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Chickenman

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Everything posted by Chickenman

  1. I think you need to try a different Multimeter or change the batteries in that meter. Low batteries in a Multimeter throw off readings. Double check it with a different meter just to be sure. Lights sure a heck aren't going to go dim at a 16.6 charging voltage and a battery that supposedly measures 14.8 volts. High battery voltage will not " usually " cause an engine stumble either. In fact the coils will put out an even hotter spark. Only exception is if coil is old and weak and extra voltage heats up coil too much. That is a possibility, although rare. Also, if it was over charging that much, the battery case would be getting very hot and you would smell sulfuric acid fumes in the air from the Battery boiling off. Did you notice any of that?
  2. Note: One important thing regarding new fuel pumps. The original Nissan pump was a roller vane style. Those can pass a surprising amount of dirt and crud with minimal damage. However, most aftermarket pumps are now high efficiency Ceramic Turbine pumps. Thye can build more pressure and volume than a Roller Vane pump and are quieter. However, these Turbine style pumps ( Walpro, Bosch 040/044, Aeromotive, Airetx etc) have extremely close tolerances inside and will not tolerate ANY dirt. You absolutely must install a Fram G3 filter between the fuel tank and pump before running the pump. Failure to do so will result in scoring of the Turbine impeller and loss of pressure in very short order. Airtex has various technical articles on the different types of pumps, and why clean fuel is so important with the new style pumps.
  3. Just a thought... but if you are going to swap to Triples down the road, why don't you do things the easy way? Leave the stock ignition in place while you run the EFI, and install the MSD when you switch to carbs. Dead simple that way. The 1975 and 1976 Trignition boxes are pretty weak sauce, but the 77's and 78's are a bit stronger. If you want a stronger ignition, swap in a 79 280ZX Matchbox dizzy while you run the EFI?
  4. Edit: EFI ECU receives trigger signal from Coil negative terminal. You should be able to get a claen Trigger signal for the EFI by using the MSD Tach output. You may or may not need an MSD Tach adapter. Whatever you do, don't leave the OEM ECU/Tach trigger wire connected to the coil negative terminal with the MSD Box. You'll fry the EFI ECU in a microsecond. Triple carbs will make things much easier...
  5. That's the way I'd do it. The Dual pickup is an advantage in this scenario. As far as which wires to use to trigger the MSD, Use the Violet and Green wires hooked directly to the now isolated VR pickup in the dizzy. A Variable Reluctor pickup and a Magnetic Pickup are the same thing as far as Pickup signal for an MSD or Crane HI-6 ( CD ) ignition are concerned. Doesn't matter if you have a Flying magnet on a crank pulley or coil type reluctor in a dizzy. The output is the same and that is a modified Sine Wave. So you should be using the Violet and Green wires to trigger the MSD if you connect it directly to the pickup coil of the distributor. Note: If you use the Violet and Green wires you do NOT connect the MSD to any output signals from the OEM transistor ignition box. The Violet and Green wires must be connected directly to the VR sensor lead wires. Note that VR pickups are sensitive to Polarity. MS Manual gives advice on this. The White wire on MSD boxes are for Optical and Hall effect sensors. Those put out a square Sine Wave. Megasquirt has more info on pickup types. http://www.megamanual.com/ms2/pickups.htm
  6. After a long haul on the Freeway, I always pop the hood on all of my Cars ( Audi, Camaro, Datsun 280Z ) when I refuel. Lets all the stinkin' hot air out of the engine bay. After I refuel, I check the oil level, PS level etc etc, Then I'm on my way. Haven't had any Vapor Lock issues with any car since I adopted this procedure. Nice to give the engine a quick look over to make sure nothing is amiss.
