Magneto update

Discussion in '2-Stroke Engines' started by Fabian, Apr 7, 2014.

  1. Fabian

    Fabian Well-Known Member

    My engine supplier has just got his hands on a 66cc sample engine for me to test; using the new magneto design.
    If i find that it's reliable and operates with similar efficiency as the current magneto/coil design, he will order a container shipment.

    The engine is similar if not identical to a Grubee Skyhawk "SuperRat", in that it uses an identical 47mm bore, though the stroke is 38mm instead of the "SuperRat" 40mm stroke, which makes the "Rat" engine 69cc; an extra 3cc over the engine i have received.

    Here is the engine on the Grubee webpage: http://www.grubeeinc.com/USA/SkyHawk%20Gt5-SR%20SuperRat.html

    Having said that, the normal 70cc engines he sells use a 40mm stroke, so if the crankshafts are the same between the new engine design and the old engine design, it would seen logical that the longer stroke crankshaft could be retrofitted into the new engine design.

    Thankfully this new engine design is now being sold in the mass market; making magneto parts readily available; Gasbike being one of the suppliers: http://www.gasbike.net/grubee-skyhawk-gt5-sr-66cc-80cc-slant-head-standard-finish-bike-motor-kit.html



    The next question directed at my bicycle engine kit supplier was of the ignition advance curve: was it a 4-stroke advance curve like the commonly available magneto/CDI or a proper 2-stroke ignition advance curve.
    It turned out that he was unable to give me an answer so i had to do some more digging, hence i went to town on Google.

    Doing some research revealed that this particular integrated magneto system is used on the 2-stroke 3WF18 misting blower,

    http://www.delshine-garden.com/pid12366891/3WF18-9+(20L)+131kw+Agricultural+Power+Sprayer.htm

    http://www.alibaba.com/product-detail/coil-and-rotor-for-WFB-18_307572702.html


    and


    the company that manufacturers the integrated magneto is Zhongci, which lists the part number as ZC6002, so spare parts supply is not a problem,

    http://www.cnzhongci.com/ENGLISH/productshow.asp?id=1198




    so, without further ado, here are the photos,


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    A side note is that a small flywheel puller will be needed to remove this type of magnet from the crankshaft:
    $_12.JPG





    [​IMG]
     
    Last edited: Apr 7, 2014

  2. velzie

    velzie Member

    But how do you replace it with Jag's CDI?
     
  3. Fabian

    Fabian Well-Known Member

    With the altered design, you no longer need a Jaguar CDI; if compression ratio is kept within reasonable limits, considering the circuit design should be optimised for 2-stroke operation; as it's used in a 2-stroke misting-blower.
    If it really does use an ignition curve properly optimised for 2-stroke operation is another discussion in itself, and will require testing by someone who has the skills and equipment to create a graph of the ignition curve.

    The benefit of the Jaguar CDI is that of ignition curve adjustability, with the V2.0 adding an automatic correction parameter for ambient air temperature variation.

    The integrated magneto/CDI/coil system will not operate a Jaguar CDI, unless a specific magneto coil is designed for the new circular magnet.


    A significant benefit of the new design is simplification of the wiring system, by use of an all-in-one magneto/CDI/coil which is typical of the ignition systems found in chainsaws.
    Another benefit is that of trouble shooting an intermittent ignition problem, because if you suspect an ignition problem, it's so much easier (after you've replaced the spark plug) to throw the integrated magneto/CDI/coil/spark plug lead over your shoulder and (by only unscrewing two screws) replace it with one single item.

    This has many positives in that only a single electrical spare part is needed in your bicycle tool box, when touring on the road, and it requires no more than 60 seconds to replace the entire electrical system; which also reduces clutter as no electrical parts are attached to the bicycle frame.
     
    Last edited: Apr 7, 2014
  4. velzie

    velzie Member

    I am interested to see what it's timing curve looks like, and its quality of spark. Hopefully the misting blower isn't timed like our engines but more like proper 2-strokes that use this design. I am not a fan of packaging separate units into one larger, combined unit. Might make replacement more expensive. Also, if the unit isn't timed well, or if you would like something more adjustable, it might make an improved unit more expensive.
     
    Last edited: Apr 7, 2014
  5. Fabian

    Fabian Well-Known Member

    Ironically it could make the product cheaper considering the coil and magneto coil and the ignition coil are all contained in one "sealed" unit. Typically, sealed units seem to be more resistant to vibration and moisture ingress.
    My experience with Chinese bicycle engines and their associated electronics, in comparison to the electrical reliability of chainsaw style ignitions has proven integrated systems to be exceptionally reliable.

