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Composite Oil Sump CAUTION:
Programmable Start-Up Firing Angle, as well as Run Mode Starting Delay from
earlier versions, are features NOT included with the initial release of series 113
ignitions. Those features are of interest to builders using composite oil sumps. If you
are currently using a composite sump, and need these features, contact E-MAG for
instructions, and the latest updates before installing your E-MAG system.
Background - Wasted spark systems avoid the weight, mechanical
complexity, and high altitude operating issues associated with traditional
ignition distributors. In a wasted spark system, plugs are fired in pairs at A)
the charged cylinder that’s ready to ignite, as well as B) the opposing cylinder
during the exhaust stroke. This second spark is not intended to ignite, hence
the name “wasted spark”. However, when restarting an engine shortly after
shut down (a hot start), it is possible for fuel vapor to accumulate in the intake
manifold. This vapor can be ignited by what is normally the “wasted” side of
the spark during valve overlap. [Valve overlap is when intake and exhaust
valves are momentarily open at the same time.] Even so, in the test cell
instance where this was observed, the event itself was rather unremarkable.
It was heard only as a hard “puff” prior to engine start. However, in that
instance, the intake manifold channeled this “puff” to the sump, which was
later measured as a 15 to 20 psi pulse. This pulse cracked the light weight
composite sump installed on the test cell engine. An identical replacement
sump did the same thing during a second hot start. When replaced with a
standard aluminum sump, the problem did not recur on any subsequent (hot
or cold) starts.
Operating Notes
Starting
- DO NOT use procedures suggested for other electronic ignitions (i.e.
power up the ignition after the prop is spinning.) To start the engine, simply turn ON
12 volt power to the ignition (presumably your main power switch), turn ON the
ignition p-lead (ground) switch, and then start the engine.
Electrical System Condition
- E-MAG’s power dip (kick-back) protection guards
against severe voltage drops that occur when the starter is first engaged. However,
in the event of a compromised electrical system (low battery, long cable runs,
corroded terminals, cold engine, etc) buss voltage may not rebound as the starter
speeds up (as is normal). A properly designed and functioning electrical system is
essential for the system to work properly. If buss voltage stays below safe levels, the
power dip safety circuit will do what it is supposed to do – not allow the ignition to fire.
Note: Your starter is likely the largest load on the electrical buss. In emergency
situations, hand prop starting will avoid the starter motor induced voltage drop. Do
