Working out CC of your bike

[Bike Bunker]

Just going to post a few Formulae that people may find interesting or even useful

Hope a few people maybe find this helpful or even interesting please pm if ive made any mistakes or feel free to post your own formulae

Thanks!



Working out the volume of a cylinder

Formula - H(height) x R(radius) x R(radius) x Pi(3.14)

Height is simply the height of the cylinder from BDC to TDC (Top Dead Centre and Bottom Dead Centre

Radius is found by measuring the diameter of the cylinder and simply halving it

Example:

ZXR400- Diameter or Bore =57mm Height or Stroke =39mm

PLEASE NOTE Engines are measured in CC3 (centimetres cubed) not MMC (millimetres cubed) so always convert to CM before starting any formula's

So take the formula input our measurements and get -

3.9 x 2.85 x 2.85 x 3.14 = 99.46135

The 2.85 comes from the diameter or bore which is 57mm converted to 5.7cm then divided by two as we need radius not diameter


Working out the CC of a engine

Formula - B x B x 0.7845 x S x N

B is Bore or Diameter of the cylinder
0.7845 is a constant and is not change regardless of bike or size.
S is stroke or height of cylinder
N is Number of cylinders

Example:

ZXR400

input the measurements into the formula;
5.7 x 5.7 x 0.7845 x 3.9 x 4

=398.0752776 cc simplified to 398cc or 400cc

Please note! an R1 is not 1000cc a zx6r is not 600cc and a aprilia rs 125 is not 125cc but it will be very close.

There are ways to work out your compression ratio but you need to find the clearance volume which is not as readily available for some bikes but for those who are lucky enough to be able to work it out or find it


Working out the compression ratio

Forumla - Pi x R x R x H=A then... A/CV

the ration is always too 1 so 6:1 or 7:1 it should never be 3:2 or 6:5
pi=3.14
R=Radius
H= Height
CV= clearance volume

Example

Please note in this case we convert everything to Cm and not MM
a bike with a 60mm bore 70mm cylinder height and clearance volume of 18 cc goes like;

3.12 x 3 3 x 7 =197.82/18=10.99 ration 10.99:1

(these figures was just pulled out of the sky and do not represent an actual bike)

P.s If you read all that bloody well done

[Ariel Badger]

So how do you calculate CV?
____________________
Bikers make great organ donors, get 115 on your licence today.

[Slacker24seve...]

As if you know what any of those big words mean.
____________________
Triumph Daytona 675 track bike + girlfriend's Honda Hornet 600
Selling a hack/winter bike for less than a grand? PM me.
Banger rallies are ace

[Timmeh]

To be honest, to work out CC, bore, stroke or compression ratios I just tend to read the manual.


____________________
GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
20:22:30 BLUEX5: i would love to be forced to undergo a**l plugging with different sizes
20:48:18 Temeluchus: comp you hunk of smouldering homos3x you

[keggyhander]

The CC is printed plain as day on the V5.

[JiveBunny]

You forgot a crucial point.

" Or simply look at the V5 document. "

[Nick_Giles]

[Bike Bunker]

.wrthsth

[Bike Bunker]

[JiveBunny]

[Bike Bunker]

[Slacker24seve...]

[Bike Bunker]

lmfao ive done alot to the bike since then and havnt updated , also the bike got so bad due to doing around 1+k miles everymonth no fail with no limits due to weather

[Ariel Badger]

[johnsmith222]

[wilz1234]

[Bike Bunker]

[Ariel Badger]

In his calculation he was trying to calculate CR so it is not known.
____________________
Bikers make great organ donors, get 115 on your licence today.

[Bike Bunker]

[The Shaggy D.A.]

[johnsmith222]

[Bike Bunker]

[The Shaggy D.A.]

Ah, a Mac user. 'Nuff said
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[Bike Bunker]

[Bike Bunker]