1. Small Engine Displacement Calculations
Revised May 2007

2. Bottom Dead Center
Cylinder Head
3.375”
Stroke
3.25”
Bore

3. Top Dead Center
Cylinder Head
Combustion Chamber

4. Formula For A Successful Calculation
Cylinder Displacement= ∏xBore2 x stroke 4
3.375”
Stroke
3.25”
Bore

5. Formula For A Successful Calculation
Example:
Cylinder Displacement= 3.14 x x 3.375 4
3.375”
Stroke
3.25”
Bore

6. Formula For A Successful Calculation
Example:
Cylinder Displacement (in3)= 3.14 x x 3.375 4
3.14 x x 3.375 = 4
3.375”
Stroke
3.25”
Bore = 4

7. Formula For A Successful Calculation
Example:
Cylinder Displacement (in3)=
27.984 or
28 cubic inches
28 in3

8. Questions To See If You Learned It
Calculate the displacement of an engine with a bore of 8 inches and stroke of 7.375
What would be the displacement of an engine with 6 cylinders with the same bore and stroke mentioned above?
How much displacement per cylinder would a John Deere 4020 have if it has a 404 in3 engine?

9. Questions To See If You Learned It
If a grain bin is 30’ in diameter and 80’ tall, how many cubic feet would be in the grain bin?
If a bushel of grain occupies 1.25ft3, how many bushels would the above mentioned grain bin hold, if it was filled level to the top?

10. Algebra and Ag 28in3 = 3.14 x Bin2 x 3.375 in 4 4 x
112in = B2
= B2
= B

11. ANSWER
3.25 in