  7. Not exactly Local. But well worth considering. Check out Specialty Engineering in Delta BC. Less than 2 hour trip fron Brier WA via the I5. The owner, Andy Pearson is a well known local Datsun expert. L -series are his " Specialty ". Top notch guy and builds SCCA National Championship engines and cars. Everything he does is first class. He's not cheap ( Nobody good is ) but the Canadian Dollar is taking a beating right now The weak Canadian dollar ( $1 cdn = .68cents USA ) can really make the trip worth while. And you can always go sking at Whistler for dirt cheap too!!! http://www.specialtyengineering.ca/
  8. ^ Agree 100% with Xnke's post above. He speaks the truth. Keep the CR below 10.5 to 1 ( Preferably 10.1 ) for Pump fuel. I live in BC and have a 1976 280Z with an F54 block ( standard bores ) and N47 Head ( not shaved ) running Flat Tops. That should give me around 10.3 to 10.5 to 1 CR. I've raced Datsuns and Chevies for many, many years. I would advise you to leave the head alone. For my 280Z, I run fairly conservative timing, 34 - 35 degrees total mechanical and absolutely have to run Chevron 94. At that I'm on the ragged edge, as I can sometimes detect slight pinging between 4,500 to 5,500 rpm. I also have a fairly big camshaft ( Shneider 280 ) so that helps lower Dynamic Compression. Datsun L-series heads, in general, are less tolerant of detonation than Chevy Aluminum heads. I had early Edelbrock RPM Aluminium Heads on my Hillclimb, Autocross, Track-Day car with a nicely 420HP 355 SBC. Those particular heads gave me a realistic 10.3 to 1 CR on a 355CI SBC. Car was Dyno'd at 360 RWHP and was a DD. Anyhoo... the Camaro, ( and other SBC's like it ) would tolerate a lot more Ignition Timing than a Datsun L-series ( with comparable CR ) on 91 or 94 Octane pump fuel without detonation..... so you really shouldn't compare the two to decide your Datsun's CR. It's Apples and Oranges. In BC, the guys running street cars on Pump gas try and keep NA L-series under 10.5 to 1. Anything higher and they can't get good enough fuel for it. Chevron 94 is usually the best for Hi Compression and Turbo cars. We can't get the Mohawk 94 Octane with 10% Ethanol anymore, ( thanks to Government Dick Heads ). That was sweet for Turbo cars. We also can't get Petro-Canada Ultra 94+ out West, which I hear is a bit better than the Chevron 94. And don't forget that if you take a trip South of the Border, the USA fuel is generally worse than ours as far as Octane quality. Their 93 and 94 Octane seem to be roughly equivalent to our 91 Octanes. So you'll have to de-tune your car some, by dialing out some ignition timing. And that's with CONSERVATIVE CR's. .
  9. Since I've got insomnia I may as well make one more comment. The Fidanza Aluminium flywheel could be causing a harmonics problem. I've had aluminium flywheels on various Road Race and Autocross cars with no issues. With one exception. A Fidanza Aluminium flywheel on a Audi Quatrro Autocross car. With a Turbo, AWD, 20 lbs boost and tall 1st gear, you often had to launch with a fair bit of clutch slip. This would sometimes set the Fidanza flywhell singing like wine glass rubbed with a finger. I've never encountered this before with any other brand ( Tilton, McCleod ) that I've used. Very strange. After some research it seems to be a design flaw in the Fidanza flywheel. It was just a bit too thin in a couple of places ( It's 9.5lbs ) and was prone to flex. Strengthening webs can also reduce vibration. But one of the interesting things was that a lightweight billet steel flywhell was often nearly as light as an Aluminium flywheel and reduced harmonics and vibration considerably. Possible food for thought. I completely agree that for Amateur Road Racers racers with a Budget, keeping the revs down is a very cost effective way to ensure engine reliability. Give me a choice between more Torque or more HP, and I'll take more torque every time. Looking at your gear ratio charts, if you build the 3.3 L I'd drop the rear end ratio some. 3.9's possibly instead of the 4.11's. Run the numbers. Concentrate more on a nice juicy flat Torque curve and less on absolute Maximum HP and high rpms's. If you're running the SCCA Runoffs and shooting for a National Championship... then build a Atomic Bomb if you have the cash. But for a Regional Road Racer or Track Day car, I prefer a big fat Torque curve with reasonable RPM range every time While an big displacement L-6 at very high RPM may sound so sweet... less sweet is the accompanying sound.... the " Ka-Ching " of the cash register!!
