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Hi all, I've finally decided to crawl out of my cave and surface my build here. I felt like I was taking more from this forum than I was giving. My build used a TON of info that I was able to unearth via this site. My hope is that my build adds to the plethora of information on here and helps others as much as it has helped me. Anyhow, I've been trying my best with the limited network/connections I have to get suggestions on where I should start with jetting for my turbo surge tank set up. I feel like I hit a dead end. I know that I have to fine tune the jetting for MY set up...so I'm currently in the process of installing a wide band O2 sensor and a boost gauge. However, does anyone here with experience have a ballpark estimate on jet sizes in an application like this? I don't want to start tuning my engine and have it catastrophically fail or damage my newly rebuilt motor because my jets are way out of line. Here is my set up: Engine: L28 N42 Block E88 Head (Debating on whether or not to install my spare P79 head in) 280zx Turbo dished pistons .020" oversize 1mm headgasket Stock L28 rods 280zxt stock exhaust manifold Custom 2.5" to 3" turbo back exhaust T3 Turbo w/internal wastegate: Compressor: Trim:55 Inducer Diameter:50.5 mm Exducer Diameter:76 mm A/R:0.5 Turbine Trim:73 Inducer Diameter:65.5 mm Exducer Diameter:55.9 mm A/R:0.63 Triple Mikuni 40PHH Carbs Main Jet: 145 Main Air Jet: 200 Pilot Jet: 60 Pump Nozzle: 0.45 I was able to find one member on here who ran a similar set up with a bone stock N42 block/internals 20+ years ago. He ran a 145 main jet. However, I was not able to find out what size his air correctors were. Any suggestions on baseline jet settings for a set up like this? Or am I just on my own with my O2 sensor analysis? I have included pictures for you! Please excuse the mess, it's still under construction. Thanks in advance!

Hey all I just picked up this Mikuni manifold and was wondering what these normally sell for. I have searched around and I couldn't find much info on these manifolds, just that for a short time Mikuni produced these along with their 44's as a package deal. Thanks for any info

Looking for a set of triples. Whether full package or just parts. I’ve found a few sets on eBay, Redline being one of them, and those are a little out of my budget right now. Just curious what else is out there. Thanks, -Dean

Nearly complete with my Mikuni 44PPH restoration but in search of the final piece. I believe these are the stock velocity stacks but I could be wrong, I have 5 that are in good shape and 1 that is completely destroyed. Looking for 1 air horn to match the set (don't feel like spending $300+ on a whole new set just yet) Basic dimensions are: Carb matting side diameter: 48mm Open air side diameter: ~78mm Height: 50mm If you have more than 1 available I would be interested in picking up extra as well.

I have been having so many issues tuning my triple OER/SK dcoe 40 carbs. I recently bought these carbs secondhand. I have been running into issues with idle speed, and synchronizing. The car runs very rough and the engine shakes quite a bit. Problem #1 I attempted to synchronize all three of the carbs but ran into many issues. The carb (#2) in the middle seems to be drawing in a lot of air compared to the carb (#1) and carb (#3). This is with all the carbs set to the same idle speed screw distances. I suspect that carb #2 has a bent throttle shaft or butterfly, but the butterfly opens smoothly with no obstructions. I also checked for vacuum leaks and there doesn't seem to be any. Problem #2 When I put the synchronize tool onto any of the carbs the idle drops and the carb drools fuel everywhere, like a toddler drooling. I am not sure if that is normal or not. Every carb seems to do that when I hold the tool up to the throat. Also when I hold up the sync tool to carb#2 the engine almost dies out. Desperately, trying to find a solution I have to increase the idle speed of #1 and #3 in order to match the flow of #2. This resulted in a super high idle speed of about 2000rpm. Problem #3 Carb #2 seems to also be running much leaner than the others. I had to turn the idle mixture screws a few more turns than #1 and #3. please any advice is welcome.

