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Nigel

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Posts posted by Nigel

    The flutters!

    in MegaSquirt

    Posted

    I didn't have any problems with fluttering (chirping noise, bouncing boost gauge, bucking, running too rich) until after I installed my intercooler. I guess it has to do with the added volume of the intercooler. Part throttle boost is impossible now. It starts fluttering badly if I try to hold a steady boost level, and I either have to back right off, or put my foot into it. There's nothing in between. In fact, now it will start to flutter before I even get positive manifold pressure.

     

    You can hear it clearly in the video linked below. Mine is the second car that drives by. I put my foot into it as I approached the camera, boosting to maybe 7 or 8 psi, and then backed off slightly just as I reached the camera...

     

     

    Nigel

    '73 240ZT

    Interior raw gas fumes

    in S30 Series - 240z, 260z, 280z

    Posted

    Holy C**p I took the right rear plastic panel off to access the overflow tank. What a maze of tubes! That being said, all of the hoses look to

    be OK with the exception of the grommets that seal the hoses that go

    from the rear deck to under the deck.

    Could these grommets allow gas vapor into the interior?

    thanks

     

    Just because the hoses "look" ok, and the clamps may be tight, the rubber can be so old and dried out that it no longer seals on the hose nipple...

     

    Nigel

    '73 240ZT

    300zxt cv conversion problem (on a 72 240z)

    in Drivetrain

    Posted

    I HAVE read that the end caps need to be removed, and I believe I caught it in a passing mention in MM's advertising. I have yet to run on this setup, so I cannot attest. Can anyone else chime in? I'll obviously have to do some more research and interpolation.

     

    As I mentioned earlier, I'm running the Z31 CV's with the caps installed. But I'm not running the MM adapters. I still haven't been able to get dimensions on mine yet though...

     

    Nigel

    Fuel Pressure Drop When Hot

    in Fuel Delivery

    Posted

    Here's a thought! Don't circulate a lot of fuel. Design a system to hold Xpsi at the injectors that delivers the amount of fuel needed.

     

    Many modern cars use a returnless system, but I believe that's to combat the evaporative emissions issues due to returning hot fuel to the tank. Regardless, I don't see how this would help keep the fuel cooler. If anything, I would think that it would make fuel temps worse since the fuel is trapped. At least if it circulates, it has a chance to be cooled. You'd also end up with a fixed pressure system (not boost referenced), because the regulator would be back at the tank, and a vacuum line that long would be ineffective. Not the end of the world, but it could complicate tuning.

     

    I was thinking of something along the lines of a fuel rail cooler. Make a fuel rail with two lines though it, one for the fuel, and the other to pump water through, with it's own separate cooler, and a small water pump. You could use a small reservoir to allow for some expansion that the pump would feed off of.

     

    Nigel

    Fuel Pressure Drop When Hot

    in Fuel Delivery

    Posted

    "Nice Cool Gas Tank" only applies to after you fuel it from an underground tank.

    I have has heated fuel suction cavitation present out here when the tank level drops to 1/4 as the recirculation heats up the tank.

     

    Driving across the desert will have your tank at over 140 degrees in NO TIME!

     

    I took a Coleman Cooler, sized to hold a full 7# bag of ice, and made a 'cool can' for a 240 we drove up to vegas with...the bag would last about 2 hours of driving, and the water would be over 120F...same as the tank contents! Lower fuel levels just don't work as a heat sink. Even with a full tank, unless you cool the fuel on the way back to the tank it will start heating up.

     

    Just depends on the vapor characteristics of your fuel as to when it will cause flash-cavitation on the inlet of the pump. The high-speed electric pumps don't seem any less prone than the diaphragm pumps mounted to the block-even though they are usually much cooler, and nearer the fuel source.

     

    I'm having a big problem with this right now. When I start out in the morning, after the coolant temp stabilizes, my AFR's are around 13.5 to 1. The longer the engine runs for, and the lower my fuel tank gets, the leaner the AFR. I used to think that it was due to the placement of the air temp sensor in the engine bay resulting in an exaggerated air temp value that would cause the ECU to lean out the mixture. However, I moved the air temp sensor to the outlet of my intercooler, and only saw a slight improvement.

     

    It didn't occur to me until recently that it might be a fuel temperature issue. Last night I got to put that theory to the test. I got stuck in stop and go traffic for 40 minutes with a 1/4 tank of gas, and I watched my AFR's climb up to 16.5 to 1! Everything else was constant though (I just realized that I may not have looked at the fuel pressure gauge). The intake air temps matched ambient (30C), and coolant temps remained between 80 and 90C. So, the injectors were still firing for the same duration as they were when the AFR was 13.5 to 1 in the morning, but I was now seeing 16.5 to 1 on the gauge. When I arrived at my destination, I touched the fittings on my sump and they were almost too hot to touch, as was the tank itself.

     

    I have a 255lph pump, and with a 1/4 of a tank, that means that the fuel is being completely circulated every 3.5 minutes! There's no way it's going to have a chance to cool down at that rate, since it's doing nothing but pick up heat as it goes through the pump, along the transmission tunnel where it's near the exhaust, through the hot engine bay and back again. I realize now that I inadvertently made thing even worse at the beginning of this year by moving the return line from the top of the tank to the second fitting on my sump. No wonder my poor fuel pump is screaming by the end of a long drive!

     

    So, my plan is to insulate the fuel lines in the transmission tunnel, put heat shields around the exhaust, and space permitting, install coolers on both the feed and return lines.

