Survey by Qualaroo
+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 20 of 22
Like Tree10Likes

Thread: Bikes Labelled 78 cc are not 78 but 88cc or rather 90cc bikes

  1. #1
    Senior PakWheeler Follow
    asjdsm's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    30
    Posts
    3,470
    Follows
    4
    Following
    0
    Mentioned
    57 Post(s)
    Tagged
    3 Thread(s)
    Problems Posted
    0
    Problems Solved
    1
    Best Answers
    0
    Good Answers
    0

    Default Bikes Labelled 78 cc are not 78 but 88cc or rather 90cc bikes

    hi
    today i opened my engine of dhoom yd 70 to solve the mystery of its bore and stroke size .. eventually calculate its true displacement in cc.
    the results were stunning
    i used vernier calliper to do this experiment
    the bore came out to be 46.8 mm or rather say 47mm
    and the stroke calculation was a bit tricky as the piston was not flat it had a lot of surfaces and that was giving different values at differnt points.

    however if calculated from the place of higer posion on piston the stroke was 50mm... and this depth is not from the top face of cylinder rather from the point whre the piston reaches at its TDC ..

    Now using formula foir cc calculation
    cc= bore^2*stroke*.7854 [bore and stroke r in cm]
    cc=4.7^2*5.0*.7854
    cc=86.7cc

    now despite being an 88cc their top speed is 80 mostly on flat road.. mostly ..and what i have noted is that they have very hard time in climbing whareas honda cd 70 has also got 80 as top speed and its climbing ability is awsome..

    so where is the bottle neck in these CHondas...?


  2. #2
    PakWheeler Follow
    Junaid_riaz's Avatar
    Join Date
    Oct 2009
    Location
    Faisalabad
    Age
    39
    Posts
    107
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    yd dhoom is Chinese bike not original parts or workman ship of Yamaha Japan, so no comparison with Honda CD70
    However Junoon is original bike of Yamaha So you may see the difference its best in 100 cc category.

  3. #3
    PakWheeler Follow
    cursedd's Avatar
    Join Date
    Jan 2007
    Location
    Karachi
    Posts
    765
    Follows
    0
    Following
    0
    Mentioned
    7 Post(s)
    Tagged
    2 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by asjdsm View Post
    hi

    Now using formula for cc calculation
    cc= bore^2*stroke*.7854 [bore and stroke r in cm]
    cc=4.7^2*5.0*.7854
    cc=86.7cc

    whats this .7854??
    3D Printers | 3D Printing | Biotechnology
    www.grit3d.com

  4. #4
    Senior PakWheeler Follow
    asjdsm's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    30
    Posts
    3,470
    Follows
    4
    Following
    0
    Mentioned
    57 Post(s)
    Tagged
    3 Thread(s)
    Problems Posted
    0
    Problems Solved
    1
    Best Answers
    0
    Good Answers
    0

    Default

    pi/4
    the equation is size in cc= bore *bore*stroke*pi/4 [ or pi/4 is constant = .7854]
    for instance for honda cd 70
    cc=4.7*4.7*4.15*.7854
    cc=72cc

  5. #5
    PakWheeler Follow
    h3llzang3l's Avatar
    Join Date
    Jan 2011
    Location
    Multan
    Posts
    76
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Why we are not promoting the bikes which are made in Pakistan .... and about climbing its not the bike its the rider ... if you r a good rider you can climb with 50cc or if you r not you can't even take the 125cc bike on country side rods .... and for your kind information i have beaten the Honda cd 70 with the loaded weight of 80kg where i am using Habib with the loaded weight of 130 kg ... so it snot the bike its the rider

  6. #6
    Senior PakWheeler Follow
    asjdsm's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    30
    Posts
    3,470
    Follows
    4
    Following
    0
    Mentioned
    57 Post(s)
    Tagged
    3 Thread(s)
    Problems Posted
    0
    Problems Solved
    1
    Best Answers
    0
    Good Answers
    0

    Default

    ^^ o bhai ya 70cc motorcycles hain koi Fighter Jets nahi jin ka lia experienced pilot chaiya...
    i have tested 3 honda cd 70 and almost half a dozen chondas till this date in murree and that is y i am saying this fact..

