Avia M 337
# Avia M 337

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)
