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How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me sugg

  1. Mar 22, 2009 #1
    I took an engine out of a snow blower (a 100cc-4hp-2 stroke) and was planning on hooking a turbine/fan assembly from a leaf blower, up to the carburetor. I plan on taking a 200/300 watt electric motor with a speed controller (HOOKED UP TO TWO 12VOLT 12Ah RECHARGEABLE SCOOTER BATTERIES) and connecting it with a 60 tooth pulley attached to the electric motor and a 12 tooth pulley to the turbine/fan so the ratio would make it spin fairly fast.

    I would mount the snow blower engine on the end of an electric scooter and mount the supercharger on the side then run some sort of tube/pipe to the carburetor to the turbine. The electric motor would also be mounted to the side of the scooter and would connect to the turbine/fan pulley with a belt. The batteries would be under and inside the scooter. *The supercharger would most likely be used to add acceleration upon take off opposed to using it at the engines max power for top speed.

    Do you think it will work?
    Any thoughts or suggestions?
     
  2. jcsd
  3. Mar 22, 2009 #2

    Danger

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    Welcome to PF, Asnipit.
    I have some serious doubts about this, but I'm not an expert.
    First of all, determine what the cfm capacity of the blower is. It might not deliver much more than the engine breathes normally. Remember that gearing the fan up from the motor won't result in a corresponding increase of airflow because the drag on the system will force the motor to work harder. If it turns out that you can get some significant boost, check with the engine manufacturer to make sure that the parts can take the stress. It's unlikely that a snow-throw engine has things like a thick-top piston, strong con rod, or premium bearings that a blown engine requires.
     
  4. Mar 22, 2009 #3
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    I agree...Since the engine was used for a snow blower, it doesn't have an aftermarket following and im sure its not meant to handle extra air into the engine. What specific modifications do you think i would have to do in order for the engine to be able to hanlde a supercharger?
     
  5. Mar 22, 2009 #4
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    A supercharger or turbocharger adds power by increasing the combustion chamber pressure. Therefore, any components directly influenced by that pressure need to be looked at -- head bolts, piston, connecting rod, rod journal, crankshaft, main journals. After that, just follow the flow of power transmission.

    It's impossible to offer specific modifications without knowledge of the engine you are using.
     
  6. Mar 22, 2009 #5

    Danger

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    My most serious recommendation in this instance, for the sake of both simplicity and economics, is to simply get yourself a bigger engine to start with. It'll save a lot of hassle.
     
  7. Mar 22, 2009 #6
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    I thought about it but im trying to use what i already have, to save money. I got the snow blower engine for free. I would like to first see if i can make modifications to the engine so it can be supercharged and save some money before i go out and buy a new engine. Its a fairly big engine (100cc 4hp) compared to most gopeds/gas scooters which have between a 25cc and 49cc engine.
     
  8. Mar 22, 2009 #7

    Averagesupernova

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    I say try it if you want to. Sure you could blow it up, but it might be fun trying right? It was free right? It might be a waste of time and effort and maybe a few pennies in driving the blower but if you have considered all of the downsides and still have the desire to do so then I say do it.
     
  9. Mar 22, 2009 #8

    Danger

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    I certainly agree with ASN that experimenting with stuff like this is the best way to learn as long as you're willing to risk failure. I've blown up a lot of **** in the past, and gained knowledge every time.
    Another thing to look into is your local laws concerning such vehicles. Powered scooters are illegal where I live.
     
  10. Mar 23, 2009 #9

    Ranger Mike

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    Whoa there pardner!
    you may be at risk of seriously messing up the engine..here is why
    some two strokes use a reed valve that premits entrance of the fuel/oil mixture. it is a thin steel plate that opens when engine vacuum sucks on the intake cycle...it closes as the piston compresses, thus sealing off the intake..the reed is designed to operate with normally aspriated engines..turbo/supercharge would pressureize the reed to open position
    there are other design two cycles so research and fundemental knowledge of operation is a must before modifying

    old go kart guys amped up the H.P. with lots of trick porting and other modifications..more compression etc..you may be able to modify the 4 hp to 8 or ten...
    option 2 - run it on alcohol
    3. NITRO????? its been done before...
     
