Distributor Rotor Phasing 101

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  • Опубликовано: 15 дек 2024

Комментарии • 12

  • @SuperDirtyred1
    @SuperDirtyred1 Год назад

    Hello, I am doing a HEI install on a AMC 360 , What I need to know is, do I keep or take off the the voltage regulator ? Thanks for the Video's.

    • @SnowFamilyRacing
      @SnowFamilyRacing  Год назад +1

      The voltage regulator is on the charging system. Do you mean ballast resistor? Yes, the HEI needs 12 volts to run properly. If there's a ballast resistor, it needs to be bypassed.

    • @SuperDirtyred1
      @SuperDirtyred1 Год назад

      Thanks , Have a great day.@@SnowFamilyRacing

  • @jaygooch1190
    @jaygooch1190 Год назад

    Your supposed to check the timing with the vacuum advance disconnected. You shouldn't have vacuum on the vacuum advance pod at idle anyway

    • @SnowFamilyRacing
      @SnowFamilyRacing  Год назад +1

      If you were watching, we were manipulating the vacuum advance with a vacuum hand pump to move the rotor to be more in line, or in phase, with the distributor terminal. As we moved the position of the rotor in relation to the terminal, we also moved the distributor accordingly to keep the desired timing. This is called rotor phasing. The vacuum advance mechanism was welded so that it wouldn't ever move and essentially hold things exactly where we wanted them. The intent is to not have the spark energy jump any more gap than is absolutely necessary so that the energy gets to the spark plug and isn't wasted along the way. If you watched thinking we were setting the timing, watch again with an eye towards phasing, and it'll make more sense. Believe it or not, I watched my guest do this on several cars, and they all performed better on the track.

  • @thomasdemarco617
    @thomasdemarco617 3 месяца назад

    the reluctor and the picup points need to be aligned

  • @BigDaddyThrock
    @BigDaddyThrock 2 года назад

    Quick question, I have a 85 Camaro hei with no mechanical or vacuum advance. I’m converting it to a Msd fired setup with efi controlled timing. Originally the distributor was controlled by the car’s factory computer. Is phasing possible or even necessary?

    • @SnowFamilyRacing
      @SnowFamilyRacing  2 года назад +1

      Msd does sell phasing rotors that can be used with specific distributors. Make sure you use a distributor that is compatible with your whole ignition and injection system.

  • @keiths9483
    @keiths9483 3 месяца назад

    Of course, you could always get an adjustable rotor....

    • @SnowFamilyRacing
      @SnowFamilyRacing  3 месяца назад +1

      A quick search shows that the adjustable rotors are available for the small cap stuff,and I didn't actually see an adjustable rotor for a large cap HEI.

  • @BruceCoggins
    @BruceCoggins 3 года назад +2

    Warning...HUGE wall of text 😉
    A few things I want to talk about that maybe weren’t clear on the video…This distributor was already locked out. Also, It’s hard to see but when checking the rotor phasing on this distributor, the rotor was firing at the trailing edge of the terminal. This is just fine, and we could have just left it as is but I wanted to show how easy it is to adjust Rotor Phasing on an HEI distributor.
    Over the years, I’ve read on many automotive tech forums that HEI’s can’t be phased or that you need to have some special “adjustable rotor”. Well, that’s not true. HEI’s are actually quite easy to phase.
    There is one important point I want to make though and that is when phasing an HEI with a module in place, the timing will retard as the RPM increases. Here’s why…All HEI modules have a certain amount of dwell built into them. Stock HEI distributors have weights and springs that work with centrifugal force and will advance the timing to counteract the lag in dwell time. When you remove the weights and springs and weld or lock the shaft to the top plate, there will be no movement to adjust for the dwell that is built into the module. That dwell time doesn’t change so as the RPM increases, the timing will naturally retard. So, the point I want to make clear is if you decide to lock out your HEI you must remove the module so, that means you need an ignition system to fire the magnetic pickup. With a good ignition system and a locked out HEI without a module, the timing will remain stable in all RPM ranges.
    Back to rotor phasing…First, remove the springs and weights. It really doesn’t matter where the top plate is in relation to the shaft but typically most people move it to the full advanced position and then weld it. You can also predrill a couple of holes and use screws to lock it into position. Next, you can either go ahead and weld the rod on the vacuum canister now or keep it functional temporarily to make phasing the rotor a little easier. You can still make the phasing adjustment even if the rod is already welded so I’ll go over that in a minute.
    With the distributor welded and the vacuum canister still functional and installed, it’s time to reinstall the distributor in the engine. You will need to rotate the engine to the desired total timing number that you want. Let’s say you want the total timing set at 35 degrees…turn the engine over until the timing pointer is on 35 degrees before top dead center. Place a mark on the distributor housing indicating the number one terminal and drop the distributor in. Obviously, you will need to turn the rotor counterclockwise a little bit so as you drop in the distributor, the rotor will rotate clockwise as the teeth line up. If it doesn’t drop all the way down, then either remove the distributor and adjust the oil pump shaft or just bump the engine a couple of times and it will drop down.
    You will need an old distributor cap so you can cut a hole into it for this next part. Cut a hole directly under one of the posts…doesn’t matter which one so just choose the one that is easiest to see. Next, hook your timing light up to that cylinder/sparkplug wire where you cut the hole. Two timing lights make adjusting this much easier, but you can do it with one. If you have a second timing light…assuming you cut the hole out on any other post besides number one, then hook that light up to the number one sparkplug wire so you can read the timing. Once the distributor is in, verify the rotor is lined up with the number one terminal and install the cap and wires and start the engine. Keep in mind, at this point you will be running full advance so if it’s too far advanced the engine will have a hard time starting. I very highly recommend using a start retard of some kind.
    With the engine running, first, verify the timing and adjust it as necessary. Now using the timing light on the sparkplug wire where the hole is cut out, check the rotor phasing. If it’s firing on the trailing side of the terminal then using a vacuum pump on the vacuum canister, slowly apply vacuum and you’ll see the rotor move counterclockwise or towards the middle of the terminal. When this happens, the total timing will also change (it will advance in this case) so you will need to go back and reset the timing. You’ll probably need to go back and forth a few times to get everything set up how you want it. Once it is set to where you want it, take note of the amount of vacuum applied to the canister or else lock the rod in place somehow. You will need to remove the canister and throw a quick weld on it, so the rod needs to be in the correct location. You can even mark the location with a marker for reference.
    If the rotor is firing at the leading edge of the terminal, then you will need to move the magnetic pickup back or in. You will need to elongate the mounting holes on the vacuum canister to give you enough adjustment to correct the phasing. If you have already welded the rod to the vacuum canister then you will need to elongate the holes so that you will be able to move it either in or out to make the adjustment. I recommend, if it is already welded, put it in and see which direction it will need to go and then elongate the holes in the proper direction. Once again, as you make adjustments to the magnetic pickup, you will need to go back and readjust the timing. I prefer to have the rotor firing just before the middle of the terminal in order to give the maximum area for spark to occur.
    Once this process is complete, you may need to pull the distributor and move it clockwise or counterclockwise one or two teeth to make the distributor sit “square” or you can just leave it.

    • @SnowFamilyRacing
      @SnowFamilyRacing  3 года назад

      That was one of the most informative walls of text ever written! Thanks for that!