ROTARY HISTORY 5
This column is Copyright 1997-2001 by Edwin Krampitz, Jr., unless indicated otherwise. Please ask for permission to reproduce.
*Reprinted on http://rotarywiki.com with consent of the author.
- Part 1:The Smallest Wankel Of Them All
- Part 2: The Smallest Production Aviation Wankel
- Part 3: Biggest of Them All
- Part 4: The Citroen Connection
- Part 5: Russian Rotaries
- Part 6: The Orphan Mazdas
- Part 7: The One that Won in '91
- Part 8: Chinese Experiments
ROTARY HISTORY 5: RUSSIAN ROTARIES
One of the most mysterious Wankel programs started behind the Iron Curtain during Cold War days: that of the Soviet/Russian automaker VAZ (now Avtovaz) of Togliattigrad. VAZ began building Fiats under license as Zhigulis 30 years ago; they have been sold as Ladas in the West.
The Russians expressed interest in the rotary in the '60s and sent technicians to NSU in Neckarsulm, West Germany, in 1974. VAZ began development in 1976 and in late 1980 came an announcement of a limited-edition 2-rotor Lada. The rotary was tested in races and rallies. Apparently 2- and 3-rotor engines with power ratings from 120 to 280 hp were produced in the '80s for use in the USSR. The most common seems to have been a 2-rotor rated up to 160 hp, used in KGB, militia (police), and military vehicles. Two of another 2-rotor engine, the 138-hp VAZ-413, were used in the Volga-2 Ekranoplan--one of the new ekranoplanes that has excited aviators.
The engine design bureau Aviadvigatel adapted the VAZ-4305 for aviation use as the D-200. As publicized in 1994, the prop version produced 217 hp and had a dry weight of 145 kg (320 lb) with installed dimensions of 990 mm length x 623 mm width x 690 mm height (39.0" x 24.5" x 27.2"). The D-200 was liquid-cooled with 2 spark plugs per rotor and used 91-95 octane gasoline; displacement and rotor dimensions have not been given. Two of these 2-rotor engines are used in the Mil Mi-34V 2- to 4-seat light multipurpose helicopter, replacing the Mi-34's standard radial engine and allowing a greater takeoff weight (max. 1,960 kg or 4,320 lb) and range (up to 980 km or 609 mi). The Mi-34 was developed for training and acrobatics, but the -34V, first shown in 1992, was planned for emergency and rescue missions. Why a rotary? Mil's general designer said, "We could not find a gas turbine small enough." [!] [Tracy's exclamation point.--EK]
Aviadvigatel had planned to replace many of the original VAZ components with "aircraft-type materials" and certify the D-200 by 1996 under US and European aviation regulations, but it isn't clear what has been happening since 1994. Avtovaz has had severe financial problems, and I suspect that Aviadvigatel has run into legal snags.
The D-200 may not be legally marketable in the West. I have found no evidence that VAZ or any other Soviet entity got a license from NSU/Wankel in the '70s. Despite mentions of rotary Ladas, no specs for any Soviet vehicle with a Wankel ever appeared in any of the standard reference sources such as World Cars. Believe me, I've looked. I have searched Russian books on vehicles and engines, including Russian-language Zhiguli repair manuals, at the huge Victor Kamkin bookstore in Maryland but have found absolutely no reference to VAZ's rotary efforts--though aside from licensing issues, the KGB and military uses may also have mandated keeping them secret. In fact, in such books published there in Russian or English, discussion of the Wankel engine and its principles is conspicuous by its total absence! To top it off, my correspondence to Avtovaz and Aviadvigatel in 1996 went unanswered, despite my getting a Russian trade representative involved.
Few technical details are therefore available about VAZ's rotaries. I suspect one reason is that they are probably direct copies of NSU's or Comotor's--as the rotor dimensions would likely reveal. Since most of the Wankel patents didn't expire until the '80s, Avtovaz would probably be liable for back license fees and penalties if it or Aviadvigatel tried to sell these rotaries in the West. It would be interesting to find out if licenser Wankel Rotary GmbH in Germany has pursued this issue with the Russians and kept the D-200 off the market. Can any of you provide any info?
POSTSCRIPT FOR INTERNET: Avtovaz has a Russian-language website describing its rotaries, though it is hard to find even through its normal website. Rotary versions of the front-drive Lada Samara have supposedly been available to the Russian public since 1997. The displacement per rotor is given as 654 cc, which is--surprise!--the same as that of the Mazda 13B. Indeed, a related website devoted to car sales gives the rotor dimensions. They are the same as the 13B. My Russian is lousy, but what I can make out of an interview transcript on the website seems to imply that VAZ got some sort of sublicense from Mazda. This wouldn't solve the licensing issues with Wankel Rotary itself, however. Can someone expert in Russian translate the interview? Variations are offered for aircraft. However, Jane's has recently dropped the Mil-34V from its list of production helicopters. General Motors has recently become involved with Avtovaz, though what will happen with the Russian automaker in the wake of the upheavals there is still open to question.
The USSR expressed an interest in the engine soon after production versions first became available, it appears. As early as 1968 came a book in Russian, "Rotoporshnevye dvigateli" ("Rotary-piston engines"). A technical congress dedicated to the Wankel was held in Tbilisi, Georgia, then part of the USSR, in 1981. Several Soviet-bloc technical articles on the Wankel appeared in various journals from the late 1960s through the 1970s, particularly in Poland. Military interest in the engine can be gauged by a two-volume translation of a Russian manual that the US Department of Defense translated and released in 1975. The manual's title is translated "Army vehicle engines" and it contains much about the Wankel. Copies can be ordered from either http://www.ntis.gov or http://www.sti.nasa.gov (Part I: order no. 75N75300 or AD-A003129; Part II: order no. 76N78318 or AD-A016229). These volumes are horribly expensive, though.
Aside from the overall level of technology in Soviet piston engines, the main reason the Russians were interested in the rotary was its ability to produce high power ratings from low-octane fuel. Soviet research on piston engines to combat knock because of their poor gas is discussed extensively in a recent SAE paper: no. 980117, "On the future of combustion in piston engines". When they learned of the capability of the Wankel to run happily on fuel that would blow a high-performance piston engine, they naturally became interested.
- Avtovaz http://www.vaz.ru/skbrpd
- The interview appears at http://www.vaz.ru/skbrpd/inter.htm
- See also http://7verst.carsale.ru/rpd ("RPD" is the Russian acronym for "rotary-piston engine")
- SAE paper available from http://www.sae.org