HarrisRacing

This pretty much has me convinced of the 6262. Are you on a stock stroke and/or displacement? I have a BC stroker motor on new N1 block (std bores), ported head, SS valves, Tomei Poncams A, etc. I'm going for a nice response build. Another shop is trying to get me to run their billet (not precision) version of the 6262 and I may take them up on it since he's offering a great price and warranty. He just wants to see what it will make on a good RB26 setup. They have made 640 whp on a stock 2JZ with their 6262 and wanted to see what it would do on a built 2.75L RB26. What manifold is everyone running?? I don't want to have to change my R32 PS or A/C out to later.

Interested in seeing 5862 as well. I have a 2.75L BC stroker build on stock bores (N1 block) and I want something super responsive for pumpgas on the street. I'm not one for E85 or racegas because they aren't really available in the area. I'm betting my stroker, with Poncams A, ported head, +0.5mm SS valves, etc will run pretty dang good with the 58mm turbo.

Oh and they are cut at an angle about 20 deg from horizontal plunging in from the outside to the inside. This is why they look shallow. They follow the angle of the squirters.

modeling clay showed me where to cut. Then I made several cuts on the first one and kept checking. Once I got that one done, I measured from top of piston with calipers and cut the rest. It was directly inline with one of the oiling holes for the rings, so alignment was easy. I still think I barely missed the angle, but they all have adequate clearance. Plus the rods grow when they get hot, and yes the piston grows down on the skirt, but only from the wrist-pin down. I can run calcs, but I'm betting nothing will touch. Patrick.

I used a bit of modeling clay on the skirt of the piston and ran them down. Yes I have about 1mm clearance. I wanted to be able to lose a rod bearing and not break a squirter off. Thanks for the replies. I was worried that I was the only one and maybe they sent the wrong pistons. Patrick

Well I decided to relieve the pistons. I can't wait another 2 months on this project. Took some measurements and cut the Pistons. I got my scale out and sanded them until they all weighed the same too. Very very little change to overall weight and I would say it's negligible. bottom end is together.

I am putting my engine together this weekend and just discovered a clearance issue with the oil squirters and the bottom of the pistons. The crank is BC 79mm stroker (2.75L on std bores) and I have a brand new N1 block. The pistons are CP that came with the stroker kit and as you can see from pictures the bottoms of the pistons do not look relieved in the correct location nor are they deep enough for the stroke of the crank. The piston hangs up with approx 15 deg of rotation until BDC each way. Deck extension at TDC look like they are def stroker pistons so the wrist pin location is correct, just not relieved on the bottom. Has anyone seen this with this setup? Perhaps they just cut the bottom for the wrong stroke? They also look like they mossed the location relative to the piston by about 10-20 deg. I have a call in to CP Carillo but I was curious if any builders have seen this?

Thanks for the advice on the oil control thread. Started making a lot of sense to me about vapor flows and separation. I'm going to add some ports to the oil pan and engineer a catch can setup and drain system as well. I forgot to add I have the tomei oil restrictor as well. E85 is available about an hour away from me, but I'm not planning on relying on it. Pistons are done so 8.5:1 is going to stick. We'll see what boost she'll take on that.

Thanks for the advice on the oil control thread. Started making a lot of sense to me about vapor flows and separation. I'm going to add some ports to the oil pan and engineer a catch can setup and drain system as well. I forgot to add I have the tomei oil restrictor as well. E85 is available about an hour away from me, but I'm not planning on relying on it. Pistons are done so 8.5:1 is going to stick. We'll see what boost she'll take on that.

My apologies...8.5:1

Forgot to add Full BC gasket sets ARP head studs, main studs, FW bolts I'm sure I'll remember more when I get back to the shop and look at the obligatory fast-n-furious spread of parts.

