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  • #31
    Originally posted by andywander View Post

    Harley V-Twins up until the early 1960s used the "wasted spark" system, for points and battery ignition as well. And they don't have a distributor, just a thing that looks like one, with the points in it, but no plug wire connections.
    If it's a Harley the spark is always wasted no matter what system it's running ...

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    • #32
      Originally posted by A.K. Boomer View Post

      If it's a Harley the spark is always wasted no matter what system it's running ...
      Clever! But, I'm pretty partial to my 1952 FL...

      Comment


      • #33
        As for polarity etc, it matters as to what system is used. Regular traditional ignition works like a flyback SMPS..... energy is first stored in the coil inductance, when the points or the transistor switch close, and is then released into the spark plug when the points or switch open. Yes, the initial pulse has a given polarity, but there are a number of oscillations, many of which also produce sparks. So there are also some opposite polarity sparks.

        Some modern systems work like a "forward" converter type SMPS, where there is no storage, and the first pulse (closing of circuit from + to -) produces the spark, instead of just storing the energy. there may be oscillations, but the first pulse is very much the strongest pulse.

        Systems with a very strong initial pulse (capacitor discharge systems are typical) will produce a more obvious difference in wear than the traditional ignition system.
        2730

        Keep eye on ball.
        Hashim Khan

        Everything not impossible is compulsory

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        • #34
          My BMW bike has two plugs per head. One plug in each cylider head is fired by stick coil so not wasted spark. The second plug in each head is fired by a conventional coil with long plug leads firing both cylinders on a wasted-spark basis so the second plug is doing double-duty however the service shedule calls for all plugs to be changed at the same service interval.

          So the wasted-spark system may well wear the plugs out quicker but BMW at least didn't appear to consider it an issue in this system.
          Last edited by Peter.; 07-24-2021, 02:39 AM.
          Peter - novice home machinist, modern motorcycle enthusiast.

          Denford Viceroy 280 Synchro (11 x 24)
          Herbert 0V adapted to R8 by 'Sir John'.
          Monarch 10EE 1942

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          • #35
            Originally posted by I make chips View Post
            ................ spark plugs.
            At 101,000 miles they looked new and with a little anti seize they went back in. I'll probably lose the set of new ones I have before they are needed.
            Just an FYI for everyone, spark plugs are better than they used to be and ALL spark plugs makers recommend that anti-seize NOT be used any more.

            https://ngksparkplugs.com/en/resourc...ut-spark-plugs

            Steve

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            • #36
              Originally posted by SteveF View Post

              Just an FYI for everyone, spark plugs are better than they used to be and ALL spark plugs makers recommend that anti-seize NOT be used any more.

              https://ngksparkplugs.com/en/resourc...ut-spark-plugs

              Steve
              Yup

              Those NGK engineers have never had to remove the plugs from 250K engines. I have, busted off at the hex. Drilled the base out to the thread coil. Peeled the thread coil out with a needle nose plier. Sucked the debris out with the shop vac and careful control of the piston /valve position. It was a cheap car so not a lot to loose.

              Yup it was an NGK plug (my favorite}

              But a small dab of never-seeze goes on every plug I install!.

              Comment


              • #37
                Originally posted by Edwin Dirnbeck View Post
                Some gm cars have 2 spark plugs firing at the same time from i coil. One plug is on the compression stroke and the other is on the exhaust stroke. The plug firing on the exhaust stroke does nothing ,hence it is wasted. My question is, why would the electricity choose to jump gap on the plug that is under compression. I allways thought that the higher the pressure ,the harder it is for a spark to jump. I seems that the electric would take the eazy way out and jump the plug that is on the exhaust stroke..Edwin Dirnbeck
                Hey Edwin. For starters I didnt read any other replies right, just talking with you.. (Side note I had a Great Uncle Edwin).

                The two spark plug thing for spark timing is new to me.

                I know internal combusion engines have used dual plugs in one combustion chamber for good reason for years now. But always firing at the same time.

                The "re-fire" of the exhaust gas was their attempt to limit the raw hydrocarbons to escape through the tail pipe. They said lets burn them first, it wont produce any energy but it might make our Carbon footprint smaller.

