Small Engine Displacement Calculations

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Small Engine Displacement Calculations

• Stacey Beacham

Revised May 2007
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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
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3.375 Stroke
3.25
Bore
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Formula For A Successful Calculation
Example
Cylinder Displacement 3.14 x 3.252 x 3.375
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3.375 Stroke
3.25
Bore
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Formula For A Successful Calculation
Example
Cylinder Displacement (in3) 3.14 x 3.252 x 3.375
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3.14 x 10.5625 x 3.375

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3.375 Stroke
3.25
Bore
111.93609

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Formula For A Successful Calculation
Example
Cylinder Displacement (in3)
27.984
or
28 cubic inches
28 in3
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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?

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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?

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Algebra and Ag
28in3 3.14 x Bin2 x 3.375 in
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28in3 3.14 x Bin2 x 3.375 in
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x
112in B2
10.5975
10.56853 B2
10.56853 B
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ANSWER
3.25 in