Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Don´t know if you really ment Jan, or was calling out to Ben, who is the author here?

Anyway, yes you are correctly informed Tommy. The D16 is the smallest engine with the big bore cylinder.
("Big Bore" has 13mm bore & 16mm stroke, and "Small Bore" has 9mm bore & 16mm stroke).

This IS good news. I did some quick math and a 13mm piston has a little more than double the surface area over a 9mm piston, so if I am able to fit a D16 power unit on a Wilesco TE the power increase should be significant.