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High school question:

Why do I need to learn geometry? I’m not going to be a math teacher…..

Figuring out Cubic Inch Displacement.

Engine displacement is the volume of fuel that all pistons inside the cylinders of an internal combustion engine in

can draw in during an intake stroke. Commonly you’ll hear people talk about this in cubic centimeters (cc), litres (l),

or cubic inches (CID.) Engine displacement does not include the volume of the combustion chamber.

Now let’s think about our high school geometry. As you learned in high school math class, the volume of a cylinder

is 3.14 (also known as pi) x the radius squared x the height of the cylinder. Diameter is the distance across a circle

through its center point. In our case the bore size is the size of the circle. The radius is ½ the diameter. PI is the

ratio of the circumference to the diameter of a circle; approximately equal to 3.14(let’s not get too crazy on this,

3.14 is a constant which is always used as PI.) The height of the cylinder is how far up and down the piston travels,

and is known as the stroke. \

So let’s apply this to the Chevy 427:

Why do I need to learn geometry? I’m not going to be a math teacher…..

Figuring out Cubic Inch Displacement.

Engine displacement is the volume of fuel that all pistons inside the cylinders of an internal combustion engine in

can draw in during an intake stroke. Commonly you’ll hear people talk about this in cubic centimeters (cc), litres (l),

or cubic inches (CID.) Engine displacement does not include the volume of the combustion chamber.

Now let’s think about our high school geometry. As you learned in high school math class, the volume of a cylinder

is 3.14 (also known as pi) x the radius squared x the height of the cylinder. Diameter is the distance across a circle

through its center point. In our case the bore size is the size of the circle. The radius is ½ the diameter. PI is the

ratio of the circumference to the diameter of a circle; approximately equal to 3.14(let’s not get too crazy on this,

3.14 is a constant which is always used as PI.) The height of the cylinder is how far up and down the piston travels,

and is known as the stroke. \

So let’s apply this to the Chevy 427:

Bore size = 4.312 (this is the diameter) as I mentioned above the radius is ½ the diameter,

so the radius here = 4.312/2 or 2.156

PI is always = 3.14

Stroke = 3.65

Number of cylinders = 8

Applying the high school volume of a cylinder formula pi x radius squared x height we get:

3.14 x (2.156x2.156) x 3.65 x 8 = 426.4 CID

PI Radius squared height # cylinders = cubic inches

Now let’s try the Chevy 350

Bore size = 4.02(this is the diameter) as I mentioned above the radius is ½ the diameter, so the

radius here = 4.0/2 or 2.0

PI is always = 3.14

Stroke = 3.48

Number of cylinders = 8

Applying the high school volume of a cylinder formula pi x radius squared x height we get:

3.14 x (2.0 x 2.0) x 3.48 x 8 = 349.6704CID

PI Radius squared height # cylinders = cubic inches