Two Cycle Engine Port Timing Calculator

After entering the stroke and rod length, select either field to calculate. (1) enter the piston (port) height value and click "Calculate Duration" to get the open duration -or- (2) enter the open duration value and click "Calculate Height" to get the piston height. One field must have a value to calculate the other. Keep in mind measurement designations can be metric or US. Degrees are in both. Do not mix designations. You may view the source for more details of the formulae.