L-1318
Unison Industries
530 Blackhawk Park Avenue
Rockford, Illinois, U.S.A. 61104
©2006 Unison Industries, Inc.
ISSUED
MO DAY YR
11 01 89
REVISED
MO DAY YR
01 31 06
PAGE NO. REVISION
G
0.1.1 A COMPLETE OFFERING
Slick Ignition Components are available in the following configurations:
- Engine Upgrade Kits: Cost saving kits include two magnetos, a complete harness, a complete set of spark
plugs and all mounting hardware.
- Single magnetos: Timing pins are included for easy installation.
- Custom Fit Harnesses: Both complete and half harnesses are available.
- Custom Fit Dual Harnesses: For TCM/Bendix dual magnetos.
- Universal Harness Kits: For those who prefer to build up their own assemblies.
- Individual Leads: For single lead replacement.
- Service Parts: For all Slick magnetos and harnesses.
0.2 AIRCRAFT MAGNETOS
Unison Industries utilizes a descriptive part numbering system for both Slick magnetos and Slick ignition
upgrade kits.
Magneto Part Numbering
Current production magnetos have four digits in the part number. The first two digits indicate the series:
43xx - 4300 Series for 4-cylinder engines
63xx - 6300 Series for 6-cylinder engines
The last two numbers indicate the model number.
0.2.2 ROTATION, LAG ANGLE AND RETARD ANGLE
Rotation
Rotation specifies the direction in which the magneto rotor shaft turns when viewed from the mounting end
of the magneto. Left-Hand Rotation is counterclock-wise when viewed from the magneto-mounting end:
Right-Hand Rotation is clockwise when viewed from the magneto-mounting end.
Important:
Check the data
plate on the magneto being replaced for the shaft rotation. Replace with a magneto having the same rotation.
Lag Angle - Impulse Coupled Magnetos
The impulse coupling is a mechanical device that assists in engine starting. At low cranking speed, the
magneto impulse coupling retards the magneto ignition timing until the engine crankshaft is at its proper
position for starting. The lag angle, noted on the magneto data plate, is the impulse coupling’s retard angle
measured in degrees. After engine start, the impulse coupling disengages and returns the magneto to normal
engine timing.
Lag Angle - Retard Breaker Magnetos
The retard breaker assembly is an electrical device, powered by the aircraft battery, used to aid in starting
the engine. At low cranking speed, the retard breaker retards the magneto ignition timing until the engine
crankshaft is at its proper position for starting. The lag angle, noted on the magneto data plate, is the retard
breaker’s retard angle measured in degrees. When the engine starter disengages, the retard breaker
assembly is also disengaged and the magneto returns to normal engine timing.
0.2.3 MAGNETO INSTALLATION ORIENTATION - RIGHT AND LEFT
In most cases, right and left magneto positions are referenced from the rear of the engine, i.e., from the pilot’s
perspective. Reference engine and/or airframe manufacturer’s literature.
0-2
