Merritt Zimmerman produced his own castings to build (75) 1/6 scale Cirrus engines (glow ignition) between about 1980 and 1994. He sold many more castings in kit form for miniature engine builders during the same period. To differentiate his engines from those built by others, an oval shaped embossed emblem with the name “ZH Cirrus” was bonded to the crankcase identifying those engines completed by him. The oval emblem was not sold or included in any of the kits.
Eight of the seventy five engines were water-cooled. In the water-cooled engine the cylinders are mounted within an aluminum block so water can circulate through the block (around the cylinders) and up into the head. The head is machined in one piece with internal water passages to carry water from the cylinder block into the radiator. The engine is 7”-long, 3”-wide, and 5”-high.