So with fall right around the corner, I'm preparing another small, and maybe final batch of Mikuni/Solex carb hoodies. This is a very small batch, with only 5 available in each size. The hoodies are made by Gildan, here are the specs: 8.0-ounce, 50/50 cotton/poly; no pill Air Jet Spun Yarn Double-needle stitching Double-lined hood with dyed-to-match drawcord Set-in sleeves Rib knit cuffs and waistband with spandex Front pouch pocket The hoodies will be ready to ship the second week of September. Typical price is $30, pre-order group buy price is $24.99! You can pre-order via hybrid-z or directly through the store.

I'll stick this here knowing the subject has probably been beat to death already. Recently rebuilt mikuni 44phh carbs and added a Schneider 270-80f cam to E88 head, 2.6l block. Fuel pressure is at 3.5psi. The car started a little rough with a lot of backfire through the carb. I thought of the dizzy being 180 out but confirmed it wasn't. I have start to play around with advancing the timing. Initially it was idling at 0deg and rough, 2-3000rpm would hit 15-18deg and smooth out the roughness. Fuel pressure is at 3.5psi. I currently have the: Mikuni pilot screws are all out 1.5 turns. Idle sitting 1000rpm 15 advance at idle 2-3000rpm advance is probably at 30deg (off the scale) Still getting backfire through carbs particularly on cylinder 1 at idle. Next steps tonight are too sync the carbs, adjust with the idle on backfiring carbs - am I missing anything? I've attached an idle video and picture of jet sizes. Any input or comments would be helpful.

I am looking for a complete 45mm triple carb setup with the manifold and linkage. The condition be can be whatever if the price is right. Keep in mind a brand new set of Webers from MSA is $1,650.00 so I am looking for a cheaper price than this.

Background: Long story short, wasn't interested in cars until I got screwed over by a dealership replacing an alternator shortly after moving to Maine from Ireland. Found a '84 300zx for $300 on Craig's and proceeded to teach myself the dark arts of car wrenching, and consequently fell in love with Z cars/Group B/Rally/Hillclimbing Fast forward a few years, I picked up a 1970 240z with some track prep work done and it begun: Cars 1970 240z: 2.6l engine Mikuni ph44 carbs Battery relocate. MSD Ignition Rota Grids with Toyo Proxxes Put cosmetic (Flat Black paint), small amount of mechanical work (New clutch, relined tank, new Holley Red FP, FR, SS lines) and new shoes on the car to prep for the New England Hillclimb Association 2015 season. Work and life got the better of me and only got to one race. Car performed pretty good and the driver got a lot better over the weekend. Couple of issues raised their heads over the race weekend: Keeps popping out of second gear. Power-band not right. 1st, 2nd great to 6500rpm, go to 3rd and bogs down bad. Last two races, kept stalling in low rpm and overheating - I believe this was from running out of fuel and picking up something in the carb. Need a full roll cage if I keep racing it; wife and kids agree. The last bullet is how I happened upon the 280z. After pricing a cage and always being on the hunt for a deal I came across this 1976 280z in a wrecker yard in MA. Something caught my eye on the Craig's post - I had been lurking on Hybridz for many years and thought had seen the chassis before. Upon viewing it was indeed one of RB240zDET's builds. I was able to get the car and good price and figure the project would be worth my time. 1976 280z - as it stands: Tubular frame chassis. R33 rear subframe and R230 diff. RB20DET engine mated to GTS trans. Lexus SC400 front end. Probably a bunch more I have yet to document. Link to PO frame build thread: http://forums.hybridz.org/topic/102035-rbs-builds/ Link to RB20DET PO: http://forums.hybridz.org/topic/94498-just-a-few-pics-of-what-i-have-been-up-to/ Current Winter Plans: 1970 240z - Clutch fan delete./Install aluminum rad and dual fan setup. Find a 5-speed (Anyone got one?) More aggressive cam for hillclimb racing Carb rebuild New fuel cell and sender install. Go racing 1976 280z - Verify and finish engine wiring. Get engine to run or at least show some life. Pull said engine and trans. While deciding if to keep engine or not; fix some weld, blast frame and prime. Select engine. (Open to offers on the RB20DET if anyone is interested.) Build monster. Go racing. Garage - 100A Subpanel 5kw Heater. 40A circuit 208v for welder. A few 20A 110v circuits. Insulation Sheetrock Paint Some sort of shelving system for organization. Any comments, suggestions, critique is welcome. Seán

I am on the search for a complete set of use-able / rebuild-able triple DCOE carburetors. Either 45mm Weber's or 44mm Mikunis is what I'm looking for. I would need everything to install into a 280z with an L28. Can work on trades as well, please see my for sale posting.

