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djwarner

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djwarner last won the day on August 13 2016

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About djwarner

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    HLS30A 17574

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    Central FLorida

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My Z Cars

  • Zcars Owned
    240z
  • About My Cars
    1971 240Z HLS30A 17574 L24-021025
  1. 4 bolt su carbs

    Sorry the spread sheet I have for the various distributors did not have the complete specs but it still has useful information for you. The d6k8-22 was used on the 1980 ZX for both the AT and MT. Static timing (0 RPM) is 10 degrees. Centrifugal advance is a max of 17 degrees at 2500 RPM. So as you are setting timing, set the 2500 RPM to 27 degrees BTDC and let the idle timing fall where it may. I've checked many of the early dissy's and they all max out around 27-28 degrees without vacuum connected. It also mentioned that the Vacuum advance may range up to an additional 30 degrees and may thus be harmful. This is a function of how your vacuum port for the dissy is set up. On Weber carbs, the port only sees vacuum when decelerating like when you suddenly close the throttle. With an AT, if you are not getting stumbling when you quickly close the throttle, I wouldn't worry about leaving it disconnected. Again, without fuel injection, there is no idle speed compensation. Standard method is to set the idle speed with a warm engine in gear and let the idle speed in neutral fall where it may.
  2. 4 bolt su carbs

    Idle speed should always be measured with the car in drive with a warm engine. Idle speed in Park will always be higher. This is normal for carb'ed engines that don't have engine speed controlled by an ECU. 17 degrees advance at what RPM? These distributors are into centrifugal advance at idle speeds and timing will shift at different RPMs. Sorry, I don't have my manuals with me at present, if you can get the model number off the distributor, I can give you the centrifugal and vacuum advance particulars. The point timing specs listed in the FSM are measured at zero rpm (hence no centrifugal or vacuum advances) with a test light. BTW SU carbs don't really have a choke per se, the choke lever enriches the mixture. Once the engine warms for awhile closing the choke leans the mixture. I have a ZX dissy with an OEM ignition module and they have the equivalent of dual points as well. Though yours with an MSD ignition may have bypassed them.
  3. 4 bolt su carbs

    Nope, this is not a transmission related issue. ATs have a dual point system that retards the spark in cold temperature. However the sensor is in the passenger compartment and only affects the timing at temperatures below 40 degrees. I don't think you northerners are seeing temperatures that cold this early in the season. For AT's the idle is set while warm and in gear. Rpms raise when moving from drive to neutral or park as the engine unloads. A 250 rpm rise in that case would be normal. Start the cold car and after a minute of idling note the idle RPM in park with the choke off. Drive the car to let the engine achieve operating normal temperature. Park the car and note the idle RPM in park. If you are seeing an increase, the mixture is changing, the throttle setting is changing, or a leak has changed the vacuum advance. I would suspect a vacuum leak. If the leak occurs when the engine is cold and seals as the engine warms, I would expect the cold idle RPM to be low. This is contrary to Kully's description. I could see this happening if there was a vacuum leak at one carb that caused it to go lean when cold. If the leak develops as the engine warms, the mixture leans out. Since the idle is high when warm, it makes me wonder what conditions were when the last time the mixture and idle settings were done. BTW I have found that these engines never idled well at the "650 rpm" in Drive as specified. This worked well for 510's but not our Z's. I suggest the following: 1. Check the carb mount bolts for tightness as well as the balance tube fittings and intake manifold bolts. 2. Remove the vacuum advance line from the distributor and block it with a golf tee. 3. With a warm engine in neutral, set the idle speed to 900 RPM and set the timing to 10 degree BTDC. Idle speed will be affected as you adjust the timing, so you may have to repeat this step several times. 4. With a warm engine in neutral and correct timing, adjust the carb mixtures per the manual. 5. With the car chocked and the parking brake applied, set the idle speed to 700-750 rpm. 6. With the car back in neutral, re-install the vacuum advance line. If the idle RPM changes significantly, troubleshoot. Vacuum advance should only affect timing when letting your foot of the accelerator at high speed. I suspect that if your problem remains after this, the symptoms will change to a lower RPM at cold idle in drive. This may require more choke usage til warmed up.
  4. irma

    Out of curiosity were the arc marks on the half of the wire connected to the house or the pole? My understanding is that the steel cable provides the strength of the connection between the pole and the house and mechanically supports the copper wires. As a matter of safety, lightning strikes, etc., the cable is connected to the local earth ground at the house. If this is the case I would expect the arc marks to be on the half connected to the house. I went to check mine today but my service is underground.
  5. irma

