very small high horsepower airplane engine

Discussion in 'Friction Drive' started by ratdoggg, Jan 14, 2011.

  1. ratdoggg

    ratdoggg Member

    I have been looking at some of these small engines they use on
    r/c airplanes.. Some of these have very high horse power for a very small engine.
    Question is this: These engines are made to use a prop and do not have a flywheel.
    Would they work with a friction drive bicycle. One day I think it would (using the bike
    wheel as the flywheel) then the next I think it would not any body have any experience
    with something like this???:jester:

  2. DuctTapedGoat

    DuctTapedGoat Member

    Well, I'll say this.

    I'm looking at 2stroke <1cc vintage plane motors to do a motorized flip trick bike (finger bike).
  3. Wheres my dog

    Wheres my dog Banned

    Ratdoggg... indeed very high horsepower BUT what is needed to turn that bicycle wheel is horsepower along with torque!

    If you think about the propeller spinning there is very very little resistance against it turning hence the low torque range.

    From all I have read and seen, they are not a worthy candidate for a friction drive
  4. Skyliner70cc

    Skyliner70cc Active Member

    Depends on the size engine you plan to use. Torque is what spins a prop and there is mucho resistance that a prop experience. The resistance is proportional to the size of the prop the engine can pull.

    This RC engine would be a sweet ride but factors such as cooling may be an issue since larger cooling fans would be needed for a bike application.

    Displacement: 12.20 ci (200 cc)
    Output: 19 hp
    Weight: 10.95 lbs (4.95 kilos)
    Bore: 1.6771 in (42.6 mm)
    Stroke: 1.3779 in (35 mm)
    Length: 9.625 in (244 mm)
    RPM Range: 900 - 6,700
    RPM Max: 8,500
    Fuel Consumption: 4.5 oz/min @ 6,000 RPM
    Warranty: Two years

    Four petal reed valve, bottom induction.
    Desert Aircraft, auto advance, electronic ignition.
    Walbro Carburator
    Exclusive Desert Aircraft designed cylinders, pistons, and crankshaft.
    CNC milled, 7075 aluminum alloy crankcase.
    Low vibration.
    Long rod to stroke ratio.
    Aerobatic power curve.
  5. Skyliner70cc

    Skyliner70cc Active Member

    This small 400cc radial radio control model airplane engine is pretty sweet but I'm sure it desn't have enough torque to pull a string out of a puppies but ;-)

    It could easily fly a model airplane in excess of 100 lbs.

    Now, if the OP was talking about smaller engines, i agree a .40 cubic engine (1.2 hp) ENGINE ISN'T GOING TO CUT IT FOR A BIKE. That engine produces that 1.2hp at 17000 rpm and you will need a reduction to convert that to a useable operation (not practical).
  6. Skyliner70cc

    Skyliner70cc Active Member

    This engine would be a favorite of mine.
    JetCat SPT5H Engine complete with starter.
    Power: 11.2Hp
    Weight: 4.9 LB, incl. starter
    Length: 15.25 inches
    Turbine RPM Range: 50,000 - 165,000
    Gearbox RPM Range: 1500 - 7000 RPM
    Exhaust gas temp.: 580°C -710°C
    Fuel consumption: 8 oz per/min at full power
    Fuel: Jet A1, 1-K kerosene
    Lubrication: approximately 5% synthetic turbine oil in the fuel
    Maintenance interval: 25 hours
    Last edited by a moderator: Dec 18, 2015
  7. ratdoggg

    ratdoggg Member

    The reason that I got interested is that I found out that weed wacker conversions are popular
    conversions for large r/c air craft and boats.. Sooooo it would follow that the opposite would be
    true and the like 50cc 3 and 4 or five horsepower r/c 50cc motors would be killer on a bike if one
    wanted to step up and pay the price of admission..and yes a plane requires a lot of torque to turn a
  8. DuctTapedGoat

    DuctTapedGoat Member

    How much is a weed eater at a thrift shop?

    How much is an R/C plane motor (used, ebay, new, anything)?

    That's why people use weed eaters, it's cost effective, easy to do, and there are guides on how to do it that has been proven.

    I don't think you'll be pleased with the results for the cost though. But, it's your wallet, not mine. If you wanna do a large R/C motor, by all means - have at it.
  9. Wheres my dog

    Wheres my dog Banned

    Wait... I stand corrected here guys

    I was thinking of small, very small engines as he first mentioned... not knowing we were talking about 200 to 400 CC engines!

    Could be possible!
  10. DuctTapedGoat

    DuctTapedGoat Member

    Lol, same here.

    But, I'm not sure if it's a "save money" thing, or if it's a "i'm gonna do this cause I think it can be done thing". It's tough to say from what he's said. If it's the latter, there's no stopping him. :D
  11. ratdoggg

    ratdoggg Member

    I am talking about a 50cc with 4.5 horse power!!
  12. DuctTapedGoat

    DuctTapedGoat Member

    Is it going to be a cost effective motor, or is it a money is no option thing you're gonna do it to do it no matter what it takes to get it done thing?