    If the ignition curve on the new integrated magneto/CDI/coil/spark plug lead proves to be suitable for conventional operation with an after market medium compression billet cylinder head, then it's goodbye to the Jaguar CDI, which was only needed because the standard CDI used a 4-stroke ignition curve; hammering out the big end connecting rod bearing.

    If you want something adjustable, then you always have the option of purchasing an engine using the current ignition system layout, thereby allowing use of the Jaguar CDI.
    It so happens that my bike has always been fitted with a Jaguar CDI and coil (after my string of engine failures using a standard CDI) and has served me well over time; with equal electrical reliability as compared to the standard CDI/coil combo, but giving "all" of my engines a dramatic improvement in connecting rod bearing life; massively increasing engine reliability.

    however,

    if the new integrated ignition proves to be reliable and proves to be just as kind on the connecting rod bearings, the new magneto system will become my preferred ignition system.

    Time will tell, but unfortunately i won't be installing the engine until my current engine starts to give up the ghost, which ironically i am hoping for (because it uses the old style caged needle roller big end connecting rod bearing), but the way the engine is running, it's not going to happen any time soon.
     
    Last edited: Apr 7, 2014
  6. jaguar

    jaguar Well-Known Member

    I think it is an improved version of the old CDI/coil but with the same ignition curve which means you are asking for trouble if you increase the compression or increase the peak RPM. Blowers probably don't rev higher than 5K anyway.
    If I were you Fabian I would swap engines just out of curiosity if nothing more.
     
  7. velzie

    velzie Member

    For the greater good!
     
  8. Fabian

    Fabian Well-Known Member

    Don't you all worry your little beating hearts because "i will" be changing my current engine (when it eventually fails) to the new engine with updated magneto design, upon which "i will" then beat it to death; seeing how it holds up under the torturous conditions experienced on my touring journeys.
     
  9. luciusbubblepot

    luciusbubblepot New Member

    Out of curiosity has any one tried like say a chainsaw flywheel magneto combo on one of these motors
     
  10. Fabian

    Fabian Well-Known Member

    That's an assumption.
    Have you graphed this ignition system to verify that your assumption is correct?
     
  11. HeadSmess

    HeadSmess Well-Known Member

    you change the initial advance/retard point by filing the mounting holes. simple.

    you change the degree of advance by filing the stator arms at an angle or notching them. simple.


    hammers out YOUR conrod bearings.... mine seem to hold up fine at 7000rpm + with standard CDI unit...

    at least someone has the capital to invest in some new tooling.maybe some engineer in china just realised that google has a translate function and has started reading?


    i dislike the inability to be retrofitted, or maybe they can be?



    yes, assuming makes an ass out of you and me...so who will be first out with the timing light and a permanent marker? the answer to how the curve progresses will become apparent in the first five seconds...but then, cant rev it past 5000 rpm now, can we? it might explode... better be careful and put a rev limiter on it, just in case.


    more to the point...give us a picture up the exhaust port at BDC.... until that issue is fixed, all "70cc" engines are :9898:
     
  12. jaguar

    jaguar Well-Known Member

    the chinese make the timing curve to match the engine. In this case a low peak RPM engine with low compression and poor fuel atomization.
    If you improve the compression, increase the RPM by porting, or put a good carburetor on then that calls for more spark retard at high RPM like what my CDI provides. Unfortunately it doesn't look like there's any easy way for me to make my CDI work with it on a mass produced basis. If I owned one I would gut the electronics, leave only the stator coil, and connect it to my CDI which then connects to a high voltage coil. But gutting things encased in epoxy is very hard and often results in a damaged stator coil.
     
  13. FordRanchero289

    FordRanchero289 New Member

    On a side note... Is the wire removable from the cdi housing or is it permanent? I just bought an engine with this setup and I'm hoping I can replace the wire. Its a dragon fire flying horse motor in black.
     
  14. skyash

    skyash Active Member

    Specs on it say 500 to 8500 rpm. trying to get one to put on my bike if it's better??
     
  15. jaguar

    jaguar Well-Known Member

    Fabian I'd like you to do a test with it to give us an idea of how much voltage it can send to the spark plug.
    Test for spark outside the engine with the plug grounded to the engine.
    Keep increasing the spark gap till it will no longer spark the gap.
    then tell me what was the maximum gap it sparked and I will use a formula to figure out what voltage that translates to.
     
  16. HeadSmess

    HeadSmess Well-Known Member

    or get an electric fence tester and save your coil insulation ;)

    where is fabio?
     
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