Performance 80cc

Discussion in '2-Stroke Engines' started by NBP MotorSports, Dec 11, 2010.

  1. NBP MotorSports

    NBP MotorSports New Member

    Ok, I have searched and really didn't find what I want to know. Here it goes.
    Building a "Motored Bike" more for show and speed.
    Has anyone used R/C racing fuel? Is it cool to run it instead of gasoline?has anyone bought parts from
    I want to build something like a drag bike.

    This is what I'm starting with;

    Attached Files:

    Last edited: Dec 11, 2010

  2. motorpsycho

    motorpsycho Active Member

    well, no...r/c racing fuel is 20% nitromethane and it is closer to diesel fuel than it is to gasoline.
    to run nitro, you need a heck of a lot of compression and a major ignition system to fire the nitro. r/c racing fuel is not like the nitro that is used in a top fuel dragster.
    r/c nitro has a lot of oil content and an r/c engine fires the nitro on compression, there is no spark plug. (like a diesel) it has a glow plug with is there to heat up the cylinder not so much to ignite the fuel. these little engines don't have a ton of compression, and all you need is 87 octane gas. even if you go with a hig compression head,k the compression still won't be high enough for nitro.

    if you want low end torque and decent top speeds, you should consider going with a shift kit, milling the head,(or go with a high compression billit head) putting on a cns type carb, a billit intake, port and polish the intake and exhaust, an expansion chamber, upgrade to an 8 mm spark plug wire with a rubber boot, an ngk spark plug and a high flow air filter. and if you still need a little boost, you could put a nitrous kit on it, but i'm pesonally not sure how well they work.
    there are a lot of things that you can do to these little engines to get more power out of them.

    you can increase your top speeds by going with a shift kit. a shift kit will give you the best of both worlds...low end for take off, and top speed. i think a shift kit or gearing (for single speed bikes) is one of the simplest ways to get more speed out of one of these engines. but if you just change the rear sprocket to a smaller one, you will lose torque for take off. that's why i mention a shift kit. besides, what can be cooler than banging through the gears on a bicycle with an engine on it?

    I like what your thinking tho, and a drag bike would be awesome looking if it's done right.
    so, i think you would be able to give the engine some more power to go along with the drag bike looks, but don't expect too much out of it. I have heard claims of bikes being able to go 52 mph with shift kits on them, with stock engines, but i have no idea how true that claim is. you should also consider a major brake upgrade too if you are planning on trying to get into the 50 mph range. disk brakes would be the way to go.
    I want to build a drag bike too, but i want to do it with a stretched and lowered 20" frame.

    I'm not an authority on this subject, i'm just offering some suggestions based on things i have personally done to one of these engines, and things i have read about.
    Last edited: Dec 11, 2010
  3. NBP MotorSports

    NBP MotorSports New Member

    OK, so the Nitro fuel is out. I have looked at the NOS system, wet and fogger. I hear that the wet system is better for the motor than the fogger. Butt... the wet system is $350-$600, and the fogger is $40.
    Now the carburetors I'm looking at start at $69-$290.
    I haven't found the tranny for it yet, but that would be something I would like to add.
    I'm also looking for a kick start too(if they make it for this type of motor).
    I think I'm going to port and polish the head today. Clean it up a little for better airflow.
    I'm working on a "tornado" spacer to help atomize the air/fuel mixture better.
  4. NBP MotorSports

    NBP MotorSports New Member

    Has anyone used the NOS kit?
  5. NBP MotorSports

    NBP MotorSports New Member

  6. ibdennyak

    ibdennyak Guest

  7. motorpsycho

    motorpsycho Active Member

    it's not saying that it will give you 125 horsepower, it's saying that it can support up to 125 horsepower.
    I'm starting to wonder how well this would work on one of the h.t. engines.
    or would it be a waste of $$?
    it sure would look and sound cool on a bicycle tho.
  8. NBP MotorSports

