The Hercules Engine News


| July/August 2001



20601 Old State Road Haubstadt, Indiana 47639Glennkarch@gte .net

In the design and construction of the double flywheel gas engines it was the accepted practice to keep the outer flywheel rim speed below 60 miles per hour. This was the safety factor considered necessary to prevent centrifugal force caused flywheel explosions.

You may wonder just how fast the rim speed is for the various Hercules built engines. Here is the formula for determining the outer flywheel rim speed. Take the flywheel diameter in inches times 3.14 and then divide by 12. This gives the rim circumference in feet. Multiply this by the RPM and then by 60. This gives the rim speed in feet per hour. Divide by 5280 to get the rim speed in miles per hour.

Shown below is a chart for the model E Economy engines.

HP

Flywheel Diameter in inches