Greetings, I'm nearing the final commencement of my engine / R32 GT-R build here in the states and wanted to start a general "help me avoid trouble" prior to putting this thing together. I bought the car with a rod knock, when ended up being a bad crank, which turned into finding the small water-jacket-to-head-stud-hole cracks on the exhaust side (5 of them!), so here's where I am at today. Bottom end: New N1 block (standard bores) Brian Crower 79mm rotating assembly CP 8:1 86.00mm stroker pistons (came with stroker kit) Fluidampr harmonic balancer Tomei Oil pump HKS timing belt All new tensioners and pulleys Greddy TRUST oil sump extension Exedy hyper Single VF clutch and flywheel kit (OK this was one of my first purchases, when I was just going relatively mild rebuild!). WHAT CAN THIS HANDLE? looks like only 500nm to me! http://www.exedy-racing.com/racing/en/pro/hy_single_vf.html http://www.exedy-racing.com/racing/en/pro/selectionguide.html Cylinder head: Ported stage 2 cylinder head by RAWBrokerage (still waiting on this, shoudln't be much longer). BC phosphor-bronze valve guides (all) BC +0.5mm SS valves (do not need to work seats for these like you do the +1mm) BC locks BC Ti retainers and single spring kit Tomei Poncams A (again ordered when things were going to be more stock-rebuild) Rear head drain fitting Mine's triple baffle cam covers Turbo / Other: GT2860 -5's Ported dumps, matched and mildly ported manifolds. Will build custom intakes to remove AFM's 850cc injectors 300 lph pump Haltech Platinum New Koyo Radiator Braided oil feed and drain lines for turbos New CV boots (all) Whiteline HICAS elimiators New steering / balljoints (all) Remaining TO DO and misc. Questions: Oil cooling (HAVE NOT PRUCHASED YET - affordable recommendations or U-build-it kits?) Transmission? What breaks and when!? Should I just plan on changing clutch and purchasing R34 6speed conversion now? Is it even worth installing the clutch I have?) Block Grouting? I assume this is only for SERIOUS builds, but does it help with cooling on road course? I don't see this car going more than 700 BHP ever, more of a response / track day car (on occasion). Intake manifold? Suggestions / Requirements? I may put a mid-sized single on later, but if this setup will give me 500 whp on pumpgas I'm probably not going to bother with any more HP. I do not plan to drag race the car, but It will see some trackdays. Any and all advice is much appreciated. I honestly would rather someone jump in now with "Don't do xxxx!" than have to re-do or re-install anything later. Patrick (in USA!).

Update: Well we found the tell-tale cracks from the coolant jacket to the head stud holes and I decided to not use the existing block. I have an N1 block at the machine shop now and I had to get new pistons for the BC stroker kit. I also found a chipped valve guide! yep a small part was missing and no doubt made it through the engine at some time so I went with BC bronze guides and while I was at it went with new +.5mm Stainless Steel valves. I also took the time to mildly port and polish the head as well. It came out great! It sure has racked up the money on this build from where I wanted to be so I'll be selling the -7 turbos shortly to go bigger (for sure). I'll keep you guys updated, but work has been insane this year. Thanks!

Sweet! thanks for that!

I'm going to try the drop in poncams type A. Probably too small for my engine but I compared them to supra 2JZ factory cams which is a little closer to what a stroker is and I'm going to see what they do. I also got cam gears in case. If I decide these are too small I will spend much much more and go with real cams later. Does anyone know how much I need to relieve the head for the cams while I'm porting it for the larger cams later down the road? Lifters, springs, retainers and "Pro" cams came out to somewhere around $1500 US. This is before nailing down shim height and ordering correct shims.

I can assume based on your signature that this is with stock turbos and stock displacement? Also assuming stock springs?

Sorry if it sounded like that...just trying to add more data to the pool so I can make a more educated decision. Your input is appreciated greatly. What I was noticing were things like someone taking a stock or aftermarket camshaft and dialing them in using adjustable cam gears and still making great power increase with NO changes to cam duration or lift whatsoever, but simply changing overlap timing by changing cam timing. One example is on post #19 of this thread: http://www.sau.com.au/forums/topic/93880-rb26-turbo-upgrade-all-dyno-results/ He makes 17 more KW and greater power everywhere in the curve from just changing cam timing...seems like a lot of power increase from rotating cams and from what I read most people don't move them more than a few degrees apart. In the list of durations of "bolt in" cams there is clearly more than just 4 degrees of cam timing changes going on and it's leading me to believe that there should be more room in there even on the smaller turbos that I will be running to gain some response from changing out the factory cams and likely even more response when I get them timed right on the dyno.

