Diesel?

Discussion in 'Motorized Bicycle General Discussion' started by RecycleBill, Nov 8, 2009.

  1. RecycleBill

    RecycleBill New Member

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    I've never been a fan of 2 cycle engines but in years gone by I drove a million miles or more behind the wheels of several 2 cycle diesel trucks of the 6-71 and 8-71 Detroit Diesel variety. And when I was a kid my grandfather had an International engine that cranked on gasoline then was switched over to diesel after it was warmed up. It was used to run his sawmill.

    Has anyone ever tried to convert one of these chinese 2 strokes from gas to diesel? I'm sure a glow plug would be required along with some changes in the way the air/fuel mix is delivered to the cylnder but it seems it might could be made to work.
     
  2. 2door

    2door Moderator
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    Bill,
    I'm sure you remember diesel model airplane motors. They were strong runners but a little temperamental when it came to cold starts. My dad and I had a couple of them and he used to warm them with his cigarette lighter on cold days before flipping the prop. It would be an interesting project not to mention the smell from the exhaust. There has been some discussion here but to my knowledge no one has done a successful conversion. Keep us informed if you try it.
    Tom
     
  3. robin

    robin Member

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    Do they require a high rate of compression like 15 to 1 ? in order to get heat ? if so can the Chinese engine deliver it ?
     
  4. 2door

    2door Moderator
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    You'll just need a bigger cigarette lighter. :)
    Tom
     
  5. GearNut

    GearNut Active Member

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    *carries MAPP gas torch in back pocket*
     
  6. RecycleBill

    RecycleBill New Member

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    A cold diesel does require very high compression rates and without a doubt the Chinese engine would burst apart if you raised the compression that high. But a hot diesel engine will run on very low compression rates-- as low as gas engines. That's why a good glow plug like those used on Ford 7.3 liter diesels (Think F-450) or MB diesel cars would be needed.

    If one can manage the correct air/fuel ratio then smell and smoke won't be a big issue. And if it will run on regular diesel then it will run on bio diesel and will smell like french fries.

    Might be just the thing for someone wanting to motorize his or her bicycle catering cart.
     
  7. TheOtherStyle

    TheOtherStyle New Member

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    Well they do already have small 1cyl diesels, I'm sure it wouldn't be hard to adapt one to a bicycle in one form or another.

    I saw a motorcycle in one of the bike magazines that was hydraulically driven by a small diesel. I can't find the link right now or I'd share it with you guys.

    However check this out DieselBike.net The Original Diesel Motorcycle website.
     
  8. Kevlarr

    Kevlarr New Member

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    Like 2-door said this was discussed before and the consensus was that either you would have to run them on model airplane "diesel" fuel which isn't (it's mainly lamp fuel, castor oil, ether and expensive to make and even more so to buy, like $30 a gallon) because the motor couldn't handle the compression needed to run on actual diesel, bio or otherwise.
     
  9. RecycleBill

    RecycleBill New Member

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    Does anyone know the actual compression ratio of the Chinese 2 strokes? I ask this because I've seen other gasoline engines with around 8-1 compression ratios operate on diesel. Take any old carbed car engine, get it hot, close off the gas line and start pouring diesel in it and it will run. Not well, but it will run.

    Again, the trick is not in running the engine but in getting it to start. Which can be done with glow plugs.

    And would diesel fuel or bio diesel provide adequate lubrication?
     
  10. bandito

    bandito New Member

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    Google alibabba diesel one cylinder engines........I made an ass out of myself with grandiose plans not knowig the intricacies of importation and customs into the USA.....the single deisel single cylinder engines you seek are there.
     
  11. RecycleBill

    RecycleBill New Member

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    So much for compression being a problem. From the Practica Foundation Micro Diesel Project: Micro diesel engine | Practica Foundation

    Specifications
    Displacement 18 cm3
    Power output 0,6hp at 6000rpm
    Cycle two stroke
    Compression Variable between 0 and 1:50
    Fuel Kerosene, diesel or vegetable oils
    Weight of bare engine (approx) 15kg
    Cooling Water cooled, air-cooling optional
    Speed control Internal governor
    Power take-off shaft 1500rpm, 1:4 ratio to crankshaft
    Starting Crank
    Power take-off (2, start shaft) 365 rpm
    Specific fuel consumption 300-400gr/hp.h
    Fuel cons. at 0,2hp/5700rpm 0.15 l/h

    Of course, this engine is too small and can't be bought. And all the available diesels I've found are 250cc or larger-- too big to be legal on a motorized bicycle. And they're all too heavy.


    Anybody know which is the better of the 50cc Chinese 2 stroke kits? I'm thinking I might want to tinker...
     

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