    You're going to have to fab stuff up. As well, what do you expect your RPM to be off that motor? If you're talking about doing a friction drive, don't expect to take full advantage of the HP.
  13. schulze 123

    schulze 123 Member

    Hi Guys,
    This is just my 2 cents worth but hope it helps. I work in the Aeromodelling industry and have used various parts (carbies and exhausts) with good success. So for this topic I will use the DLE 55cc 2 stroke as the example.

    Pros - 55cc (similar to most MB engines)
    - 5.5hp at 7500rpm (excellent)
    - 1.5kg all up weight (excellent)
    - Torque figures not available but they swing a large coarse pitch prop
    - Great fuel economy (well in an aircraft :D)
    - Walbro carby (great mixture control)
    - Reeded induction (good for bottom end grunt)

    Cons - Virtually no suitable mounting points on the crankcase.
    - Crankshaft is only supported on one side, HT motor has both sides.
    - Attaching clutch/sprocket to the crank shaft very difficult as the
    shaft is very small in diameter and is approx 100mm from the only
    mount on the crankcase (bad for our application).
    - Ignition system albeit far more advanced than the HT, requires a
    separate power supply (4.8volts) to operate it.
    - The cooling fin area is less than 1/4 of the HT and would more than
    likely overheat (no forced air cooling from prop)
    - Supplied exhaust would be too loud (yes that can be changed)
    - Price $540.00AU (not good for the hip pocket)

    Conclusion - After spending a large amount of money buying the motor and then another bucket full adapting it to your bike, you will have a machine that will go like stink on the smell of an oily rag. Then when you're all smiles the thing rips itself out of the frame just as the crankshaft turns into a pretzel, the barrel distorts due to excessive heat and the spark gives out because you forgot to charge the ignition battery :evilgrin:.
    If this were an easy cost effective project I would have definitely pursued it as there are many of these motors available at my work.

    Again just my 2 cents worth as I hate to quell peoples enthusiasm.

    Cheers BJ

    Attached Files:

  14. HeadSmess

    HeadSmess Well-Known Member

    i still like the idea, but there is a major issue. friction drive. wont work. neither will direct drive.

    generating electricity on the go though...thats possible.

    envision, if you may, the OS rotary. a very expensive engine yes (about what i paid for my cnc mill giving me the capability of making my own:D )

    but anyways. at 5cc, this lil beastie can produce 1.2hp from memory.

    yes, yes, its tiny, runs on nitro, blah blah. and its a rotary!

    ha ha! running a generator, you run it at one rpm basically. just what rotors actually like.

    can we go back to the daydream please? ok.

    so you couple this here rotary to a large brushless motor. these work quite nicely as generators. there you are....

    yes, i have a mill. im basically thinking a 10-20 cc petrol rotary, combined with a smalll genny, ducted with a fan. a nice, compact cylinder... say the size of a drink bottle.

    i can make something like this with some time.

    then a decent E-hub, speed controller...

    but as one off's or low vol production...the price would be prohibitive. soz :(

    and quoting ratdogg

    I am talking about a 50cc with 4.5 horse power!!

    kx60....60 cc making probably 10 hp.....or more. been on one?
    Last edited: Jan 17, 2011
  15. loquin

    loquin Active Member

    Along the same lines (but a lot more practical) is the GP460... : 46cc, 4.2HP+ at 11000 RPM.

    $255 at DDM

    And, it has the cooling fan built-in, self-powered ignition system already there, standard clutch already there.

    Now, that being said, this is a very powerful motor for a friction drive application; another member has stated that they have this combination, and they're tired of the excess power spinning the drive spindle. (and, as a result, they're moving to BMP's chain drive jackshaft add-on)
  16. 5-7HEAVEN

    5-7HEAVEN Guest

    I ran a GP460 engine on a BMP friction drive. It ran great on one of my bikes, but loved to eat tires. On another bike, its appetite was so voracious that it ate a new tire in two weeks. Whenever I started the engine, the engine would scream and literally dig out a chunk of rubber. In a week or so, there was a divot every inch or so around the entire tread surface!

    Now I run a 460 with chain drive/shift kit. My rear tire look great, but now the engine has an appetite for 8-speed chains. :detective:
    Last edited by a moderator: Jan 19, 2011
  17. 5-7HEAVEN

    5-7HEAVEN Guest

    The GP460 has a very narrow power band. It does NOT like to climb steep hills with a single gear ratio. The 460 works VERY well with a shift kit or NuVinci hub.
  18. Tanaka40

    Tanaka40 Member

  19. 5-7HEAVEN

    5-7HEAVEN Guest

    How heavy is it, and what size clutch does it have?
  20. tjs323626

    tjs323626 Member

    (I have a solution for this problem. This link is for a subaru-robin that is now listed on ebay. I do not know if it will work but the engine is rated at 3.3 peak HP.

    That engine looks good. I would like to know which clutch fits it. I have 2 small Sachs engines I plan to use on bikes. The mounting and clutch will be a challange. The quality of the German engines is great.