The Rare Vintage Russian MK12 S Competition Engine Story

Model	MK-12 S
Manufacturer	USSR (CCCP)
Distributed	USSR (CCCP)
Series / Serial No.	s / n
Year of manufacture	1956
Displacement	2.47 cc (0.151 cu. In.)
Bore	15 mm. (0.591 in.)
Stroke	14 mm. (0.551 in.)
Power class	Diesel
Time	2
Type of carburetor	Fixed (no speed control)
Admission	Rear rotary valve
Crankshaft on bronze	No
Fuel	Ether / Petroleum / Oil
Condition	Good
Comments	Russian Motor manufactured in small series, earlier model MK-12 B and V were found to be copies of Webra Mach I of the same displacement. Rear rotary valve, bearings and steel jacket with radial transfer. The piston is meehanite.

This engine was designed by the famous Russian modeller O.K. Gajewsji and was released to the public circa 1956.

The engine was used for competition freeflight and control line team racing. The following picture shows the individual parts.

The Russians called this engine the Motop MK12 c (cyrillic, 'c' is 's' in English).

The engine was received complete with a first place competition medal, a wooden propeller and a length of fuel tubing

Engine Box

Items found in the box.

The swallow logo is also stamped on one of the mounting lugs

There are two versions of the competition engine: the MK12S featured here and the more powerful MK12K shown below. 

The main differences are: a thicker prop-driver; a different spray-bar assembly, and a red ring around the cooling jacket inscribed with the name MK12-K

Specification sheet from a book on Russian engines written entirely in Russian

Translation

This same publication claims a maximum power output of 0.357 horsepower for the MK-K engine  

OK! Enough of this technical discussion; its time for a test run to see how she will perform.

Cold start with a 40/30/30 fuel mixture of kerosene, ether, and castor oil respectively. The propeller is a 8X6 Master AirScrew.