor for the 2.9lt and less crowd though. Beyond revs though is when your cylinder pressures start causing issues like lifting the head (stretching head studs), grinding rod bearing/journal contact due to compression of the lubricating oil film, and pushing the journals out of round for the really insane power levels. When you think about it, it is these last few things that make the 2J the stronger performer as the big power engine typically run 1/2" 625 head studs and the bottom ends are like a diesel engine.

I actually tried a walbro 460 as a lift pump at one stage, and discovered they need to have the base of the pump wet in order to prime. The mount for the fuel pump in the R34 is half way up the height of the tank, with a long pickup hose that goes down into the sump of the tank. I believe I needed around 500-550lt/hr at 75psi to meet my power goal. There is two types of wire on the PHR fuel tank hat. Two small grade wires for connecting to the gauge sender circuit, and the other wires are much larger. Its milspec wiring with thin insulation and silver plated conductors. It will easily handle 20A.

The R35 brake setup that I've gone with isn't exactly a typical setup. It took a bit of work to get it in there but the results are very impressive. The front rotors are 390mm Alcons with factory R35 callipers and endless calliper adapters. The pads are PMU carbon. The bite is good cold, but when hot they are mind bogglingly good. I have to do a 100-0 brake test at some stage. Rear rotors are DBA 380mm T3. The factory handbrake is used. No issues with the master cylinder size. From what Ive read on the UK forums, the R34's MC is bigger than the 32/33's and is considered acceptable to use with the R35 callipers.

I am told that everything to change the clutch has arrived, so all going well I will be able to get it booked in for the clutch swap next week. In the meantime I have been working on the fuel system again. My powerhouse fuel hat melted another electrical bulkhead seal, so instead I've re-fitted it with an o-ring seal this time. WIth any luck this will solve the fuel smell in the car issue. I've also decided to do away with the external surge tank, and spent the afternoon in the boot of the car trying to shoehorn a pair of 044's in there. After about 3 hours I finally got them in there and mounted. What a mission. I think that triple walbro's would have been a lot easier. Here 's a few pics of the PHR fuel hat for those that haven't seen them.

The new NPC clutch is here but the push to pull converter must have fallen off the boat on the way from Japan, MIA. I did put an R35 brake setup on the car though, which makes stopping as much fun as accelerating!

I'd rather not go putting any kit style guestimate pricing out there just yet. I am planning on doing 2 more prototypes. Once they deliver some fruit, I will be asking for a production run of crankshafts and the necessary components as a bulk order. This will significantly reduce the costs as well as raise the bar on the quality of the product at the same time.

I was lucky with this Nitto crank as it was a one-of that they had on the shelf, so I got a good deal.. Not sure why they made it either. Possibly just because... I've just made a new crank for one of the next two engines which is 87.8mm. All up cost for that came to about $5700 I think, as it is essentially a customised Nitto Rb31 crankshaft, however using GTiR rod journals and it retains the oil squirters in the RB26 block. Prototypes aren't cheap.

The slippery clutch is still in the car. Not sure how shagged it is yet. Yes when the new clutch arrives the wick is being turned up. My goal is still to make 500kw atw on a soft E85 tune, which it should do with ease. 450kw looks to be easily achievable on a low boost 98 tune. Trent wants to turn up the boost to 30 and see how it goes in top end. We'll see, I might have to go for some drinks if that happens and just leave him to it.

Based on recommendations from Trent @ Mercury and Dan (owner of LK Motors who's dyno we used), they actually agreed on the same type of clutch and I am fairly certain it is a custom setup. There is a pull to push converter required, and I believe it uses 1 x carbon and 1 x copper organic disc although don't quote me on that. I believe it is identical to the setup in Mercury's Nitto. To be honest I left it in their hands to sort out and just paid the bill. I've been too busy with other work this past 3 weeks, which is good considering what will end up being a 4000-4500 change over cost. Not to mention the brand new exedy carbon twin plate that is in the car is probably a paper weight now. It would be interesting to know if it is salvageable, or if its now looking completely shagged.

I don't believe square, under or over really makes any difference to be honest. It is just one of those facts that IS about engines. A lot of people have a differing opinions about what works and what doesn't. What it comes down to is more displacement is better if you are after more torque and power, and less lag. Simply because your moving more air. This is an 89mm bore and 90mm stroke too. Although the sleeve design will support a 90mm bore still, while retaining more cylinder thickness than a 24U block would have with an 87.5mm bore.

Still waiting on the clutch. I've got to chase that up today as its been a couple of weeks. It is a custom made NPC unit though and I have no idea what their turn around time is.

If its a standard head gasket you may have already damaged the fire ring beyond where it will seal again. A burnt fire ring and carbon deposited on the seal surface will be the end of a good seal fore sure, regardless of clamping pressure achieved with ARP2000 head studs. If the head has been off before and its now running a metal shim gasket, then thats a whole other can of worms which has thouraghly been discussed here already. Yes you can access head bolts without pulling the cams out. I recommend getting a telescopic magnet to allow you to retrieve the bolts easier.

For a cylinder head, yes I'd agree. But what I have in mind is more like you'd see on a connecting rod, with a dowel that is hollow, tapered and is an interference fit into the block and girdle cap.

Has anyone ever tried doweling the main stud girdle to the block to eliminate girdle walk, while not also having to deal with added below the block height that girdle plate/adapter plates make? I figure it could be done with a bunch of 8mm tool steel dowels next to the main bolts, or alternatively with hollow chromoly dowels that would slip over the main studs and be recessed into the block and girdle. Doing this as opposed to heading down the billet main cap/girdle plate path would mean no align bore needed, so typical wet sump pumps are still able to be used. I would argue that it would be just as strong from a main-cap perspective too, as eliminating girdle walk ties the girdle and the block together more firmly. Where as an alloy billet main cap can still walk on the block, and is relying entirely on the rigid strength of the plate to reduce block flex to reduce main cap walk. Any thoughts?

