HF79 gas/elect. converted to straight gas power

Discussion in 'Frame Mounted Engines' started by professor, Jul 24, 2010.

  1. professor

    professor Active Member

    Being that it is now a NY legal moped, I decided to make the bike more efficient and a little lighter.

    Deleted- 450w motor and one battery, Ford alternator, controller.

    Added- 250w motor acting as a generator, another jackshaft, belts, clutch idler.

    My plan was to use a delco (internal regulated) alternator to supply the juice for the mandatory head/ tail/ stop lights. Boy, did that not work. The Delco sucked a huge amount of power from the HF.
    Decided to put a 250w scooter motor right where the Delco was and use it for juice by spinning it like I did the Delco. Driving it just a tad slower than the HF.
    I used a diode from an old generator to prevent juice from motoring the motor during off or low rpm situations. ( important)
    If you do anthing like this- also make sure all your polarities are right- spin the "generator" one way and you get different polarity than the other way from the 2 leads out of the "generator".
    I guess if the battery was deleted, this would not matter, but I wanted to battery to give power at engine /off plus it acts as a bank to stuff excess juice (for a bit) into, so lights won't over volt.

    Cranked up the engine with the lights on and =12.55 volts- rev the engine real good ,and voltage goes to 13 something. Yeah- that will work.

    Gear ratio- guessed at 15 to one and it was too low. launched like a rocket, made a lot of noise, (big amount of engine clatter, real quiet exhaust and intake) the HF clatters like an old motorcycle (did you know it is a Hemi).
    So I changed the pulleys and could hardly get going- but would idle at 20 mph or so- the odd thing is, that once rolling, even with what seemed like 3rd gear- it would pull strong.
    OK, change the gearing again (to another unknown number (didn't count) and it feels like 2nd gear in my Toyota. Comfortable cruising speed around 20. A little clutch slip required to get moving. I can't imagine a hill that would slow this thing down.

    A note on chains- I tried a bike chain as an intermediate power thansfer and it was incredibly LOUD - went back to the little #25 scooter chain and -quiet as a mouse. Amazing.

    I am going belt to the first jackshaft, them #25 chain to the second jackshaft (actually a modded scooter rear axle with a freewheel).

    A note on using belts with idler/clutchs- with the belt in the "not engaged" mode- it helps to have little "Guides" that keep the belt near- but not riding(as much as you can) on the pulley sheaves. Belts naturally "Want" to go to a roundish shape which puts drag on the sheaves.
    These little stops keep them from doing that.
    Sometimes it is necessary to make one to hold the belt from spinning (have a little tractor that I could not get into gear until I made one for the idler arm).

    Why not just use one jackshaft?
    Because I already had another one, and using 2 of them gets away from needing a huge pulley (as on the the single set-up).

    I took the pics without the shopping bags that normally adorn the sides so you could see the works underneath.

    Using a dual brake handle on the right hand -takes serious effort, but stops OK.

    Using a HT clutch handle on the left hand - only backward action- squeezing makes you go and locking it keeps it engaged.

    Yet to do- make chain guards. Make a wiring diagram so I will be able to figure out this thing later.

    What I would like - add a derailer on the engine side with a smaller sprocket that would give an even more relaxed cruise rpm.
    Probably won't do it. I don't go fast and it would be yet another control to work.

    Here are pics:

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