Author Topic: CC swept area calulation  (Read 2757 times)

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Offline Tim754

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CC swept area calulation
« on: April 29, 2013, 06:34:43 PM »
 Here ya go. 

Bore x bore x .7854 x stroke x number of cylinders.  The bore size MUST ALWAYS be first in this equation , The figure of . (that's point)   .7854 is a constant in all cc calculations.

So a standard Honda CB750 K2 is 736cc  being each bore 61mm and stroke 63 mm ,,   therefore  it is ,,     61 x61 x .7854 x 63 x 4 = 736cc   Easy when ya know the maths hey!

Did you know 1 kilogram = 1 litre of pure water at sea level ;)
« Last Edit: April 29, 2013, 06:38:57 PM by Tim754 »
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Offline lukeb1961

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Re: CC swept area calulation
« Reply #1 on: April 29, 2013, 07:40:29 PM »
I strongly prefer to think of it as (Pi x (Radius squared)) x stroke, when discerning the swept volume of the cylinder.

[Radius being half the bore]
[Pi being the ratio of the circle circumference to its diameter, or (C/D) which is approximately 3.14159]
[(Pi x (Radius squared))] being the area of the top of a cylinder
[stroke being the length of the cylinder traversed by the piston]

then just multiply by the number of cylinders your engine has.

Your RM465 is  86mm (b)  x  80mm (s) 
( ( 3.141592654 * ((0.5* 86mm bore) * (0.5* 86mm bore)) ) * (80mm stroke) ) * 1 (single cylinder)

ergo = that standard bore RM465 is indeed 464.7cc



Offline Tim754

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Re: CC swept area calulation
« Reply #2 on: April 29, 2013, 07:45:53 PM »
Take your pick kiddies   which bit to end up with the same sh......... ;)
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Offline brent j

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Re: CC swept area calulation
« Reply #3 on: April 29, 2013, 07:53:07 PM »
What makes Tim's method easy to remember is the .7854 is the four numbers in the top left hand corner of a calculator going clockwise.
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Montynut

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Re: CC swept area calulation
« Reply #4 on: April 29, 2013, 11:20:26 PM »
I assume you both forgot to divide by 1000 to convert to cc  ;D sorry couldn't help myself

Offline evo550

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Re: CC swept area calulation
« Reply #5 on: April 30, 2013, 10:47:55 PM »
Prefer the Pi method.....because the calculator has a symbol, don't need to remember any numbers ::)

Offline Tim754

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Re: CC swept area calulation
« Reply #6 on: May 01, 2013, 08:16:04 AM »
Feel free to add your own Manuals & Technical Doco's here............
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Offline mustanggrahame

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Re: CC swept area calulation
« Reply #7 on: May 01, 2013, 02:49:51 PM »


Did you know 1 kilogram = 1 litre of pure water at sea level ;)


And fits in a exactly in a 100mm cube

Cheers Grahame
RT1, DT1F, MX100A, TY80A, YZ80D, DT125E, CR125RE, 1982 KTM125RV, 1985 Can Am ASE, 1989 YZ250WR, 1991 YZ250WR

Offline bishboy

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Re: CC swept area calulation
« Reply #8 on: May 01, 2013, 03:02:42 PM »

Did you know 1 kilogram = 1 litre of pure water at sea level


And fits in a exactly in a 100mm cube

Which came first: the kilogram, the litre or the millimetre  ;D

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Offline mustanggrahame

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Re: CC swept area calulation
« Reply #9 on: May 01, 2013, 04:39:32 PM »
The metre came first. Then the gram which was the weight of water that fits into a 1cm cube at its most dense temperature (4 deg C). Then a thousand of these is a Litre.
Cheers, Grahame
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oldfart

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Re: CC swept area calulation
« Reply #10 on: May 01, 2013, 05:03:39 PM »
.7854 is how much of a cirlce fits into a square.

Offline Tomas

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Re: CC swept area calulation
« Reply #11 on: May 01, 2013, 06:10:29 PM »
RM 465

Pi x Radius squared x stroke

3.14 x (1/2 8.6cm bore x 1/2 8.6cm bore)x 8cm stoke

3.14 x (4.3cm x 4.3cm) x 8cm

3.14 x 18.49cm2 x 8cm = 464.46cm3= 464.46 cubic centimeters=0.46446 litre

1cm=10mm , 1000cm3= 1 litre


Offline OverTheHill

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Re: CC swept area calulation
« Reply #12 on: July 24, 2013, 07:45:29 PM »
gettin too technical for me but i'll save this page to refer to. Can use it now to work out my 70x70 stretched DT1 & 80x64 shrunk RT2, or for that matter my destroked overbored TF100 bucket racer [not run for years] using a crank [one side] from an RD200--52x46.5. Forgot i changed it to a 125 cylinder in the end so 56x46.5. But 'dumb me' not thinking--when i had my husky chainsaw apart, remember looking at the crank & measuring from centre of pin to centre of crank, looking at the verniers & thinking jeez how oversquare is 'that' [then i woke up].

Offline pancho

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Re: CC swept area calulation
« Reply #13 on: August 18, 2013, 03:25:44 PM »
Another interesting point, re CC.
 I was told by a person that should know that a Cubic Centimetre is not EXACTLY the same as a Millilitre, and that is one reason why in modern metrication Millilitre is used and not CC.
 The reason they are not identical is that the old method of getting an international standard representing one  CC was not as acurate as the modern methods of measurement, and that with modern measuring standards one Litre equals about 998 point something CC.
 
 I like trivia! (sometimes)
 
cheers pancho.
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Offline pancho

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Re: CC swept area calulation
« Reply #14 on: August 18, 2013, 03:27:13 PM »
 Anyone for a Trivia Thread?
dont follow me i'm probably off line!