I'm just doing some cubic inch calculating and want to make sure my math is correct..

Radius x radius x pi. So for a 4" bore radius is 2"
X stroke x 8 cylinders

I know that's pretty basic without knowing the head chamber volumes but that should be accurate?

 

Hi 76etc,

Here's the formula :

pi/4 * bore * bore * stroke * number of cylinders = Cubic Inch

You might find these useful later :

<table border="0" cellpadding="0" cellspacing="0" width="460"><colgroup><col style="mso-width-source:userset;mso-width-alt:16822;width:345pt" width="460"> </colgroup><tbody><tr style="mso-height-source:userset;height:15.0pt" height="20"> <td class="xl63" style="height:15.0pt;width:345pt" height="20" width="460">Cylinder volume = 0.7853982 x bore squared x stroke</td> </tr> <tr style="height:15.0pt" height="20"> <td class="xl63" style="height:15.0pt" height="20">Deck Clearance volume = 0.7853982 x bore squared x deck height</td> </tr> <tr style="height:15.0pt" height="20"> <td class="xl63" style="height:15.0pt" height="20">Piston dome or dish in cubic inches = cc's x 0.0610237</td> </tr> <tr style="height:15.0pt" height="20"> <td class="xl63" style="height:15.0pt" height="20">Head-gasket volume = 0.7853982 x gasket bore squared x compressed thickness</td> </tr> <tr style="height:15.0pt" height="20"> <td class="xl63" style="height:15.0pt" height="20">Chamber volume in inches = cc's x 0.0610237</td> </tr> <tr style="height:15.0pt" height="20"> <td class="xl64" style="height:15.0pt" height="20">Dish volume = dish bore squared x dish height x .7853982</td> </tr> <tr style="height:15.0pt" height="20"> <td class="xl63" style="height:15.0pt" height="20">1 Cubic Inch = 16.387064 Cubic Centimeters</td> </tr> </tbody></table>

 

What is that?

Just take

Radius x radius x pi. x stroke x 8 cylinders

2*2= 4*PI*3.5= 43.98*8= 351.8CID

 

Another easy formula for displacement is:
Bore X Bore X stroke X # of cylinders X .7854 = displacement

Another trick that works on a 8 cylinder with a 4.0" Bore, take the stroke and add 2
a 302 has a 4".0 and a 3.00" stroke take the 3.00 stroke and add 2 302