interesting experiance, trying to blow up a china girl motorized bicycle !!

Discussion in 'Motorized Bicycle General Discussion' started by rogergendron1, Nov 21, 2013.

  1. rogergendron1

    rogergendron1 New Member

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    some of you may or may not know i am converting my beach cruiser to a 212 cc predy trike. and i have been tryng to blow my china girl by riding it like i stole it and reving the p!SS out of it !

    so wile i am doing this i would like to not that i have a grubee gt5 with a puch 70cc hi hi head and massive porting, i mean like as far as you can go ... actualy i cut right though the top of of the exhaust port to the fins raising it lol i fixed it by JB welding in between the 2 fins and then ported even further !!! the piston has been massivly ramped for exhaust and transfer ports, and i have a custo x chamber exhaust and a tunned cns carb with a long custom intake manifold.
    the fuel i run is 93oct mixed 40:1 and i add 1.5oz of lucas oil upper cylinder lube to the fuel.

    ok now its been 3 weeks so far ridding like this !!!! i do this to and from work and that is a 5 mile ride down long country back roads .
    i have been riding at WOT and i mean WOT !!!! fully open and reving as far as she will go and cruising along at 40 mph average with a 44t rear sprocket !!!!!!!!!!!!

    i mean i must have put 250 miles on her this way trying to blow it and she is still running strong ! its almost like she wants to run like this lol !

    so i pull my motor apart just a few hours ago and check to see what the damage is from all this super hard ridding ......

    see next post to cont.....
     
  2. Danschutz

    Danschutz New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    What a teaser!!!!!
     
  3. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    ok i get the top end all apart and look at the jug, piston, head, and plug..........

    What the heck ????

    it all looks perfect ! lol

    i meanthe plug is perfect color
    the jug looks clean no glazing no scraches, no scuffs
    the piston is clean, not to bad looking, no real scratches or scuffs
    the head combustion chamber is clean !

    so i grabbed at the dremal again thinking lol i will port the intake wide open to allow for way more fuel flow. so i did i ported it WIDE OPEN in an upside down D shape the flat of the D on the top of the port and the bottom of the D at the bottom of the intake port. i must have opened it up 3.5mm down from stock and 3mm wider over all leaving the roof ported as far up as i could go before exposing the bottom of the top piston ring lol about 1mm. the ports are now maxed out as a wide open top end race bike would have bolth are D shape ports (the exhaust D is faceing the top of the jug)
    then i ground the ramps as far up the piston as i could and made them wider and steaper .
    i drilled out the wrist pin even more lol its real thin now

    so i get it all back together and think this is it !!! a midnight ride to blow my motor !!!

    i get it running, with ports that big its hard to start in the cold. and they are so big now it cant get enough fuel to idle so i adjust the idle a full turn in to make it idle right . now that its tunned i go for a ride ....

    right off the bat once its running and tunned i hammer the throttle wide open and see whats up !!!! she takes off slow from a dead stop but she does take off faster than stock, so it looks like i lost some bottom end from the perfect preformance street tune i had before but still more power than stock .
    once i hit about the lower mid RPM's she started taking off like a rocket !!! she ripped down the street picking up speed faster than she did before and kept picking up all the way to around 40mph and hovered there ... this is on a stock 44t rear ! so i cranked on the throttle so it was ALL the way open and to my suprize there was no bogging but she sped up some more !!! lol i have no idea how fast i was going but i am dead shure DEAD SHURE i was going over 40 lol i passed cars going the speeed limit 35mph !

    man i rode the bike at WOT for 30 min non stop expecting it to blow and nothing lol
    so i rode home at all the way WOT for another 30min and nothing so i rolled into my back yard and shut her down and put my hand on the puch head .... nothing !!! not even hot lol i could hold my hand on the head !!!!!

    whats up here how long do you guys think this will take to blow like this ???
    any way more tomorrow....

    i will keep you guys updated on my china girl beat down untill she goes .
     
