[Swede]

Thought you guys would like some pics... I produced this engine a few years ago from the Merritt Zimmerman design as published in SIC. The crankcase castings came from a fellow in Ohio, USA. I don't believe they are available anymore.

Some history - I ran this engine heavily on the bench, but have never flown it. After running it over a period of weeks, and happy to have it tuned up and running well, I tossed some anticorrosive oil into the cylinders and crankcase, and put it up on a shelf. Bad idea - the castor oil gummed badly over the last couple of years, While the pistons and crank were free, the tappets were locked, and the engine overall had a nasty, gummed, dusty coating, and in spots a touch of corrosion. Yuk. I decided to tear it down and clean it up.

The bore is .562" / 14.3mm, stroke roughly the same, 4-cylinders inline, glow ignition, poppet valve. The crankshaft is one piece, 2-piece connecting rods, and the split rods make use of shim bronze bearing surfaces formed in a custom die. The pistons are cast aluminum, with 2 rings per piston. Of course, I managed to break a ring trying to free said ring from its nest of gummed castor in the piston after tearing it down, and, unable to locate a spare, had to turn, split, and heat treat a new set of rings from C.I.

First pic: The engine viewed on the glow-plug / exhaust side. The exhaust stack is partially removed. The head is actually one piece of aluminum, machined in a fashion so as to appear to be 4 separate heads at first glance.

Second pic: The intake manifold is removed, revealing the intake ports, which branch via a "Y" inside the head to feed two cylinders for each port hole. The pushrods and rockers have been removed. The tapets are obvious at the bottom of the pic. Note the castor goo and overall sad state of the engine.