                Sort of like that right? Yeah...

                I have more faith in our Engineers, even thogh I talk chit about them (I had to work with them ) to know they had the best intentionions across the board. So it was a flawed system.

                What I do in that situation is rip out the flaw, could be an air pipe that feeds from the exhaust to the intake (air pump) or a screwy engine with too many spark plugs.

                Remove the problem. Problem solved. JR

                Oh thats right?

                Originally posted by Edwin Dirnbeck View Post
                My question is, why would the electricity choose to jump gap on the plug that is under compression. I allways thought that the higher the pressure ,the harder it is for a spark to jump. I seems that the electric would take the eazy way out and jump the plug that is on the exhaust stroke..Edwin Dirnbeck
                Oh, thats right, the question at hand..

                An old wives tale as it were.. The electrical voltage gap doesnt see any difference if the pressure is 120psi or 25,00psi.

                Its the "junk" inbetween the voltage gap that changes. Thats why vacuum tubes.

                So in the internal combustion engine the key is to stuff as much fuel and oxygen (air in this case) into it.

                When doing so with some combustion chambers benifit by having two sprak plugs and then the giant Wash of air and fuel doesnt put the flame out.

                Dual plugs are all about not washing out the frontal flame. Or flame front JR




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                • #38
                  While we are at it

                  My '79 RX-7 rotary engine has two plugs per combustion chamber.

                  Two coils and a duplex set of points in the distributor. The plugs fire sequentially. I guess the rotor sweeps past the one and needs the other to finish the job of burning the fuel charge.

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                  • #39
                    On wasted spark systems the coil is not grounded so, the spark must jump on both plugs making the ground connection between them the return path. CDI ignitions will create the same polarity always so, one plug will always be positive and the other negative. There would be no harm in exchanging the pair's wire connection at regular intervals to even the wear.
                    Helder Ferreira
                    Setubal, Portugal

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                    • #40
                      Originally posted by CalM View Post
                      While we are at it

                      My '79 RX-7 rotary engine has two plugs per combustion chamber.

                      Two coils and a duplex set of points in the distributor. The plugs fire sequentially. I guess the rotor sweeps past the one and needs the other to finish the job of burning the fuel charge.

                      Hahaaa, you know like the rx-7s

                      They eat oil like its fuel FYI... Thats why they never took off... JR

                      Comment


                      • #41
                        Originally posted by JRouche View Post

                        Hey Edwin. For starters I didnt read any other replies right, just talking with you.. (Side note I had a Great Uncle Edwin).

                        ..

                        I have more faith in our Engineers, even thogh I talk chit about them (I had to work with them ) to know they had the best intentionions across the board. So it was a flawed system.

                        the frontal flame. Or flame front JR



                        Right now, I have zero faith in polaris engineers.. I have an expensive 2005 polaris 700 with electronic fuel injection. It has been garage kept and only has 100 hours. It misses and sputters.It has bosch feul injection with proprietary diagnosis connecters WITH ENCRYPERS. The local dealer wont work on anything older than 15 years. The only way to fix it is with STUPIOD POLARIS DEALER ONLY DIGITATAL WRENCH.Soooooo I am getting all the learning that I can on all the systems,so that I CAN FIX IT MYSELF. .NEVER BUY POLARIS. It is companies like POLARIS that encourage people to want more laws . I dont like more laws. More and more products are ending up in the land fills because of greedy corporations. Edwin Dirnbeck

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                        • #42
                          Originally posted by Noitoen View Post
                          On wasted spark systems the coil is not grounded so, the spark must jump on both plugs making the ground connection between them the return path. CDI ignitions will create the same polarity always so, one plug will always be positive and the other negative. There would be no harm in exchanging the pair's wire connection at regular intervals to even the wear.
                          Hey that's an honorable mention, lets say someone just wanted to run less expensive single platinum's and get the most out of them... if their cake to swap out like in a simple easy access in-line 4 banger then that would be the ticket as the wires may not always reach ----- also possible to just rotate the coil 180 degree's like with a subie, then plug the leads back in, if it mounts back up and the power leads still reach why not...

