just had my 351 machined to .030 and was wondering what the new cubic inches were gonna be? Ive searched this forum for half an hour and cant seem to find the answer.

thnks

 

I was thinking it would be 393 CID. Use the formula:

Bore x Bore x stroke x # of cylinders x .7854 = engine displacment

4.030 x 4.030 x 3.850 x 8 x .7854 = 393 (rounded)

 

351 has 3.5 stroke. 3.030 X 3.030 X 3.5 X 8 X .7854 = 357 cu in

 

something's wrong with your formula
4 x 4 x 3.85 x 8 x.7854= 387 cu. in........................not 351??????

 

My post above should read 4.030 X 4.030 X 3.5 X 8 X .7854 = 357 cu in.

 

Common guys - volume of a cylinder is pie times radius squared times height.

4" bore has a radius of 2", pie is 3.1416.

So one cylinder = 3.1416 times 2" times 2" times 3.5 = 43.98 cu in

times 8 cylinders = 351.86 cu in.

A .030" over bore would change the radius to 2.015".

So one rebored cylinder would be 3.1416 times 2.015" time 2.015" times 3.5" stroke = 44.64 cu in. times 8 cylinders = 357.16 cu. in. total displacement.

 

Commonly called a 358.

 

Yup. 357 cu in.

 

I'm not much a motor guru, and my info was just based on a search from the internet and I guess I was wrong. So much for searching. My bad.

 

better to try and be wrong, than not to try...






at least with small stuff like this...