Doing a bit of research online shows the following: Description, Advertised Duration (IN/EX), duration at .050" (IN/EX), max lift (mm) (IN/EX) Stock, 256/256, 209/206, 8.51/8.18 Poncam R, 250/250, 216/218, 9.15/9.15 Poncam A, 260/252, 222/214, 9.15/9.15 Poncam B, 260/260, 222/224, 9.15/9.15 (uses exact same intake cam as Poncam A but longer duration exhaust cam). BC Stage2, 264/264, 222/224, 9.14/9.19 Honestly I have a hard time believing that there would be little difference in powerband between these cams and stock cams. All gain 0.64mm of intake lift and ~1mm of exhaust lift, all gain at least 7 deg on intake and exhaust at .050". It also shows that the ramp rates of these are all substantially quicker than stock as the "advertised duration" and "duration at .050" are spread far apart on the stock cam vs. the others on the list. It also tells me that the BC stage2 (only ones I see that they sell for the RB26) are very similar to Poncam B. Note, we didn't get to the "pro" larger lift/duration cams (requiring use of larger springs, etc) yet. I like how the mine's cams have larger lift and mild duration. Big duration to me often lets boost blow out the cylinders, but the lift helps all around if you get the ramp rates correct. FYI I will already have stiffer springs in the engine...not sure about titanium retainers yet or not, but at the minimum manley replacement valve springs which have a nice increase over stock seat and @lift spring pressures. And I think the reason cams get a bad rap is that they are expensive and a lot of work for the HP gains...$2000 in turbos can make FAR more HP than $1000 in cams and springs.

I am building my R32 (build thread on this website under that section), and have ordered the Brian Crower 2.9L stroker setup for it. So far I have all of the oiling mods (including Tomei oil pump), and am gonig with 86.5mm bores with CP 8.5:1 pistons. I also jumped the gun and ordered some GT2860-7 turbos since they were on sale when I was initially ordering things for my car before I knew the stock 2.6L crank was bad. I will likely run these turbos for a year or so and then go straight to a single turbo setup BW EFR 7670 or BW EFR 8374. I am wondering which cams I should go with that may possibly cover both setups or if I should just go stock now and a larger set later. What do you guys think about Tomei Type A poncams? type B? BC offerings? Those with actual 2.8 or 2.9l stroker builds please chime in. I have searched through the dyno databases and haven't found a solid comparable setup yet. Thank You Patrick

Well we are taking a step back now... Good thing I didn't order the pistons and rods that I was literally about to click BUY NOW on. The Nissan crankshafts are apparently on some intergalactic backorder and lots of people have been waiting on them for quite some time. I was notified that my order was backordered so I'm going back to the idea of going stroker and have decided on the BC 2.9L kit with the 79mm stroke. I am decided on the "sportsman" rods in this package as the only difference between them and the +625 rods are the fasteners (I talked to the BC tech about it). He said the sportsman rods would be very good likely up to 900-1000 HP depending on revs and that the 625 rods should be used after that. I'm wondering which pistons (CP or JE) and CR to get as there are many options offered for both. I like to err on the side of more compression (9.0:1 max) as it makes for a more fun streetcar, but this one is already going to be stroked so maybe this won't be required...Maybe I'll just spec the stock 8.5:1 Despite the oiling and seriously strong rotating assembly I think I'd still like to set target revs around stock (7,800?) for insurance purposes. Looks like the build is going to be a bit more power anyway now so those -7 turbos might not be on there very long Patrick