I was seeing about 5lb at 2000 rpm and 18lb aroudn 3400 before it was tuned properly, so it it would probaby be even better than that now. Although now with the 10lb gate springs springs the gates bleed little until max boost is reached so it will be a little more laggy. Something I hope to have remedied soon.

I used a Gorilla supplied PHR bulkhead with twin 255 walbros as lifts, and a Holley 1800 pressure pump. The 255's flow 300lt/hr with no head pressure, which can keep up with the 1800. I have paired one lift with each side of the pressure pump, and use speed control and pump staging. As Darren suggested though, the 5LT AI tank with 1-5 pumps makes good sense. Use the stock or a 460 as a lift pump (R32's only), and use the large surge tank as a main supply source. This makes the most sense or R33/R34's too, as there will be no issues with the size of the return pressurising the surge tank, yet the syphon venturi will still work.

Stick your finger down the front/left oil return on the block above the thermostat, and you will see the depth that the stud support goes to in the block. This is the reason a cnc machined in closed deck support plate will not work on an RB block. The outer edges of the block and stud holes are supported by the deck of the block, which in turn is supported by the cylinders, attaching it to the material around the crank. If you machine out the entire deck of the block, the supporting material isn't there anymore. The EJ257 block head studs go all the way down to the main stud material, so open deck blocks can be converted to closed deck with no problems at all. I've had some thoughts about a Siamese cylinder option too. After thinking it through though its harder than what I have already done.

All good Mike, if you ask a question I don't want to answer, I just wont answer it! To be honest the risk in my design isn't the cylinder thickness. My main concern was if I had got the compression calculations correct for the gaskets either side of the spacer plate. Getting those wrong could have meant I'd pull the material that supports the studs right out of the block. I don't think my sleeve design can be applied to a closed deck block to allow a bigger bore, as your risk then really does become the thinner bore thickness. Considering your into coolant past 92mm when sleeving, to keep your bore thickness up you could only go to 95mm, but that is the maximum you can go to. As you would need at least 0.5mm of flange on the top to stop the sleeve slipping into the block. Resulting in 2.5mm of cylinder thickness with the 90mm bore, partially exposed to coolant once the piston passes below the deck. That is thinner than any un-supported cylinder in any engine I have researched. You would have a thin wall, as well as a thermal expansion induced stress concentration issue.

Hi Mike, I've had 3d modelling and FEA done on the sleeve design to indentify all weak points. I use different interference fits on the stepped sleeves at different heights in the block to eliminate weak area's, which results in those weak points being stronger than other areas that are thicker material. The spacer fitment and o-ring keying to the head help too. Also consider that highest combustion cylinder pressures will occur within the top 30mm or so of the cylinder bore. This is in the thickest area of the exposed sleeved cylinder group, which becomes effectively solid where the sleeve passes through the deck of the block. As everything is interference fitted, there is no room for pressure induced expansion to distort a cylinder or induce a failure. The weakest area of the sleeve is where its thinnest, at the bottom of the block. This area is also the most stable area of the factory block though due to being solid around the main bearing saddles, etc plus aided by partial block filling. And yes, there is considerable porosity in blocks. There is a reason they say to not bore past 88mm, as the porosity and poorly cast metal in a factory N1 block begins to get sketchy at about 91mm, and at 92mm you are already breaking into water area's between cylinders and also low in the block around welsh plug height.

Update Time! Its been a long road to get here, but I finally have some test results for the engine. Last weekend Trent Whyte and Gordon Leonard from Mercury Motorsports jumped on a flight to tune my car and a few others at a workshop in Cairns. It was a big weekend and nearly all the cars had problems that required some serious work to sort out. My car wasn't immune to this either. Once a fuel system issue was sorted out the tuning began. Almost immediatly we encountered the next issue, which was that at the lowest boost level the engine was already exceeding the maximum torque for the clutch. Trent tried making the tune as soft as was possible, but it still refused to hold. In the end I had no option but to switch out the 18lb wastegate springs for a pair of 10lb springs. The following day the car went back on the dyno. The clutch slipped initially but held once it was up to temp. Trent was able to finalise the tune and complete a 12lb wastegate tune on the car. While not the huge success I was hoping for, we did see a glimpse of what the engine is capable of. Here is the video : Turn up your speakers - or if you prefer to think that stroker motors can't rev, then turn them off. In the coming weeks I will be sourcing an NPC 1000hp twin plate carbon clutch, to replace the exeedy twin plate. Once done, Trent will be back to Cairns to complete the 18lb tune, and then crank up the boost with E85 race fuel. That is all for now.

The last stock R34 pump I saw had 8 blades and no plate. The N1 was 6 blades with a plate. Can't remember the last RB30 I looked at before it went in the bin.

The ATI 1000hp balancer kit that I have came with an oversized (under drive) pulley for the water pump, which when used with an N1 pump is borderline for street use. I believe ATI's gearing ratios are meant for a stock pump. And the N1 pump would be a good match for stock balancer and pulley sizes.

What ECU are you using?

Is your crank grub screwed, or does it have the factory plugs? What about the block? Did you drill and grub screw the main oil gallery at both ends, so you can push a cleaning plunger through from the main oil bearing oil feed groove to the main gallery? I've heard of the incorrect thermostat hook-up killing engines before too...Multiple times too sadly...