The MARZ 2.5 cc diesel was a product of the late Communist period in Russia, being produced in quite large numbers from the mid 1970's until the end of the Communist era in 1989. It seems to have been a "consumer grade" replacement for the earlier RITM (Rhythm) 2.5 cc team race diesel which had been the standard Russian "clubman" team race engine since 1962. Like a number of other similar products, it was widely distributed through the Russian school system to encourage interest in technical subjects among Russian youth.
The MARZ was manufactured at a facility in Moscow which was primarily dedicated to the servicing of military helicopters - the model engines were made in batches during periods when activity on the helicopter front was low. The standard of production was generally quite good, although there was a great deal of inconsistency in the fitting and assembly of the engines, mainly with respect to the matching of the ports. That said, a good example runs really well, although the crankshafts have shown themselves to be somewhat prone to failure under high-stress operational conditions.
After manufacture ended in Russia, a large batch of the engines were somehow transferred to Australia, where some of them were converted to glow-plug operation. In this form, they were far less powerful than the diesel models. An exhaust collector ring was also developed, although this reduced power output considerably along with the noise level. Some engines had plain un-anodized cooling jackets, but most were black.
The remaining MARZ stocks were eventually acquired by Ed Carlson of Carlson Engine Imports in Arizona. Ed was still selling off his remaining stocks last time I checked..........
Towards the end of production, the same facility also manufactured a 2.5 cc Schnuerle-ported ABC glow-plug unit which was expressly intended for use in FAI control line combat. This was known as the Typhoon 2.5K model. With its twin angled rear exhaust stacks, it was quite a striking-looking engine which ran well. It was reportedly made in far smaller quantities than the MARZ diesel, and relatively few examples left Russia until many years after production had ceased.
The full story of the MARZ 2.5D may be found on Ron Chernich's "Model Engine News" (MEN) web-site.