Still going strong! Did the busy work today. CLEANING and CLEANING oh and CLEANING. Then got the bug to do something fun so I ported the manifolds at the turbo inlets. I also fix and retapped some broken bolts and then stoned the faces so I'll have a better sealing surface when it's time to go back together. Had more time so I took a better look at the turbo outlet pipes (O2 senser housings) since I am still decided between the tomei set or not (WOW they are expensive!). I came to the conclusion that for -7 turbos that I have on the way that they are fine after a bit of porting. Actually the shape of them isn't bad at all, but the CASTING from the bottom to about halfway up is terribly jagged. There is also a step in the outlet so I basically smoothed that and then ran my grinder as deep as I could up inside the housings to knock off the casting roughness and then ran the sandpaper flap wheel to smooth it out more. I think for the small amount of time spent on these few things I will see big changes on the spoolup and power. I also cut the TWIN TURBO pipe for the slip-in divider. I need to hit the hardware store tomorrow to get some aluminum, but I'll bring this and the oil pan (Greddy sump on the way) to get welded up soon enough. Next will be porting the heads (mild cleanup only), and lapping valves...I will check the valve guides while I'm at it. Also tomorrow sometime I'll make a detailed list of what parts I plan to put on the car. Patrick

Found a new OEM crankshaft for $1200...LOT of money for any stock crankshaft IMO, but it's brand new and with new forged rods and pistons it should hold up well. There were some scratches in the bore of #5 and 6 that I could hang my fingernail on so I'm going to order 87mm pistons for it. I put the extra "stroker money" towards a Tomei oil pump and a new clutch (Exedy hyper single VF). To answer your question this car will likely be able to push 400HP to the wheels pretty solid I would guess. If I'm not happy with that, the twin GT2860-7's will be coming off and a single will go on. Still debating which ECU to order. Also debating valve springs...are they needed for Tomei Poncams B?

This is solved. I found a decent price on a brand new OEM crankshaft...saved about $2k. Spent that money on Tomei oil pump and new clutch. Thanks!

No...that's why that option is pretty much out. I'm sure freight would kill me. I can get the BC 2.9L stroker kit for $4800 or so US. I was already budgeting $1400 for rods and pistons, so this is like a $3400 crankshaft adder. In all honesty I would be looking at a NEW RB26dett crank either way because I don't want to mess with regrind etc after I have seen what happens inside these engines first hand, plus the fact that there aren't piles of them in the junkyards. Of course the stroker comes with a better powerband. I can get Tomei for around $5000 US. From what I understand the Tomei is lighter and is shorter stroke...so slightly less displacement, but I'm sure it's still quite responsive. They offer two different pistons as well...valve relieved or not. Anyone know if there's a power/response difference?

I know it's been asked and I'm looking, but the search returns quite a pissing match. I just ran into a serious issue with the bottom end. Crank is trashed. Bent .014" out at the center journal and goes down from there right where I marked the crank. All the mains were trashed and it spun rod bearings 5 and 6. More information on my build here: http://www.sau.com.au/forums/topic/447384-r32-gtr-build-in-usa/ I am moving QUICKLY on my build and I don't want to wait to order such a long lead item like a stroker kit but if I'm paying for a crankshaft I might as well get a good one! Anyway, can anyone tell me any +/- on the Tomei and the Brian Crower stroker kits? My build will have brand new GT2860 -7 turbos (I know stroker on this?!), but yes I ordered them already. likely 600 or so cc injectors, fuel pump, either Haltech Platinum or Adaptronic, Tomei type B cams, oil baffle, oil restrictors, rear of head oil drain, ported factory manifolds, and likely run stock turbo dumps but full exhaust otherwise. Basically I'm looking for a FUN street car that can keep up with some of the newer cars without being a racecar. If I go to bigger turbos later it will be a single in the GT35R size range (500 rwhp on pump?). Any and all REAL applicable advice would be appreciated. Tomei kit doesn't stroke as much as the Brian Crower, but it's lighter. I'm sure both will greatly help response. I'm likley going to keep the revs under 7800.