And here's Charlie, explaining the theory to a 'non-believer'. Note that the "hot places" on the engines are of metal construction as described on the prior page!
Note the unique features of the center engine: A Scotch yoke displacer drive and dual connecting rod flywheel drive.
One needs to study Charlie's engines very carefully to fully appreciate their unique features. It is safe to say there are no other engines like these on the face of the earth!
Great workmanship Charlie. Thanks for bringing your engines to share with us.