This is a tech related question.

How do you calculate compression ratio?

I missed this class and the teacher briefed me on it but I forgot. He said something about TDC and BDC being subtracted?! He said you also have to count the surface area of the cylinder head combustion chambers when calculating.

I also need to know how to calculate displacement.

Its bore* Stroke and some other crap I don't remember.

 

static compression ratio = bore vol + chamber vol + deck height vol + piston vol + compressed gasket vol / chamber vol + deck height vol + piston vol + compressed gasket vol

displacement = pi/4 x bore^2 x stroke x #of cylinders

-Mindgame

 

Mindgame has it. He called displacement of one cylinder the "bore vol(ume)". It is also called "swept volume". "piston volume" is dish (+ number) or dome (- number).

Perhaps an understanding of what the compression ratio calculations mean would make it easier to understand the math.
Just memorizing a formula isn't going to help you much if engine building/design, etc. is in your future.

That being said:

Since displacement is so often calculated, here's an easy way to remember how to calculate it:

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


4.00 x 4.00 x 3.48 x 8 x .7854 = 349.85

or for one cylinder, 4.00 x 4.00 3.48 x .7854 = 43.73

The little square of numbers on your calculator starting in the upper left is 7854. (BTW, PI/4 is .7854 to about 5 decimal places).

No numbers to memorize; just understand what displacement is, and use your calculator.