    Appears you lucked out as well. Note on your electricity, your electric service is 220v made from two 110 volt circuits setup back to back. In your distribution panel each circuits feeds different 110V circuit breakers. Your 220V service has two breakers tied together each fed by one of the two 110V circuits. If one 110V power feed is down, you should have several circuit breakers without power, not just the 220V service. If all your 110V circuits breakers have power, then you have 220V service to your house and one of the two circuit breakers in your AC circuit has tripped. Try resetting the breaker. If some of your 110V circuits are out of power, it may be wise to flip off all your 220V breakers until power is restored to prevent stress on those loads.
  6. irma

    Our friends in Miami got it worse than we did in Central FL. I got less damage than Dave. Just lost a few plants.
  7. Surprised to see this thread pop up again. After being unable to find a reasonable rolling chassis, I decided to transplant the LFX/6L50 into a 2011 hardtop convertible Miata. I chose this venue because the NC Miata could accept the engine and drivetrain with little to no body alterations. While others have mounted the LFX into Miatas with 6 speed manual trannys, This will be the first with an AT. Weight will be within 200 lbs of stock 240Z. Compared to the LS installations from Flying Miata that require serious tunnel modification, the bodywork for the NC model was a piece of cake. V8Roadsters sells mounts, half shafts, drive shafts etc for the swap. They also sell a shortened oil pan, though it is not required for this installation. So far I have the engine/tranny/diff installed. While the engine bay in the 240Z is enormous, the Miata was a tight fit. I had to slightly relieve (ball peen hammer) the firewall near gas pedal mount and trim some clearance on the passenger front frame rail. Also had to widen the tunnel to clear the shift linkage again ball peen hammer). Also had to remove a minor front cross brace ahead of the of the engine. Currently working on a new power steering pump bracket (version 2.0) and modifying the steering linkage to work around the exhaust downpipe. Because of the tight fit and the water pump being mounted on the rear of the engine, I had to substitute the heater lines and radiator feed tube from a Cadillac CTS. Seems this engine has been used in a number of GM apps in both transverse mount and longitudinal mounts so lots of accessory parts are available. Work is coming along.
  8. Engine time

    If there has been a catastrophic failure, It was probably only one cylinder and should be pretty easy to isolate by examining the plugs without running engine. Obviously oil is getting into the cylinder(s) to be passed to the exhaust or a leak from a valve guide or cracked head. Clean plugs would point to the head. Inspection cameras are getting to be fairly cheap. You might consider picking one up at Harbor Freight and examining the pistons through the sparkplug holes.
  9. What would cause a noisy spark plug ?

    My guess is a loose or cracked insulator.
  10. Draw through carb turbo setup

    aah, Google is a friend of mine. Here is the link to the FI conversion kits http://www.pattonmachine.com/index.htm
  11. Draw through carb turbo setup

    This is an interesting configuration. The first version of this configuration I ever saw was in the '64 Chevy Corvair. It even got a special write up in the Popular Science. The advantage of this configuration is the ability to use a standard carburetor with the float chamber vented to the air. Placing the turbo ahead of the carb requires the float chamber vented to the pressurized carb inlet. There is a guy selling a FI conversion system that bolts onto the SU carbs but Windows 10 wiped out my link to it in my favorites. Maybe another member has the link.
  12. After 4 years, it has come time to move on to another project and so my Series I AT is up for sale. http://www.streetsideclassics.com/vehicles/0859-tpa/1970-datsun-240z The consignment shop hasn't put all the details of the car on their listing yet, so let me list some particulars here. Built in December 1970, it is a true Series I car but was titled in '71 and is a rust free matching numbers car with Vintage Air AC. I have reconditioned the drive train from stem to stern. Engine was overhauled about 5,000 miles ago including rings, bearings, seals, timing gear, oil pump, OEM cam shaft and starter. Engine uses no oil and pulls full compression and manifold vacuum. SU carbs were replaced with downdraft Webers by a previous owner. I have converted them from sequential 2 barrels to synchronous operation with a kit from Redline. I also re-jetted the carbs for proper operation with our modern fuels. Ignition is a solid state module from a '78 Z. I am including a set of 4 screw SU carbs with the car if someone wants to restore it to the original configuration. Transmission was replaced with one from a '78 Z (was told it had 82K miles on it). Differential was rebuilt. Struts were replaced KYB units. Brakes rebuilt all the way around. Wheel bearings were replaced all around. Universal joints and bushings were replaced as required. Headlamps are LEDs with relay wiring. Instruments have supplemental LED lighting added. Radio is a modern HD radio. Dash is solid with no cracks and is wrapped in Italian leather. Mags are 6 hole American Dragmaster. Spare is an OEM steel wheel and holds air. I have spent time to make this car ready to be driven and enjoyed daily and have put 30,000+ miles on it over the last 4 years.
  13. A few honest questions about vapor lock