  10. One thing that bothered me when I looked at the photo's of the damage was the chamfering done to the crank oil holes. I've never seen oil hole chamfers that deep nor that large in diameter. Oil chamfers should just break the hard edge and be as shallow and small as possible. Have a look at some crank shafts on modern day high revving production motors such as the V-TECH series by Honda It rang a bell, so I quickly started grabbing some of my SBC and Datsun Engine building books. Sure enough, there was a picture of excessive chamfering on a SBC crankshaft ( very similar to what was done on your Crank ) with a warning from Smokey Yunick that excessive chamferring would cause a reduction in the Hydrostatic wedge and that was something that you definitely do NOT want. John Ligenfelter had the same warning. Yunick stated this " old school "method of crank prep was 10 years old and used in days of 50 wt oils and relatively low revs. That advice was given way back in 1979!! All that's needed for de-burring oil holes is a very slight radius round the oil hole. Just break the sharp edge. Enlarging the hole or ovalising the hole to feed " More " oil just reduces journal area and reduces the hydrostatic wedge. And it does NOT feed more oil to the journal. Have a look at modern day Nascar engines, Pro Stock, GT1, or LMP. Absolutely minimal radius around the oil holes ( and tight, tight bearing clearances... but that depends on journal design and size ). You absolutely must maintain that Hydrostatic wedge at all costs. I don't know if that contributed to the failure, but it probably didn't help. It's an area of crank preparation that I would defiantly change.... IMHO Edit: Jeez...how many times can I say " Hydrostatic Wedge ".... LOL
  11. I'm trying to find a link to the upper bearing support that our resident Machinist Guru fabricated. In the meantime, here is a link to a rather Famous car in the PNW. " The Bronze" Some wonderful fabrication skills here. Warning 66 pages long and still growing: http://www.the510realm.com/viewtopic.php?f=27&t=530 Edit: Finally found the link on the support bearing for the oil pump spindle: http://the510realm.com/viewtopic.php?p=55643#p55643
  12. You will still get shaft oscillations or " whirling " as engineers call it because of the long thing shaft that is unsupported at the distributor end. It doesn't matter how well supported the shaft is on the oil pump end, or in the timing cover. Without the support at the distributor end you will get oscillations, however slight, and that will eventually elongate the bushing in the Timing cover and then the oscillations will rapidly get worse and worse until you have a component failure. The L series oil pump spindle is by no means perfectly balanced because of the offset tang. The article below shows how critical balancing is on long shafts at medium or high speeds. This engineering paper explains the engineering problems associated with high speed shaft " Whirling" : https://www.google.com/search?q=Oscillation+in+high+speed+shafts&ie=utf-8&oe=utf-8
  13. Your RON Calculations to North American Octane ( R=M/2 ) looks about right. So you have good quality gas available. The simplistic curve you attached in the last post can be improved on a bit, but it's not bad. You don't need to Taper the final few degrees all the way to 8,000 RPM. Anything over about 3,700 to 4,000 RPM can be flat lined across the Axis. Assuming an idle speed of 1,000 rpm, which is good for a 270- 280 degree cam. Try this for 98 RON fuel. Note: This is a fairly sophisticated curve, taken from Tech Info from Haltech and 123. . The 200 RPM and 700 RPM set points are Optional and can be eliminated if not needed.... but it does help smooth things out. RPM BTDC Point 1: 200 10 ( Cranking RPM. Reduces load on starter ) Point 2: 700 15 ( Stabilizes idle and prevents stalling . Value = +2 over Idle Timing. ) Point 3: 1,000 13 ( Idle RPM ) Point 4: 1,200 14 ( Start of mechanical curve ) Point 5: 2,800 30 Point 6: 3,700 33 Point 7: 8,000 33 This will give you a very nice curve with good idle stability, a quick ramp up which is good for Torque and then the slow taper for the last few degrees to avoid detonation. 98 RON should handle this curve well. Note the higher timing figure at 600 RPM. This is to prevent stalling upon quick stops. Especially helpful in Autocross or if Air Conditioning kicks in. On cars without an IAC valve, ( Non EFI ) this is a simple method to stabilize idle. Keep this RPM set point figure set to approx +2 timing degrees more than idle timing degrees. After that you can take some Vacuum readings and let us know what they are and when they are stable. I do not know if your Weber 152's have built in Vacuum ports. Some do have ports for attaching Manometers to each barrel and some don't. The manometer ports are used for balancing carbs, but they can be used as a Vacuum source for other purposes. Edit: Important!! Always verify the programmed timing settings with a Timing light. How the distributor is " Physically " timed affects the total mechanical timing programmed in. ( 123's Website seems to have their Instruction links scattered all over the place ).
