Avia M 337
inverted six-cylinder air-cooled inline engine
The Avia M 337 (originally designated the Walter M337) is an inverted six-cylinder air-cooled inline engine. It was developed by the Czechoslovak company as a six-cylinder derivative of the four-cylinder M 332 engine, going into production in 1960. An unsupercharged version of the M 337 is designated as the LOM M137. Production transferred to Avia in 1964, and to Letecke Opravny Malesice (LOM) in 1992.
Variants
M 337A
Basic supercharged engine - not rated for aerobatics
M 337R
Modified for pusher installation
M 337AK
modified oil system for unlimited inverted flying. "Snap" aerobatics permitted.
M 337AK1
AK fitted with alternator instead of generator
M 337B
Increased max running speed (3000 rpm) - increased power - 175 kW (235 hp).
M 337BK
Aerobatic version of B.
M 337C
Increased compression ratio - 188 kW (252 hp)
M 137A
Unsupercharged version of M 337 130 kW (180 hp) take-off power. Aerobatics allowed.
M 137AZ
As M 137A, with filtered air feed
M 437
Gear ratio 0.7:1 180 kW (240 hp)
Applications
AeroVolga LA-8C
Falconar SAL Mustang
Let L-200 Morava
Zlín Z 526, Z 726
Zlín 142
Zlín Z 43
Specifications (M 337)
Data from Jane's All The World's Aircraft 1980-81
General characteristics
Type: 6-cylinder inverted air-cooled supercharged inline engine
Bore: 105 mm (4.13 in)
Stroke: 115mm (4.53 in)
Displacement: 5.97 L (364.3 in3)
Length: 1,410 mm (55.51 in)
Width: 472 mm (18.58 in)
Height: 628 mm (24.72
Dry weight: 148 kg (326.3 lb)
Components
Valvetrain: OHC two camshaft operated valves per cylinder, sodium filled exhaust valve
Supercharger: Centrifugal
Fuel system: Low-pressure fuel injection
Fuel type: Min 72-78 Octane
Oil system: Dry sump pressure feed system
Cooling system: Air-cooled
Performance
Power output: 157 kW (210 hp) at 2,750 rpm (take-off)
Power-to-weight ratio: 1.06 kW/kg (0.64 hp/lb)
References
Taylor, John W R, ed.
This brief starts where responsible research should: with the source description of “Avia M 337” as inverted six-cylinder air-cooled inline engine. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as inverted six-cylinder air-cooled inline engine. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Apr 15, 2026. The linked authority identifier is Q4828506. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1960, 1964, 1992 and 1980.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Avia M 337”, its source revision and the description used here.
- Expand the search: follow Avia M 337 primary sources, Avia M 337 archive and Avia research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Avia M 337”?
- Which institution is responsible for the underlying evidence?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Avia M 337” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.