    #3 rogergendron1, Nov 21, 2013
    Last edited: Nov 21, 2013
  4. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    ohh and i di not take pics of the top end so tomorrow i will hammer down on her for a good hour at WOT and rev the crap out of it trying to pop wheelies and then go home and strip down the top end again to show my porting and the jug walls and the piston and chamber ...

    pics of the inside of the motor tomorow guys !!! i want to give another hour of **** to her !
     
  5. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    when i say WOT i mean WOT !!!

    just a few min ago i went faster than any human should ever ride a cheap 100$ beach cruiser EVER !!!! i was genuinly scared lol and it take a lot to scare me . that ride was the fastest i have ever gone on any bike ever ! 40 plus mph on a single speed beach cruiser from wal mart with only hub brakes is insane !!!

    i am going to down load the speedo app for my cell phone and clock my speed each ride at WOT to see if she starts loosing power over time or to clock my speed if she just goes instantly and i will start recording my top speeds for the day here .

    mabey some one can calculate my rpms for me ??? i dont have a rpm guage so i dont know ... but i do know its way up there for this type of motor !!! we are talking close to 10,000 rpms !!! it has to be !!! that my guess from the sound of it and the vib's given off from it . probably between 8,000 and 10,000 rpms srsly

    26in tire, 44t rear sprocket, stock front sprocket, 40mph = what rpm ???

    i may just get a mechanical speedo or a good digital speedo from one of the websites here, they are usefull to have anyway . mabey a temp guage too

    i want srs proof of speed that i can record and post and i also want to record speed at witch the motor blows or starts dieing at . my gues is it will go slower and slower easch day till its to scored and scratched to hold compresson then that will be all she wrote, but there is always the chance something gives or breaks and the motor blowes catastrophicly !!!
     
    #5 rogergendron1, Nov 21, 2013
    Last edited: Nov 21, 2013
  6. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    OK SOB !!! to go 40mph with a 44 t sprocket i must have been reving her close to 11,000 rpm!!!

    tire size 26in
    10 t drive and a 44 t rear = 4.4:1 rear axle ratio
    motor ratio is 5:1 reduced i think
    and speed was 40 miles an hour i believe ... i was passing cars going 35 !

    those numbers give me and engine rpm speed of 11,372 !!!

    using this calculator
    http://www.crawlpedia.com/rpm_gear_calculator.htm

    even if i say i was only doing 35, the same speed fo the cars i quickly passed the rpms would be ......... 9,951 !!!
     
  7. dodge dude94

    dodge dude94 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    My God you're one crazy SOB! :D

    Better you then the rest of us, but get some brakes on that thing please! You're a smart dude, no sense dying over this. lol
     
  8. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    I WANT TO SEE THIS THING BLOW !
    you guys have any ideas to get her to blow ?
    like riding up hill wot, or down hill wot ?
    no change of fuel mix though, i want to be fair ! keeping her at 93oct 40:1 mix with 1.5oz of lucas oil upper cylinder lube mixed per half gallon


    mabey even riding in a strait line at wot as fast as i can go and keep her there for as long as it takes ? 10 miles 15 miles who know lol i will have to recored it !!! i know she will do a full 2.5 miles at WOT as fast as possable then slow to a intersection and then right back to WOT for another 2.5 miles again without a prob

    i just can not believe this cheap motor is still taking the abuse !!! srsly i need to document this !!!

    how many rpms do race motors turn ? how many rpms are concidered safe for the china girl ? because i am dead shure i am turning well over 8,000rpm's ever ride and keeping her over 8,000 for 99% OF THE RIDE
     
    #8 rogergendron1, Nov 21, 2013
    Last edited: Nov 21, 2013
  9. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    yeh i know lol i have a set of side pull c type breaks, and a dual disk break setup is coming in the mail soon. the side pull breaks are going on the front tire tonight ! the dual disk breaks are for the rear axle.

    i plan on running a dual disk setup for the rear trike axle hooked to a single cabe via a Y connector and run to a dual pull lever so all 3 breaks front and bolth rear pull at once with a single lever.

    but i am setting up the front breaks tonight, i got real scared today and thought about what would happen if my chain broke or fell of or if my hub failed !!! that was all it took to convince mr to add the front now lol until a few weeks ago i just put around below 30 but now i am trying to blow thi thing and ride well over 30mph every time i ride so breaks are a must !
     
