how to figure displacement after boring?

Did a quick search and didnt find anything. I have a 52 ford flathead with stock stroke but it was bored 40 over. It cant be much more than the stock 239. Any math wizards out there?

 

Cubic inches = 3.1416 x Radius squared (1/2 dia.) x stroke x # cyl.(8). The bore should be in decmials like 3.375" etc. hope this helps.

 

0.7854 x bore x bore = x stroke x number of cylinders = .............

Example: 350 Chevy

0.7854 x 4.00" bore x 4.00" bore = 12.5664 x 3.480 stroke = 43.731072 x 8 cylinders = 349.84857 or your basic 350 Chevy displacement.

 

im getting 245 ci

 

Thanks guys!!! Good info.

 

Very, very basis rule of thumb (and we all have the same size thumb, right?) is that you'll get 10 ci for 0.060" overbore. So your 0.040 gives about 6 ci. Like I said, very loose guide. Small bore engine get a bit less, big bores a bit more.

 

bore x stroke x 3.1416 x # of cylinders = cubic inches

 

hot rust, you need to review your geometry. 408 AA/D has it correct above.

bore x bore x stroke x number of cylinders x .7854 = displacement

If your measurements are in inches, you get cubic inches; if you want metric measure (cc), use cm or use mm and divide result by 1000.