    NBP MotorSports New Member

    LMAO... It would probably be a waist of money. But I think I might get one to play with. Come on, its a "TURBO"!
    Last edited: Dec 13, 2010
  9. motorpsycho

    motorpsycho Active Member

    yeah it would be fun and it would get you lots of compliments just by it's looks.
    sometimes, form wins over function in my book.
    but it is expensive, you could buy 2 new complete engines for what it costs.
    who knows, maybe it would even add a little bit of power.
    any little bit helps with these engines, but would the gain(or possible no gain) justify the price?
  10. geebt48cc

    geebt48cc Member

    Yes, I've got a 475 hp snow blower .................... Hard to hold, but does a great job.............!
    Last edited: Dec 14, 2010
  11. motorpsycho

    motorpsycho Active Member

    i still think it's a pretty good idea, but i have no idea how it would actually work.
    i think it is possible for it to add some amount of power, but not a whole bunch.
    I don't think it would make an 80 c.c. engine run like a 200 c.c. engine.
    but, anything is possible and as long as the turbo is sealed, as well as the entire intake tract, adding compressed air to any engine will make more power.

    but i am a little confused on how it would work on a 2 stroke because the fuel-oil mixture goes into the crankcase before it goes into the cylinder.
    so would this compressed air hurt anything in the crankcase?
    i realize that it would not be like blowing 100 psi of air into the crankcase, but i'm wndering if it could cause any prpblems with the bearings or the gaskets due to too much pressure?
    i wonder just how much psi that little blower can put out.
    man, i know it's crazy and expensive, but i am very surious about this little thing and i am wondering how well it actually works.
    The gear head in me is being curious, and as the search for more power in these engines is ever increasing, a turbo makes a little bit of sense to me.
    i wish that someone neutral who actually has one of these turbos would put a video out there telling everyone if it's good or bad.
    i still can't get over the price's too expensive for me to justify buying one.
    if it was a lot cheaper, i'd buy one just to see how it would work.
  12. NBP MotorSports

    NBP MotorSports New Member

    Welcome to my world. I've been searching the web to see if I can find one, but no.
    If you think about it, would the 80cc be able to spool it up? Isn't the exhaust and intake at the same level? Would you lose all the power every stroke? How much pressure will the turbo spool up? Will it blow the head off? So many questions!
    How about;
    Electric blower motor forcing air when you flip a switch?
    H2O fogger?
    Just some food for thought.
    Last edited: Dec 14, 2010
  13. motorpsycho

    motorpsycho Active Member

    yes, the intake and exhaust ports are at the same level on the cylinder. you woudl have to custom make an exhaust to feed into and out of the turbo. you would think that there would enough exhaust pressure to spool the turbo up as long as the exhaust is 100% leak free. having a sealed, non leaking exhaust, and a sealed, non leaking intake would be partially the key to making this thing work. you would need every ounce of exhaust getting into the turbo to spool it up and every ounce of intake air getting into the engine to get any power.
    in theory it would work, but i am still curious as to the effect of the compressed air going into the crankcase before it goes into the cylinder.
    i'm thinking that it would be fine, but would that take away from the effect?
    you need to cram as much air into the cylinder as possible with a turbo, and by the air going into the crankcase first, would it have the same results as if it were going dorectly into the cylinder?
    curiosity is getting the best of me, and if i had a couple hundred $$ laying around collecting dust, i'd just buy one and see how it works on one of these engines.
  14. motorpsycho

    motorpsycho Active Member

    good point.
    is is possbile that this little turbo would make enough boost pressure to blow the head right off the engine with the stock head studs?
    an electric blower motor would probably not work. it would need to put out A LOT of air, and it would need to be in a totally sealed set up to gain anything from it. a blower motor can move air, but it can't create compressed air unless it is in a sealed case or something. if there is a way to get the air compressed, you would need a pretty big blower motor to get any effect out of it in my opinion. this is why the compressor wheel blades are shaped like they are in a turbo the shape of the blades, the number of blades and the sealed case is what compresses the air.
    after all a turbo is just an air pump, but the way the compressor wheel blades are designed is what makes it work.

