Formulas for calculating the bore and stroke of a diesel engine

[ruben]

Hello, I would like to know if there is a formula to calculate what diameter and stroke a diesel engine should have with a compression ratio of 20 to 1 or with a compression value of 25 bars.

 

[GreenTwin]

For an engine with a 1" diameter bore, the area of the top of the piston is pie-r-squared, so 0.785 sq.in.

Assuming a clearance of 1/16", then the volume at TDC would be 0.04906 cu.in.

For a 20:1 ratio, then the volume at BDC would be 0.98125 cu.in.

So 1.25" stroke.

My math is off somewhere.
Somebody help me.

.

 

[minh-thanh]

Compression ratio depends on 2 factors: r (radius) and h (length)
There are 2 types of h: h1 is the piston stroke and h2 is the combustion chamber
If you choose compression ratio 20:1
From there you calculate the ratio of h1 and h2
If you choose h1 stroke then you can calculate h2 and vice versa
Note - the combustion chamber is not cylindrical so to calculate its volume you have to measure everywhere or you can measure it by filling the combustion chamber with liquid and measuring the volume of liquid in the combustion chamber