I did a search and couldnt find anything but i forgot what the math is to find engine displacement. I know a block bored .030 is 356cid but what is .040? its like bore x stroke or something.

 

In an over-bore, the bore diameter is increased by the stated amount. A Gen I 350 starts out with a 4.000" bore and 3.48" stroke.

The displacement formula is the formula for the volume of a cylinder - area of the base times height - times the number of cylinders. The area of a circle is pi (3.14159) times the square of the radius. If you square the diameter, you need to divide by 4 since r = d/2, and therefore (d/2)^2 is (d^2)/4. And, of course, there are 8 cylinders in a V8 engine.

So, (4.040"^2)/4 * 3.14159 * 3.48" * 8 = 356.879 or 357 cubic inches.

A .030"-over 350 comes out to 355.115 cubic inches, rounded off to 355.

A stock 350 comes out to 349.847 cubic inches, rounded up to 350.

 

For all intents and purposes, it's still a 350, it's just had some cleanup work on the bore. Don't fool yourself into thinking you're getting 7 extra cubes of power out of it or anything. I'd just refer to it as a 350, rather than a 357, that would just add confusion. (Althought saying you've got a three-fifty-seven does sound cool...)
Personally I call mine a 355, to show that it's not some 25yr old bone stock 180HP "350", but it's been bored out (and safe to assume other addons have been done ) so it actually puts out a lot more HP. Not due to the 5 extra cubes, but the fact those 5 extra cubes represent that i've had the engine open, and have changed other parts.
Just had to give my

 

It's a 350.

It will have about 356.88 cubic inches after the routine maintenance.

It'll still be a 350.

 

Give a guy the answer, he'll have a number.

Give a guy a formula, and he'll be able to figure it out for the rest of his life.

 

BORE x BORE x STROKE x NUMBER CYLINDERS x .786 = CUBIC INCHES (within 1ci)

 

Thanks guys thats exactly what i was looking for

 

your screen name confuses me....