Just as topic says. I want to find out what displacement I will have in my motor with various bore sizes and can't seem to find out how to come up with the right number. Can anyone help.

 

Volume of a Cylinder*# of cylinders

So basically: V=pi*r^2*h
3.14*(bore/2)^2*stroke*4cylinders
Helps to put the whole thing in the same units, convert the bore and stroke to cm and you'll get an answer in CC.
Example: My D17
Bore: 75mm--> 7.5 cm
Stroke: 94.4mm--> 9.44 cm

3.14*(7.5/2)^2*9.44=416.8cc/cylinder
so 4 cylinders = 416.8*4=1667.34, Honda quotes displacement at 1668cc. If you drag out pi and your decimal places it'll be more exact.

 

Displacement = (Stroke * (Pi) * (Bore/2)^2)* Number of Cylinders

Keep units the same.
I think this is the formula you are looking for.

 

solid 1st post newbie

 

thanks guys i knew i was leaving something out

 

<<< tech newbie. let me re-illeterate that...

algebra
[(stroke) (Pi) (bore/2)^2] 4=volume/ displacement

1 convert units to cm
2 stroke(cm) times Pi(approx. 3.14)
3 bore(cm) divided by 2, squared
4 stroke and bored times 4
5 equals displacement in cubic centimeters(cc)

or

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PhillyrsxS &raquo;</TD></TR><TR><TD CLASS="quote">Displacement = (Stroke * (Pi) * (Bore/2)^2)* Number of Cylinders

Keep units the same.
I think this is the formula you are looking for.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AgentJam &raquo;</TD></TR><TR><TD CLASS="quote">solid 1st post newbie </TD></TR></TABLE>