  10. Intrepid Wheelwoman

    Intrepid Wheelwoman New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    You know she's only doing this to spite you ;)
     
  11. Russ McClay

    Russ McClay New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    Very interesting experiment, rogergendron1!
     
  12. BonusParts

    BonusParts New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    You're wasting time trying to blow it up. I've learned one thing that IS constant with ALL HT style motors: If you baby them they break. If you flog them like a donkey they dont quit. I rode mine full bore for 30 miles missing an exhaust stud, and it was HOTTTT, but no issues. still runs great, does 40+ on the reg.
     
  13. MotorBicycleRacing

    MotorBicycleRacing Active Member

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    Re: interesting experiance, trying to blow up a china girl !!

    Your rpm's at 40.7 mph are 9500

    20 tooth bevel gear to 82 tooth clutch gear = 4:1 to 1

    Did you measure your tire diameter?
    Most cruiser tires are 26.5" diameter which would make your RPM's 9,300

    If you were going 35mph your RPM's were 8100
     
    #13 MotorBicycleRacing, Nov 21, 2013
    Last edited: Nov 21, 2013
  14. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    Thank you ! Can you help me acuratly measure engine rpms ?

    Whats the motor gear ratio at the small sprocket?
    Whats the gear ratio with a 44t rear ?
    Tires are 26 in

    So if i was going 40 with 26in tires and a44t sprocket my rpms were 9,300 ? Than i should be able to make a larger diamiter and shorter intake manifold and gain a few more rpms ! I want to break 10,000 and the motor ! Lol and i want it on record via video and speed recorded by app or gps . Mabey i will mount my gps on my bars and video the ride for proof of speed and rpms from math . I want to see if i can psh 11,000 before she blows ! I am real close to 10,00 now so with the larger porting and mabey a larger and shorter intake than the off set one i am running now i can get her there. I have a cns carb 16mm, offset z intake, and major porting and piston mods with a puch 70 high high head . I can run at 9,000 rpms no problem for miles ! I wonder how well reed valve setup would help gain rpms or if its just helping meter fuel and block of the intake at the down stroke .
     
    #14 rogergendron1, Nov 21, 2013
    Last edited: Nov 21, 2013
  15. rogergendron1

    rogergendron1 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    Going to go for a ride tonight to stress her some more willl fo a video of wot high rpms
     
  16. Stormsorter

    Stormsorter New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    Here is a link to the calculator most of us use. I use it so much I've actually forgot the equation to do it myself.

    http://jimsitton.net/ratiocalc/

    Just click gearratio.exe on that page to download it.

    And MotorBicycleRacing already gave you the other info you needed in his last post.
     
  17. racie35

    racie35 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    use no oil next fill-up problem solved
     
  18. slayer60973

    slayer60973 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    I want the head after if It isn't destroyed!!!!
     
  19. dodge dude94

    dodge dude94 New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    That's why my engine sounds so pissed off at me occasionally. lol
     
  20. massdrive

    massdrive New Member

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    Re: interesting experiance, trying to blow up a china girl !!

    I knew a guy with a 1970 302 cu in Ford Econoline van with 200k miles on it. Same thing he could not blow it up so he wedged a brick on the gas peddle with a broom stick and left it floored in park for 30 minutes. He couldn't take the roar of the engine anymore and shot it off! The next day he gave it to his step brother who put another 100k on it and gave it to his nephew. Lost track of it after that, for all I know it may still be running...

    Try pegging the throttle with the clutch in. Just be careful when she does blow it may do some collateral damage. May do it in a open field or something...
     

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