SECTION 2 LYCOMING OPERATOR’S MANUAL
SPECIFICATIONS IO-320 SERIES
SPECIFICATIONS
IO-320-A1A, -A2A, -E1A, -E1B, -E2A, -E2B
FAA Type Certificate ................................................................................................................................. 1E12
Rated horsepower...........................................................................................................................................150
Rated speed, RPM........................................................................................................................................2700
Bore, inches.................................................................................................................................................5.125
Stroke, inches..............................................................................................................................................3.875
Displacement, cubic inches.........................................................................................................................319.8
Compression ratio ....................................................................................................................................... 7.0:1
Firing order ............................................................................................................................................. 1-3-2-4
Spark occurs, degrees BTC..............................................................................................................................25
Valve rocker clearance (hydraulic tappets collapsed) ......................................................................... .028-.080
Propeller drive ratio ....................................................................................................................................... 1:1
Propeller drive rotation (viewed from rear) ........................................................................................Clockwise
IO-320-B1A, -B1B, -B1C, -B1D, -B2A, -D1A, -D1B; AIO-320; LIO-320
FAA Type Certificate ................................................................................................................................. 1E12
Rated horsepower...........................................................................................................................................160
Rated speed, RPM........................................................................................................................................2700
Bore, inches.................................................................................................................................................5.125
Stroke, inches..............................................................................................................................................3.875
Displacement, cubic inches.........................................................................................................................319.8
Compression ratio ....................................................................................................................................... 8.5:1
Firing order* ........................................................................................................................................... 1-3-2-4
Spark occurs, degrees BTC..............................................................................................................................25
Valve rocker clearance (hydraulic tappets collapsed) ......................................................................... .028-.080
Propeller drive ratio ....................................................................................................................................... 1:1
Propeller drive rotation
All but LIO-320 Series......................................................................................................................Clockwise
LIO-320 Series......................................................................................................................Counterclockwise
IO-320-C1A, -C1B
FAA Type Certificate ................................................................................................................................. 1E12
Rated horsepower...........................................................................................................................................160
Rated speed, RPM........................................................................................................................................2700
Bore, inches.................................................................................................................................................5.125
Stroke, inches..............................................................................................................................................4.375
Displacement, cubic inches.........................................................................................................................319.8
Compression ratio ....................................................................................................................................... 8.5:1
Firing order* ........................................................................................................................................... 1-3-2-4
Spark occurs, degrees BTC..............................................................................................................................25
Valve rocker clearance (hydraulic tappets collapsed) ......................................................................... .028-.080
Propeller drive ratio ....................................................................................................................................... 1:1
Propeller drive rotation
All but LIO-320 Series......................................................................................................................Clockwise
LIO-320 Series......................................................................................................................Counterclockwise
* - LIO-320 Series Only
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