  14. ^ And of course Braaps article the NewZed linked to says essentially the same thing. Could have saved myself a lot of typing if I read it first
  15. Vacuum advance should always be used on a street driven car. It dramatically increases fuel economy. You can pick up an easy 4 - 5 MPG by using a Vacuum advancesytem properly dialed in. David Vizard has an excellent book called " Performance with Economy " where he explains the advantages of running Vacuum advance or " Load sensing " on a street driven car. Vacuum advance is the most mis-understood part of the Ignition system... mainly due to " Racers " saying you don't need it to make Power. And you don't... IF you drive at WOT all of the time...which race cars do and street cars do not. The vacuum advance pot works as a load sensing device and it really helps fuel economy. The reason being is that at part throttle and Cruise speeds, the mixture density ( Not to be confused with AFR ) is greatly reduced as is the " Dynamic " compression ratio. All this due to the reduced throttle angle. The low density mixture is much slower burning and needs to be ignited MUCH sooner in the OTTO cycle. With IR carbs running a Vacuum advance gets tricky because the vacuum source off of a runner fluctuates wildly and is very strong. You usually have to cobble together some sort of " accumulator " log manifold and pipe all cylinders together to smooth out the source vacuum pulses. And you often have to alter ( soften ) the spring tension if you have a big camshaft and may have to alter the travel length, However the 123 distributor makes things easier. Since you have a true MAP sensor and do not have to fiddlle with springs and stops in a Vacuum pot, you can set up a " Load " mapping very easily and take advantage of gaining some extra full mileage. Put a vacuum gauge on your car with a looooong hose and run the gauge inside the car so you can read it as you drive. It's better to have a passenger do this and record the numbers while you concentrate on driving. Try various cruise speeds that you would typically drive the car at. City and Hwy. You should find the the pulsing of the IR smooths out around 2,000 to 2,500 Max. Record your maximum vacuum readings. This is the start of your " Load Mapping " process. Now find a long hill and try some part throttle runs in various gears and throttle opening between 25% and 50% . Record the vacuum values. Anything above a certain level of throttle is going to show 0" vacuum. You don't really have to record this as it's the High Load section and will always be zero or close to it. Convert vacuum to Kilopascals or whatever your Programmer uses. Now plug in your numbers to the 2D or 3D cahrt. High vacuum vacuum = Low Load = more ignition timing required. Low vacuum = High Load = less or no extra timing required. All cars should safely handle an extra 10 degrees of Vacuum or Low Load advance. This is safe. Depending on parameters , " most " High Performance cars will safely handle 15 degrees of additional vacuum/load advance on top of the Mechanical curve. Some electronic Load Maps have a VERY nice feature called " No MAP idle " or similar. This switches off the MAP sensing corrections at idle, where vacuum readings can fluctuate with big camshafts or Independent runners until you get above a set RPM. usually around 2,000 RPM. Above 2,000 RPM, vacuum readings are normally stable enough for a MAP sensor to read reliably. Check to see if your 123 Ignition system has this feature. If so, enable it with an Independent Runner manifold ( or Big Camshaft ). Edit: It looks like the 123 Ignition does have a " No MAP Idle " feature. Check out the " MAP Start " box. That should be a minimum RPM setting to turn on MAP sensing. Sorry for the Novel... but I hope this helps some. Here's a link where I've used some personal Data to illustrate: http://www.the510realm.com/viewtopic.php?f=30&t=28374&start=15#p247318
  16. Need to know C/R, cam timing ( degrees ) and fuel quality. Assuming 93 - 94 Octane fuel, A C/R of around 10 to 1 and a Camshaft of 270 to 280 degrees. I find this has worked well for me over the years. 1: Static ( idle ) timing of 12 -14 degrees. Start curve 200 rpm above idle. 2: Total mechanical advance of 34 to 35 degrees ( depends on fuel ). Ramp up curve quickly to 30 - 32 degrees by 3,000 RPM 3: Taper final few degrees so that total mechanical advance is all in by 3,500 to 3,700. 4: For 91 Octane fuel knock a couple of degrees off all the settings.
  17. Looks beautiful. Are you using radius-ed trumpets inside the Plenum or flush mount? How much and when can I order one?
