Everything posted by 240260280z
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SU Bridge Evolution: Round Top vs. Flat Top (Comments welcome)
We will find out.... with data over the next month or two.... Tony D already knows. I presently am planning a "diluting circuit" for a round top to make it a 2 stage carb... an accelerator circuit would just be needed to make it 3....thinking on that now. The fact the 2nd gen also draws fuel lower in the throat (like a British racing mod), it has a narrower throat (like Mikuni bike CV ), a big fuel bowl sits right under the bridge, and the fact its bridge geometry is much different means that it was changed for either performance, fuel efficiency, emissions, reduced manufacturing costs, or a combination. As mentioned, exploration, data gathering and comparisons are needed. There are many other interesting differences that will be shared too. Remember that Nissan engineers seemed to always fight emissions performance losses that hurt the base L24 building block by increasing horse power (stroke & bore) so it is reasonable to assume they also looked elsewhere for improvements. Probably heard in the halls of Nissan HQ in the early 70's: Engineer "The !$^& US pollution and safety regulations are turning the car into a fat lazy pig." Bean Counter "If the power disappears, the customers will disappear and we will disappear." Boss "Work the problem and give me solutions."
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SU Bridge Evolution: Round Top vs. Flat Top (Comments welcome)
Weird, let me see if I can fix. How is that now?
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Spent the day with a flat top expert and learned a lot.
I missed the fact the this forum does not convert file names to numbers... you hit it out of the park Yup it is a flat top jet that is normally well secured deep inside a flat top SU. It only sees light through the fuel bowl window. My new Z friend showed me a great deal of flat-top details today including a cool tool he made to safely remove the jet,
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Spent the day with a flat top expert and learned a lot.
Sir: Strike 1
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SU Bridge Evolution: Round Top vs. Flat Top (Comments welcome)
Top view looking down piston bore (flat top is on right) Flat top: Bridge is wider (front to back). Jet sleeve is fixed and jet depth is set to correct height in factory (no choke up/down movement). Front and rear ramps are different geometry. Piston diameter is smaller Has 3 circuits Main (jet and needle like in a round top) Choke (see the small forward spraying nozzle upstream of main jet) Power Valve (off idle transient to WOT...see the hole on right side of ramp at back of bridge) Has air bypass around main jet for setting idle mixture. Has integrated fuel bowl below jet. Front view looking into throat (flat top is on right) Flat top: Bridge is lower in throat. No stepped edge on front of bridge. It blends into ramp. Choke nozzle is seen in foreground in front of main jet protruding from the floor. Floor of throat from front of carb blends into ramp. Choke valve (in open position) is seen in foreground near top. Tube bringing ambient air to push up on piston is seen in foreground on right. Rear view looking into carb (flat top is on right) Flat top: Bridge is lower in throat. Higher vertical dropping edge "cliff" at back of bridge Narrower vertical dropping edge Rear edge of bridge is further back in carb and closer to throttle valve Power valve fuel outlet is seen as hole on lower right of photo below the bridge level. Idle air outlet is as hole on middle right of photo above the PV fuel outlet. Bushing for throttle valve (removed) is seen on side wall of throat
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Spent the day with a flat top expert and learned a lot.
Made a new Z friend only 45mi away in Pa. Had a very nice drive through beautiful Pa. and lunch. Spent the day talking carbs and geek stuff... a blast! Learned a lot. Also planning research collaborations too. Stay tuned to this channel. P.S. How many of you have ever seen this item that rarely sees the light of day except through a window? Tony D you are not allowed to comment
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Alternative or source for cowl drain grommet?
Thanks a million guys! Gee Dan and Jim wow thanks! Yes I'll gladly take two... I'll pester Jim and he is a long time buddy. I'll pm you. Philip
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front control arms and bushings
http://atlanticz.ca/zclub/techtips/suspension/frontcontrolarm/index.html
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Quick question about hatch strut
There is one you can get from Autozone that is supposed to work with minor mods. I have one but never had a chance to try it. http://www.autozone.com/autozone/parts/Mighty-Lift-Support-Lifts/1971-Nissan-Datsun-240Z/_/N-iq2l9Z8ii2g?counter=0&filterByKeyWord=hatch+strut&fromString=search&itemIdentifier=193495_3214_2819_
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Hurricane Irene
The weathermen missed it.... it was not the wind but rather the rain that caused the problems. The media was in NYC and along the coast waiting for the wind and hyping fear when at the same 100 to 200 miles inland, the deluge that all missed except the poor folks hit by it without warning.... shame on the meteorologists and press.... they missed it completely.
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SU Mod (lifted from the net)
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SU Mod (lifted from the net)
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SU Mod (lifted from the net)
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SU Mod (lifted from the net)
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SU Mod (lifted from the net)
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SU Mixture Question
It has a DC output for logging. I am not sure of the sampling rate, hysteresis or DtoA details but can find out. I am playing with this AtoD to make a flow bench. We can talk about it on Monday http://www.vellemanusa.com/us/enu/product/view/?id=500349
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Alternative or source for cowl drain grommet?
I'l like to put new grommets in the 71 240z I am restoring. Any suggestions? What is hole size? (I am thinking this may work):http://www.datsunparts.com/2371
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Dimples circa 2003
http://www.circletrack.com/enginetech/ctrp_0309_race_engine_airflow/viewall.html
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[2011] What did you do to/with your S30 today?
It is a proven power gain by Norm on Zcar.com! Looks beautiful too! Cut some baby stacking rings in half and fix to the opening inside the filter for improved air flow or use the horns from the orange one.
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Electrical Issue?
My apology and correction, the wires were not damaged by the fan, it was damaged by a pulley (back in 2007). Here is a photo of the damage:
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Electrical Issue?
I would guess that a wire between the distributor and the coil/ballast may have come loose or broke when the SU work was done. A friend's 260z would randomly die and it turned out to be an exposed wire from the distributor that had it's insulation damaged by the fan and it would intermittently be blown by the fan wind when driving and short to the metal in the area and kill the ignition system. You seem to have a similar strange happening. Check the low voltage wiring closely at the distributor/fan area.
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Strong fuel smell in the car when I turn LEFT
check this out: http://www.classiczcars.com/forums/showthread.php?25857-Rating-the-factory-240Z-fuel-vent-hoses
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SU Mixture Question
Innovate LM-1 In the cabin: Innovate LM-1 crudely attached to the exhaust using a broken pipe and steel wire: Correct pickup: The 260z:
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Ideas on cleaning up the engine compartment?
Glad to help that beautiful car of yours!
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Ideas on cleaning up the engine compartment?
Some ideas: 1. Balance Tube: grind, then weld with aluminum then polish or grind, jb weld, smooth then paint as you suggested. Or get an early 240z balance tube. 2. For air filter, stretch a nylon sock over the mouth For your fuel lines: Run the fuel lines below the carbs. Use a straight piece of polished steel or aluminum line for most of the fuel line run with rubber at the ends for convenient connections relocate the fuel filter between the pump and the tank For your plug wires: dress the plug wires around the front of the motor