  11. Mar 23, 2009 #10
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    I probably wouldn't use a nitros kit (although its not totally out of the picture) because it would be a temporary speed boost, expensive, and would be hard to find a place to refill. I've thought about it and it would be pretty sweet to do but the nos would not last that long opposed to the electric supercharger hooked up to 2 12volt 12ah scooter batteries. Using the electric supercharger i would be able to stop/turn off, increase, and decrease the speed of the turbine because its hooked up to a speed controller.
     
  12. Mar 23, 2009 #11

    Ranger Mike

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    Not nitrous....nitro
    As in same stuff top fuel dragsters run
    We ran it in a go cart
    Instant hp
    But about $100 a gallon these days
     
  13. Mar 23, 2009 #12
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    So since superchargers don't work much on 2 stroke engines because the exhaust ports are open at the same time as the intake ports are, is it possible to build pressure in the cylinder using a supercharger?
     
  14. Mar 23, 2009 #13

    Ranger Mike

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    Yes
    If no reed valves
    Are used
    If the mill is timed via port exposure
    U may be ok
    We amped up the 2 stroke by
    Cutting wider ports
    Go for it...
    If some is good
    And more is better
    Then too much is just enough- stroker mcgurk 1947
     
  15. Mar 23, 2009 #14

    Danger

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    Aye aye on that, Mike. Horsepower is like sex, money, and firepower; more is better and too much is just right. :biggrin:
     
  16. Mar 25, 2009 #15
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    You need an expansion chamber exhaust. It is truly magnificent invention. It consists of a convergant and divergent cone. The divergant cone causes a negative pressure on the exhaust sucking fuel/air mixture into the header. The convergant cone causes a positive pressure whith crams the fuel rich exhaust back into the chamber under presure. The length of the chamber is such that the returning wave is syncranized to arrive at exhaust port just before the exhaust ports are closed. It is a super charger with no moving parts, INGENIOUS. Expansion chambers are standered on mondern high performance two stokes. I had the equations for building one once, I found them on the web. It was just simple math and easily measurable dimentions from your engine.

    jslade
     
  17. Mar 25, 2009 #16
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    you need a compressor not a fan to supercharge
    a leaf blower will not work to compress air
    it is just a fan

    twostrokes and add on superchargers doNOT go well
     
  18. Mar 25, 2009 #17
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    I still think i could get pressure using a leaf blower fan assembly. If the air is being pushed into the tube/pipe that would be connected from the leaf blower to the carberator, then i think the air would be forced into the intake. The fan would be spinnning at high rpm's so i think it would compress the air enough to make a speed boost but i don't know that for a fact because i haven't tried it yet, and i haven't had much time to work on it.

    Heres a pitcture of the leaf blower fan and cover to show exactly what im using...
     

    Attached Files:

  19. Mar 25, 2009 #18

    Danger

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    If you're planning to blow through the carb rather than suck through it, you have to rebuild the carb first. They're not made to take an overpressure from the outside. You'll have to build some sort of 'hat' to place over it.
     
  20. Mar 25, 2009 #19

    Averagesupernova

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    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    A 2 stroke first draws the fuel/air charge into the crankcase through reed valves. The reed valves are to allow the fuel/air charge to enter the crankcase but to keep it from being pushed out as the piston pushes downward. When the piston uncovers the exhaust port the exhaust leaves the combustion chamber, however, some is left. A bit farther down on the stroke the piston uncovers the intake port which allows the compressed fuel/air charge into the combustion chamber from the crankcase. The crankcase compressed the fuel/air charge so it readily flows into the combustion chamber. Upon entering it helps expel any remaining exhaust.
    -
    Ok. I know the above is basic stuff that everyone on here already knew, but the point was to illustrate that if we have a blower pushing fuel/air charge into the crankcase while the intake and exhaust port are uncovered, there is nothing to stop the fuel/air charge from blowing right through the whole engine. I fail to see how anything can be gained unless some serious re-engineering of the exhaust system can be done to prevent what I described from happening.
     
  21. Apr 9, 2009 #20
    Re: How can i make supercharger for 4hp-100cc-2stroke-engine?got idea please give me

    Does noone see the beauty of the expantion chamber exuast?
     
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