  7. #7
    PakWheeler Follow
    h3llzang3l's Avatar
    Join Date
    Jan 2011
    Location
    Multan
    Posts
    76
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    So we don't even want to promote the Pakistani Made Bikes ... Then we never have the names like Harley Davidson , Boss Hoss known as American Muscle Bikes .. ok we made JF17 Thunder with the Help of China so what do you said its also the GF17 (Girl Friend of F17) ... Fine Fine Fine .... and i am not against the Honda or other International Brand .. but we should also respect the Local Brands..

  8. #8
    PakWheeler Follow
    cursedd's Avatar
    Join Date
    Jan 2007
    Location
    Karachi
    Posts
    765
    Follows
    0
    Following
    0
    Mentioned
    7 Post(s)
    Tagged
    2 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    and sir jee where u get this eqauation from??
    3D Printers | 3D Printing | Biotechnology
    www.grit3d.com

  9. #9
    Senior PakWheeler Follow
    asjdsm's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    30
    Posts
    3,470
    Follows
    4
    Following
    0
    Mentioned
    57 Post(s)
    Tagged
    3 Thread(s)
    Problems Posted
    0
    Problems Solved
    1
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by h3llzang3l View Post
    So we don't even want to promote the Pakistani Made Bikes ... Then we never have the names like Harley Davidson , Boss Hoss known as American Muscle Bikes .. ok we made JF17 Thunder with the Help of China so what do you said its also the GF17 (Girl Friend of F17) ... Fine Fine Fine .... and i am not against the Honda or other International Brand .. but we should also respect the Local Brands..
    bhai la tho li ha so called pakistani bike,, ab our kaisa promote karoun,,,?
    the bold text is not said by me don't put words into others mouth,, for the use of word chonda ,, google it ,, or just wiki it,,,,u will come to know,, and for the word GF 17 .. thats is ur own creation not mine.,,

    or here is the wiki refrence to the entry chonda
    http://en.wikipedia.org/wiki/Chonda

    @cursedd
    knowledge of basic geometry in enough to calculate the volume of cylinder,,oh if have studied integration it will also give u the exact equation,,google for more info
    calculate displacement for single cylinder engine in cc

  10. #10
    PakWheeler Follow
    cursedd's Avatar
    Join Date
    Jan 2007
    Location
    Karachi
    Posts
    765
    Follows
    0
    Following
    0
    Mentioned
    7 Post(s)
    Tagged
    2 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    ohh so its application of integration..then this equation thing is really to do a thing with me..coz nowadays em' learning integral calculus. inshallah will understand this!
    3D Printers | 3D Printing | Biotechnology
    www.grit3d.com

  11. #11
    Senior PakWheeler Follow
    asjdsm's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    30
    Posts
    3,470
    Follows
    4
    Following
    0
    Mentioned
    57 Post(s)
    Tagged
    3 Thread(s)
    Problems Posted
    0
    Problems Solved
    1
    Best Answers
    0
    Good Answers
    0

    Default

    its double integral in cylinderical cordinates in Calculus 3,,

  12. #12
    PakWheeler Follow
    cursedd's Avatar
    Join Date
    Jan 2007
    Location
    Karachi
    Posts
    765
    Follows
    0
    Following
    0
    Mentioned
    7 Post(s)
    Tagged
    2 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    ohkk.. i'll get to learn it when i'll learn the surface integral and now em studying line integral.
    3D Printers | 3D Printing | Biotechnology
    www.grit3d.com

  13. #13
    PakWheeler Follow
    outlaw92's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    24
    Posts
    220
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    @asjdsm
    Bhai meet me and i'll let u test ride my hero rf 70 2011.No alterations whatsoever and bike climb's like a 125.Tested on the roads of peer sohawa.It all depends on the setting.This is the term that mechanics use and even i dnt understand.My mechanic took abt 2k for this setting i wached him do it.He was meddling a lot with carb and tappet settings that's all i can tell u.
    To personally satisfy my own adrenalin needs, I've been racing Bikes a little bit, which has been fun.