    Just an update. Ran wire for the electric pump into the cockpit and dived into the area behind the radio to repair the defroster circuitry. After figuring our where to tap the power, I located the switch on the bottom of the steering column plastic finisher. Plugged the battery back in and the pump ran as expected, but when I went to start the engine, the starter circuit was dead. Finally traced the problem back to the neutral/park switch wiring (AT). While running the wire for the pump, I must have loosened a bullet joint. With the old style soft plastic tubing over the joint, nothing was apparent until I tugged on it. So back to testing the pump. Earlier in the day I ran the pump until I heard the change in pitch as the fuel manifold pressurized and then another 5-10 seconds. So several hours later when I got the engine to turn over, it started in the first second of cranking with no choke applied! Looks like I got a winner. Thinking back to how long it takes to pressurize the manifold, I wonder if the check valves in the engine driven pump may be allowing fuel to slowly drain back into the tank leaving air/vapor in the fuel manifold. An empty manifold could be a partial cause in the delay to re-fill the float bowls after sitting for several days. In any case, the electric pump seems to be doing the trick.
  14. A few honest questions about vapor lock

    Very interesting reading Mark. The major difference with the later 240's and 260's from the earlier models was pollution control requirements. The fact that Nissan was able to meet new regulations and improve performance over the '70s is a testament to their efforts. So there was a competition hood with side vents.
  15. In five years in Florida I've yet to experience vapor lock in my Weber down draft equipped 240Z. So my question maybe more academic curiosity raised while I was working on a different problem. My problem has to do with hard starting after my car sits for several days. I can't say I ever experienced starting problems when it served as my daily driver. Now that I've moved on to others projects, the Z often sits for 3-5 days without starting and hard starting has raised its head. At first I thought I caused it when I converted the sequential 2 barrels into synchronous operation with a kit from Redline. Also I re-jetted the carbs to better handle the ethanol laced gas we all suffer with today. I suspected the conversion kit because it lacked the device that cracked the carbs open when the choke is applied. It got to the point that a shot of ether was required to start after 3 days of sitting. Cold starting the next day required no choke, second day required half choke, and third day ether. I believe I have finally traced it down to evaporation through the float bowl vent. This causes lean mixture until the bowl finally refills. This requires enough pumping from the mechanical pump to raise the fuel manifold pressure and fuel to pass through to the float valve. Getting volume through the mechanical pump is not a problem with a slowly cranking engine, but achieving pressure is another matter. The first owner had been talked into replacing a defective mechanical fuel pump with an electric pump mounted back near the fuel tank. The second owner decided he didn't like the clicking noise and went back to an engine driven pump. He didn't bother removing the electric pump, just plumbed around it and sealed the electrical pump by connecting tubing from the inlet to outlet. He also disconnected the power lead. I subsequently removed it during other maintenance. It occurred to me that it might be useful as an on demand booster pump to refill the float bowls. After cleaning and replacing its fuel filter, it checked out, so I installed it yesterday. Verifying it would work inline with the engine driven pump, I removed the rubber return line at the metal line on the fuel manifold. Holding a glass to the metal line, I turned on the pump. At first I got the familiar clickety-clack as the air was purged from the line. Then the pump quieted down as the pressure began to build. Success. It was then that I realized why the Z never required a fuel pressure regulator. The fuel passing out of the return line was a much thinner stream than the diameter of the rubber line that connected to it. Aha! a closer examination showed there was a restrictor on the end of the metal line with a small hole, perhaps 1mm in diameter. This small hole established a pressure drop and this pressure was presented throughout the fuel manifold and up to the float valves. So when the engine is cranking before start, the pulse rate of fuel from the pump is much slower that an idling engine and the pressure is never generated. So any stickiness at the float bowl valve - or in my case - restriction caused by adjustment of the float height means that the ability to re-fill the bowl is greatly diminished. Since the electric pump has the ability to supply pressure and flow rates for max HP without regard to engine rpm, this should be an acceptable solution and I will install a momentary switch near the console. (REDLINE changed the recommended float height to accommodate modern fuels with ethanol. I did this when I re-jetted the carbs.) This has got me thinking about vapor lock. If the return line is always open through this orifice, how does vapor prevent flow of gas to the carbs? The only way vapors can disrupt fuel flow is for vapor to get into the check valves in the engine driven pump. If the check valves don't seal vapor well, no net flow of fuel occurs. I have heard it said that is pressure builds in the fuel rails, it can pass to the float bowl causing rich running. But my carbs have float bowls vented to atmosphere and any pressure in the fuel manifold will simply vent through the return line. If I am right, there would appear to be little to no advantage in wrapping insulation on the fuel manifold metal lines as is often done. While shielding to prevent heat from reaching the float bowls and vaporizing the fuel there would appear worthwhile. So what have I got wrong?
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