    H20 fogger? (H20 is water)

    this is crazy!! we are tallking about a turbo for an 80 c.c. 2 stroke...we have too much time on our hands! :)
    Last edited: Dec 14, 2010
  15. NBP MotorSports

    NBP MotorSports New Member

    Way too much time!
    I'm planning on building this bike and taking it to the Shriners Temple for an auction. All the proceeds go to the Shriners Children Burn Hospital. Now with that in mind, I'm going to call the company that makes the turbo(or the dude who is selling it) and see if they could donate it or give me a good price break. hopefully that will work.

    With the fan, look at it this way;
    When you go to the drag strip, make a couple of passes with no wind, you have average time slips. Now you have a head wind, your forcing more air into the carb(not much, but enough), your going to shave your time down. So your picking up a little HP, MPH and helping the MPG. Not much, but a 0.01 will win a race. Its like a K&N cold air kit, with a fan.

    :idea:H2O fogger(injector);
    Your atomizing water, say 1/4th of a teaspoon. mix that with air and fuel(heat), compression, you have a steam/fire explosion(in theory). Im still working on this one. Im going to try it out on the lawnmower first.
  16. motorpsycho

    motorpsycho Active Member

    oh ok, so you're talking about water injection. i thought you typed it in wrong, and you were trying to refer to nitrous oxide (N2O).
    they did make water injection kits for v-8 race engines a long time ago, but i have no idea if anyone still makes them, so, in theory it can work and is supposed to help stop pre-detonation in the cylinders.

    you're referring to a ram-air effect (like on pontiac gto's) and it does work. the key is cramming as much cold air into the intake as possible, but i'm not sure how a fan would work. any time you can reduce the temp. of the intake air, you will build power. cold gas and cold air going into a hot engine will make some more horsepower.
  17. NBP MotorSports

    NBP MotorSports New Member

    Well I think I am close now. I have all my parts except for the rims, and they are the most important part of the build:confused: . So....I need to save a couple three hundred for Surley Large Marge rims.:grin5:

    I have a few of questions about the 2 stroke;
    Difference between the carbs?
    Where do I get a USA 2stroke?
    Are they that hard to tune and keep running?

    I have been reading alot of the posts and its alot of; "it wont do this", "its doin that" and alot of "I cant...".
    Is there a Forum that has "POSITIVES"? :thinking::thinking::thinking:
  18. adb140275

    adb140275 Member

    RC nitro ignites very easily, but detonates like mad. you DO NOT want to run nitro. just dont do it

    I've run nitromethanol in a few small two stokes before, it eats fuel line made for gas (just as gas eats silicone line)

    it does not require a lot of compresssion at all, I can get a weedeater engine to diesel on the stuff (run with no ignition when hot)
  19. RdKryton

    RdKryton Active Member

    I don't want to be negative but there are just some things that will not work. Simple laws of physics prevent you from ramming air into the engine through the carb. These carbs all need vacuum to draw fuel up through the metering jets. If you have enough pressure you will shut off the fuel flow from the carb. With a scoop on the air cleaner you probably won't get enough air to shut off the fuel but you will lean out the mixture. This will give a small performance boost but at a cost. (lean=heat) Heat will kill these engines real fast. Another problem with the turbo that I see is with a 2-stroke engine you do not have a pressurized oiling system. Without oil flow through the turbo, it will fail almost immediately. But hey, best of luck with your project. I would love to be proven wrong.

    Last edited: Dec 21, 2010
  20. motorpsycho

    motorpsycho Active Member

    wow, i never thought if that!
    a turbo needs pressurized oil to feed the bearings, and without it, it will lock up in no time.