I am putting together a set of three and would like to find one parts carb with a good body. Prefer to spend $150 ish... so missing parts ok! If you think you have what I am looking for, please reply with pics in post. Thanks in advance. Garrett

Recently replaced my fuel system on 70 240z. Started it back up last night after a few months of been idle. Started up a little lackluster but nothing uncommon. After two minutes of rough idle the carbs started to stutter or burble. I'm adding links to the youtube clips I took. I didn't run the engine for much longer just incase. Fuel system: tank - filter - pump - regulator - manifold - carb - carb - carb. Any thoughts? https://youtu.be/holqzub_U8w https://youtu.be/UyFgPYs0-fA

I've been doing some tuning of my Mikuni 44 set up as of late with the assistance of a wide band o2 sensor, and I have learned a few things that may be helpful to some others. Generally, I recommend determining these in the order listed: Pilot Screws: One bit from Honsowetz in the How to Modify Your Nissan Datsun OHC Engine which is a very specific instruction: run your pilot screws 1.5 turns out. I have mine set at 1.5 dead on, and the engine likes the 57.5 pilots at that setting. AFRs are where they should be for idle and low speed operation. The engine runs well in both of these conditions. Mains (Fuel Jets) and Air Correction (Air Jets): This bit came from TonyD... and that is stay out of the pump nozzles when trying to determine what the engine wants for main and air jets. Accelerator pedal movement may engage the pump circuit and if it does, this will throw fuel into the mix from that circuit. This will "mask" what is happening with the main circuit and you won't know what is what. According to the Mikuni manual, accel pumps are in play from 0 to 30% of throttle. So use inputs like 50% or 100% and ignore where the 0-30% is most likely occurring. Since the pump circuit has a known volume... and the duration of the fuel "injection" from the nozzle is specific to each nozzle, you could time the length of the injection duration if you are so inclined. Then you could ignore that time duration (from throttle open) in your Wideband AFR (Air Fuel Ratio) plots. Pump Nozzles: This one came from my engine builder. Know that sometimes wideband o2 sensors/loggers may show you rich readings when actually the engine is lean. This can occur when there is any engine misfire condition. The rich reading is resulting from a chain event of the flame going out too early, and the subsequent passing of remaining unburnt mixture through to the sensor. When you open the throttle quickly, if the engine is sluggish, but doesn't misfire, and your wideband shows rich, you are rich. However, if the engine misfires, and your wideband shows rich, you could be lean. Regarding this last one, I think that is what I am currently experiencing. I will be testing that theory out soon. As I have changed the pump nozzles from 50 to 45 to 40, I am fairly certain that I have been experiencing a more prevalent misfire when applying large throttle inputs (I haven't been doing much full throttle yet and there has been a fair amount of time involved from when I swapped nozzles one to the next to the last). I was going smaller and smaller because of the rich readings I was getting on the wideband when "throwing large throttle inputs" at the engine. Last tuning session, I was getting a large amount of misfire for the first couple of seconds of full throttle... even when in first gear. I am going to switch back to the 50's next and see if that situation improves.

I'm in need of a few Mikuni 40PHH type-R parts: outer venturi's (32) Turnbuckles (Ball End) (Adj. 102-117MM) - they are the linkage arms that come down off of the balance rod Any S30 ('72) linkage for the Mikuni short-runner

Like the tittle says, i'm looking for a cannon or similar manifold. Please PM me here and we can work something out. Thanks! -Antonio

Looking to buy a set of 3 matched Mikuni phh 44 carbs. Doesn't bother me if they are type S4 or S5. Either type will suit me and my needs. If seller has manifold as well this will be great. Pm me or email at onemorekay@gmail.com