**Calculation Formulas**

**Stock Briggs & Stratton 5 hp. specifications:**

Deck height: 6.2835"

Rod length: 3.8750"

Compression height: 1.1900"

Rod bore (crank): 1.0010"

Rod bore (wrist pin): .4910"

Cylinder bore: 2.562"

Stroke: 2.4370

**Measuring Stroke**

Stroke is measured from the center line of the crank bearing journal to the center line of the rod journal multiplied by 2.

**Measuring Deck Height**

Deck height is measured from the center line of the crankshaft bore to the deck of the block.

**Measuring Compression Height**

Compression height is measured from the center line of the wrist pin bore to the top of the piston.

**Calculating Cubic Inch Displacement (cid)**

To calculate cubic inch displacement (cid):multiply bore x bore x stroke x .7854example: 2.562 x 2.562 x 2.437 x .7854 = 12.5633 cid

**Rod Length & Compression Height - Made Simple**

**Calculating Rod Length**

To calculate rod length:subtract deck height - (stroke divided by 2) - compression height.example: 6.2863 - (2.437 / 2) - 1.190 = 3.875 rod length

**Calculating Compression Height**

To calculate compression height:subtract deck height - (stroke divided by 2) - rod length.example: 6.2835 - (2.437 / 2) - 3.875 = 1.190 compression height