  14. #14
    Senior PakWheeler Follow
    asjdsm's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    30
    Posts
    3,470
    Follows
    4
    Following
    0
    Mentioned
    57 Post(s)
    Tagged
    3 Thread(s)
    Problems Posted
    0
    Problems Solved
    1
    Best Answers
    0
    Good Answers
    0

    Default

    i can do carb settings,,and they matter a lot,,i say a lot.. now i m not free but when i get some time to visit mmurree i will adjust the carb and share those tips/tricks with u ppl,,

    regarding tappets settings i will have to check them,, but again the only setting done to tappets is its clearance..
    after tuning u could easily reverse engineer his settings .. just check what the clearance is and also what the carb is set to.. i.e. what number of jets r placed and how is the placement of needle in the grooves..

    also dear can u tell me what are the main and pilot jets of ur hero carb ? is it the one labelled pz22 ? i have purchased one replica of this carb it has jets but not labelled can u help me by telling me what are the primary and secondary jets..

  15. #15
    PakWheeler Follow
    outlaw92's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    24
    Posts
    220
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    @asjdsm
    Yes i remember him talking about jets or something.He said that older model's i.e 2010 2009 etc had jet size 72 i think and my bike had a built in jet of size 75.Anyway's what he was saying that new model has bigger carb jet's.Regarding ur question i will ask my mechanic and answer u soon.
    To personally satisfy my own adrenalin needs, I've been racing Bikes a little bit, which has been fun.

  16. #16
    PakWheeler Follow
    umer009's Avatar
    Join Date
    Dec 2009
    Location
    Lahore
    Age
    29
    Posts
    702
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by outlaw92 View Post
    @asjdsm
    Bhai meet me and i'll let u test ride my hero rf 70 2011.No alterations whatsoever and bike climb's like a 125.Tested on the roads of peer sohawa.It all depends on the setting.This is the term that mechanics use and even i dnt understand.My mechanic took abt 2k for this setting i wached him do it.He was meddling a lot with carb and tappet settings that's all i can tell u.
    like a 125? no way man there is a hell lot of difference in engines of 70 &125,
    regarding 2k, i think he cheated u coz car tuning costs RS 500 maximum

  17. #17
    PakWheeler Follow
    outlaw92's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    24
    Posts
    220
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    @umer009
    As long as i'm satisfied with the performance of my bike i dnt think he cheated me and i think the way my bike is performing right now 2k is definitely worth it.Ur right tuning costs 500 max par mein nay tuning nai karai thi aur bhi kaafi kaam karaya tha eg alignment wheel balancing etc etc...
    To personally satisfy my own adrenalin needs, I've been racing Bikes a little bit, which has been fun.

  18. #18
    PakWheeler Follow
    outlaw92's Avatar
    Join Date
    Apr 2009
    Location
    Islamabad
    Age
    24
    Posts
    220
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    @umer009
    No matter what you do u cant reach the performance of 125 but like asjdsm i go a lot to murree peer sohawa and other hilly areas and bike climb's very very easily almost the same result as 125.
    To personally satisfy my own adrenalin needs, I've been racing Bikes a little bit, which has been fun.

  19. #19
    PakWheeler Follow
    umer009's Avatar
    Join Date
    Dec 2009
    Location
    Lahore
    Age
    29
    Posts
    702
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    to get u an idea , an engine overhaul for 70 cc costs 1500 of labour maximum
    anyways its ur bike and as long as ur satisfied its ok , good luck

  20. #20
    PakWheeler Follow
    osama0333's Avatar
    Join Date
    Dec 2010
    Location
    Karachi
    Posts
    9
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Cool

    hahaha guys if u alter ur piston and valve also than also u cant reach at the performance of 125cc.cause thr iz not only change in size piston ,carb,valve,weight,spockets , are too differ....chchchchc......i think k agr aisa hota to company b 2k 70cc k upr lga k kehti lo g 125 hazir hai janaab

+ Reply to Thread
Page 1 of 2 12 LastLast

User Tag List

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •