How to cal. cubic inches?

[Cornfield creations]

I wanted to know how to calculate cubic inches on a small block.

I have a 327, bored .060 over, 9:1 aluminum flat top pistons and double hump heads, 64cc chamber.

 

[4X4HIGH]

Bore x Bore x Stroke x .7854 X the amount of cylinders (8 in this case).

A 327 bored .060" is now a 336.6

 

[goldwing2000]

That's a weird formula. It seems to work but it's weird.

I've always used the area of the bore (pi x the radius²)xthe strokexthe number of cylinders.

Where do you get that .7854 constant from?

 

[MTMike]

That's a weird formula. It seems to work but it's weird.

I've always used the area of the bore (pi x the radius²)xthe strokexthe number of cylinders.

Where do you get that .7854 constant from?

It appears to be based off of the square root of 1/2 of the bore/pi (hence the double multiplication of the bore)

 

[goldwing2000]

It appears to be based off of the square root of 1/2 of the bore/pi (hence the double multiplication of the bore)

Man, that's complicated.

I'll stick with regular geometry.

 

[MTMike]

Man, that's complicated.

I'll stick with regular geometry.

Thats about the extent of my knowlege of it - If you want more detailed info than that I can ask my 1-semester-away-from-a-math-degree wife

 

[goldwing2000]

Thats about the extent of my knowlege of it - If you want more detailed info than that I can ask my 1-semester-away-from-a-math-degree wife

Nah. I'm good with old "pi r squared". That's the way I was taught back in 1989, so that's what I'm going to use!

 

[boz42]

i always used the .7854 constant, i learned it that way 15 yrs ago

 

[BigBen]

area is pi * radius^2
If you use bore, you are using the diameter.
area is now pi* (diameter/2)^2
Factor out the denominator and you have:
pi*diameter^2/4
or, diameter^2 * (pi/4)
pi/4 is........................................



.7854



brought to you by the 'magic of math'!

-Ben

 

[MTMike]

area is pi * radius^2
If you use bore, you are using the diameter.
area is now pi* (diameter/2)^2
Factor out the denominator and you have:
pi*diameter^2/4
or, diameter^2 * (pi/4)
pi/4 is........................................



.7854



brought to you by the 'magic of math'!

-Ben

I knew it was something like that but havn't done math like that since 1998 so I couldn't work out the equation.....

 

[pauly383]

I always forget the formulas , but I always remember every .030 is around 5 cubes for an 8 cylinder ( round up for advertising )