If I measure the diameter of the piston on a gas engine will that give me the displacement? If so, isthere a chart that gives dimensions of various gas engines?

Dennis

NO.

The displacement is calculated by:

3.1416 x (radius of the piston)squared x length of stroke

All manufacturers list the displacement of the engines that they sell.

Ken

Thanks, I have several gas engines (1 is a weed wacker), several for airplanes, but I do not know size or manufacturer.

Thanks.

Place all your egines in a group and take a photo of them and have someone scan the photo. The you can show us what engines you have. Then we can help you figure out what you have. Thanks John