MM21 - The Ross-Drive engine
|Year of construction||2002|
|Power piston||stroke||14 mm|
|Displacer piston||stroke||14 mm|
|Idle speed||600 rpm|
This engine was made after the pattern of MM05, but smaller by a third. By using accordingly smaller DURAN test tubes and matching sectional aluminium as well as PMMA for the chassis it was possible to build a small transparent and smoothly running engine, of which I made two, one being sold at Ebay.