  18. What engine are you running? IDK??? Or more specifically, what lower thermostat housing? Stock 280Z ECU CTS thread size is M12 x 1.5mm.
  19. A very simple upgrade that is often overlooked, is an upgrade to a more powerfull " externally " regulated alternator from a 280Z ( 1975 thu 1977 would work . 1978 went to Internal Regulator). That would solve your electric fuel pump issue in a jiffy, as wiring is EXACTLY the same as factory 240Z. No " adapter " plug needed.. You can get these in 50 AMP and 60 AMP models. Cheap too if you know where to look. ( Haven't read Forum advertiser link policy fully ), but Google is your friend. Less than $60 for a 50 AMP and less than $90 for a 60 AMP. Nothing wrong with a " good " Mechanical external regulator. And thereare some Solid State external regulators available that eliminate the mechanical relays. Hard to find, but thye are out there. A buddy of mine hasbeen running a SolidStae external regulator with no issues for 15 years.
  20. Note: A lot of people call the all of the GM coils by the Generic name of " LS-1 ". But be aware that there are numerous versions of the " LS-x " series's coil. LS-1, LS2, LS-2 Truck/Yukon LS-3 and LS-7 coils etc. True LS-1 coils are the lowest output of the bunch, while LS-2 Truck/Yukon coils ( with Heatsink ) are the strongest. More important is that early LS-1 coils have a different wiring hookup than later coils. They use the same terminal as later coils ( LS-2, LS-3,LS-7 etc ) but the wiring order is different on the early LS-1 coils. Mega Squirt has wiring diagrams for both types of coils.
  21. PECX: LS-1 and all LS coils have built in ignition drivers. No additional module or ignition box is required. Coils are triggered directly from ECU via 5v trigger wire. LS-X coils are direct fire coils, which means you would run 1 coil per cylinder. My 76 280Z will be getting Haltech this winter. I picked up a used E-11. Still gathering parts. Have to locate Z31 chopper wheel.
  22. Just an FYI. Regarding coil wires and plug wires. Do NOT use solid core wires on any EFI engine. They generate a TON of EMI ( Electro Magnetic Interference ). You must use Spiral wound wires such as NGK, MSD Heli-Core or Magnacore. Even with Spiral core wires, you must keep sensor wires as far away as possible from HT Leads. And keep Hi power Ignition boxes like an MSD or Crane well, separated ( 3 feet or more ) from the ECU. Note how the factory put the ECU on the left pillar of the car and the Trignition box on the right pillar. The above is all documented in the Technical FAQ's of SDS, Mega Squirt and Haltech etc.
  23. Gets kind of hot up there on the Intake manifold due to the exhaust layout. Ignition coils should be located as far away from Exhaust heat as possible. I would consider a different location. Edit: Stock location is well thought out by factory and has a hole in Rad support that directs cooling air over the Ignition coil.
  24. What are you using for an ECU to drive the coils? I believe that you need to connect the Positive lead that previously connected to the coil to a Tach output or auxiliary ignition feed from your ECU. But I'm not 100% sure on that... This may vary for different ECU's ( MS, Haltech, AEM etc ), so those forums may have the answer if no one else chimes in.
  25. One of our local members , who is a machinist, was concerned about the effects of having the upper end of the spindle unsupported by the distributor collar. A good point actually. You have a long thin spindle and with the top end of the bushing being unsupported, you are going to get " whipping " oscillations that will eventually ovalize the bushing in the timing cover at the bottom. As this bushing gets more ovalized over time, the oscillations will become worse and worse. You could either cut the spindle just above the TC " support bushing" to minimize the shaft length and oscillation effects, or do what he did and fit a sealed ball bearing that slips over the shaft and locates in the upper dizzy support. You can then put a cover plate over that. There are various ways of doing this. Minor modifications to the dizzy support are needed and he made a collar to fit over the spindle, but a Lathe is about all you need. It made for a very neat and reliable install. I like the idea that the spindle is fully supported at the top and bottom, just like the factory design. I'll post up a link to his build when I can find it again. Edit: Took some searching but I finally found the link: http://the510realm.com/viewtopic.php?p=55643#p55643 Note: Edited as I forgot to include the wording about the bushing in the Timing Cover. I assumed every one knew that existed. And the bushing in the TC is not adequate to prevent spindle shaft whipping or " whirling ". See post #7 below with engineering link.
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