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                          • #43
                            Originally posted by Edwin Dirnbeck View Post
                            Right now, I have zero faith in polaris engineers.. I have an expensive 2005 polaris 700 with electronic fuel injection. It has been garage kept and only has 100 hours. It misses and sputters.It has bosch feul injection with proprietary diagnosis connecters WITH ENCRYPERS. The local dealer wont work on anything older than 15 years. The only way to fix it is with STUPIOD POLARIS DEALER ONLY DIGITATAL WRENCH.Soooooo I am getting all the learning that I can on all the systems,so that I CAN FIX IT MYSELF. .NEVER BUY POLARIS. It is companies like POLARIS that encourage people to want more laws . I dont like more laws. More and more products are ending up in the land fills because of greedy corporations. Edwin Dirnbeck
                            It all started with crimped together, non-serviceable fuel pumps.
                            No diaphragm able to be replaced, just buy a new one.
                            (maybe not, I just made this up, but you get the idea.)
                            But I just hate things designed to not be able to fix.
                            Like aluminum radiators. Copper / brass radiators can be soldered.
                            Aluminum / plastic radiators are a lost cause. Maybe JB Weld as a temporary fix, but sketchy at best.
                            That is why I have 3 International trucks from the 1950's. No plastic. All fixable. Very satisfying to
                            work on, a pleasure to own and drive. I am rebuilding and swapping out the engine in one right now.
                            Replacing an 80,000 mile, worn out 220 Cu In engine with a 20,000 mile 264 Cu In engine.
                            Will be going from 90hp to 150 hp. It will be like going from a Cadillac to a Corvette for me ! ! !
                            I might be able to actually do the speed limit now. Ha ! ! ! Loving it all the way.
                            I might even change the 3 speed to a 4 speed and really live on the edge.
                            I already have a new rear end lined up. Going to change from the 4:1 ratio to a 3:1 ratio and get some
                            more speed, or at least less revs. Might make the granny gear on the 4 speed more usable too.
                            No computer. No wondering what is wrong when something breaks. No tire pressure sensors.
                            No power windows. No filling up with premium gas. Just basic mechanical fun.
                            Oh, spark. Just points and condenser and a basic dizzy. Oh, I added a ballast resistor because I made
                            it 12 volts. I added a 1 wire GM alternator (more simple than the genny rig) and I use a small 12v
                            battery and thin 8ga battery cables, just to keep from hurting the starter Bendix. I think I added halogen
                            headlights, so I can see now. All easy to work on. Love it. New pickup trucks are pure trash.
                            Remove the cab to work on the emission controls. Keep it.

                            --Doozer
                            DZER

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                            • #44
                              That is why I still have my AMC Jeep sitting in the driveway. The only plastic unrepairable is the dash pad and the steering wheel. And those can easily be swapped for older CJ3 models. Imagine a lawn tractor with a tent on top, that's what driving it is like.

                              Bummer about the aluminum radiator and heater core tho. Acquaintances who retired from Harrison Radiator tell me the whole reason for that is because moar profit margin. The copper replacements are now around $500 ea. Alu is way way cheaper and the makers get to pocket more $$$ for the stock market. Notice that being cheap bastards didn't stop GM from going BK.


                              Originally posted by Doozer View Post

                              That is why I have 3 International trucks from the 1950's. No plastic. All fixable. Very satisfying to
                              work on, a pleasure to own and drive.
                              .....
                              ...All easy to work on. Love it. New pickup trucks are pure trash.
                              Remove the cab to work on the emission controls. Keep it.

                              --Doozer
                              25 miles north of Buffalo NY, USA

                              Comment


                              • #45
                                Speaking of being able to fix or repair things on new cars, or more correctly not being able to fix them, here's short little video that is a reminder of what the cost can be.
                                This one although aimed at GM can also be directed at just about any new car manufacturer, so certainly not a cheap shot at GM alone.
                                Saw this one from a YT channel that I watch occasionally produced by a small mom & pop automotive repair shop in upstate New York, South Main Auto Repair.

                                GM's joke of the day;

                                Home, down in the valley behind the Red Angus
                                Bad Decisions Make Good Stories​

                                Location: British Columbia

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