     

    Nigel

    '73 240ZT

    240 with 5-speed, clutch not releasing

    in Drivetrain

    Posted

    Do you know for sure that the clutch in the '81 was factory original? The 225mm clutch comes in 2 depths. According to my '73 service manual, the diaphragm spring to flywheel height is between 43 to 45 mm. The '82 service manual has a spec of 33 to 35 mm. The 240mm clutch has a spec of 37.5 to 39.5 mm. So that would mean that the 240Z 225 mm clutch would have the shortest sleeve, followed by the 240mm clutch sleeve, and the 280ZX 225mm clutch sleeve would be the longest.

     

    Here's a link to a page that shows the 280ZX 225mm and 240mm sleeves...

     

    http://www.forgeracing.com/240z_race_car/

     

    Perhaps the '81 ZX had an early Z clutch installed which would have a sleeve too short to operate the new clutch you bought? What are the measurements that you took of the two clutches?

     

    Nigel

    '73 240ZT

    L6 Turbo Header Group Buy

    in Group Buys

    Posted

    What I'm trying to figure out is what T4 turbo was used when the header was built? Even if the header was used on a right hand drive car there still would be fender issues. Maybe a larger T4 would barely fit since it would be mounted slightly higher then the T3. The A/C hose and brake switch would need to be relocated as well.

     

    Like I said, maybe it was used with an on-center T4 turbine. Not sure how much extra clearance they provide though...

     

    Nigel

    L6 Turbo Header Group Buy

    in Group Buys

    Posted

    Yeah, that definitely needs to be moved up and back.

     

    Here's a couple of shots of a stock turbo next to my T3/T04B...

     

    tn_full_Image019jpg_Thumbnail1.jpg

     

    tn_full_Image020jpg_Thumbnail1.jpg

     

    I think most people with hybrid turbos are using the T04E compressor, which is even bigger! I don't want to have to bash my fender in, or rotate the engine to make this thing fit. Plus the turbine looks like it's pretty much touching the brake warning switch. The T04 turbine would never fit. In either case, the brake switch would have to be removed. Maybe this header was designed for an on-center T04 turbine?

     

    As for an equal length header, others have proven it can be done, but there's no way that the turbo is going be located anywhere close to the stock position.

     

    Regardless, it looks like there's room to move the flange to a more suitable location...

     

    Nigel

    L6 Turbo Header Group Buy

    in Group Buys

    Posted

    All things considered, that header looks like a pretty decent design. The only thing I would think might be worth while changing would be to have the wastegate tube exit from the bottom of the collector rather than from the side so that the exhaust from the number six runner doesn't have to do a near 180 deg turn...

     

    Nigel

    Side Vent Scoops

    in Body Kits & Paint

    Posted

    yet another great thing about canada that we cant do in the us....cause its not nice to the environment....damn tree huggers

     

    I don't want to turn this into a political thread, so let me just say that we're catching up...

     

    Nigel

    Side Vent Scoops

    in Body Kits & Paint

    Posted

    LOL I was just thinking the same thing... Is there any WORSE place to have your Z than in the ocean itself?

     

    It's a Canadian car! If it's survived this long up here, a few minutes in the surf ain't nuthing to worry about. Regular oil sprays keep the rust monster away...

     

    Nigel

    '73 240ZT

    Deleted Distributor--What to do with oil pump shaft?

    in Nissan L6 Forum

    Posted

    I've been looking into this too, a search didn't reveal much.

     

    I've seen what looks to be simple block off plates that replace the dizzy mount to one that I saw yesterday on a Supercharged L28 that had a nice block off plate just where the dizzy gets mounted for adjustment, on top of that little stand off.

     

    My concern is the shaft being able to move in a linear motion inline with the shaft, towards the dizzy. I haven't seen any pictures of how the dizzy/oil pump drive is installed and if it gets retained in a way to keep the shaft down, towards the oil pump.

     

    I don't know if you had a look at my Z on Sunday, but I'm using a 35mm freeze plug to block off the distributor hole. Simple and cheap! I've had that in there for 7 years with no problems. The bearing sleeve for the shaft is just above the crank and keeps the shaft from going anywhere. There's no need for any additional support where the distributor used to be.

     

    Nigel

    '73 240ZT

    Boost Question

    in Turbo / Supercharger

    Posted

    Sure, it will "hit" harder but that also delays feedback to your wastegate. If you have boost spike issues, running your wastegate signal on it's own hose directly from the compressor housing is one of the first things you should do.

    For most cars it won't hurt to do it either way.

     

    I datalogged both on my Z, using a Hallman MBC, and I can clearly see boost spikes with the wastegate signal from the manifold. With the wastegate signal from the turbo, it hits the set boost and holds it nice and steady.

     

    Nigel

    '73 240ZT

    300zxt cv conversion problem (on a 72 240z)

    in Drivetrain

    Posted

    I don't get why so many people are having problems. My shafts go in with no problems. In addition to flipping the outer cage, I too ground a bit of the end of the shaft leaving about 1/8" before the snap ring groove. But even without grinding the shaft, I think they'd still go in. And I am using the dust caps on the end of the joint. Mind you, my adapters were custom made by a friend of mine, who machined off the old flange and pressed, welded and pinned a new CNC'd flange on. But I can't imagine that the overall dimensions of the MM adapters are that much different. Strange...

     

    Nigel

    '73 240ZT

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