Above photo by Lou Nathanson at 24,000′, looking down at the peak of Mt McKinley (dark ridge at bottom of frame). Glasair Sportsman with one magneto and one E-MAG . . . “Not a hiccup.”
Tips and Tricks
In our Installation and Operating Guide, we try to keep necessary and helpful information from becoming “too much” information. As a result, there are undocumented features and techniques left out of the manual. Some of these items can be very helpful – when and if needed.
On this page, we will indulge a little extra “print” to expand on some of these items. Not all comments will apply to all installations, to all ignitions, or to all firmware versions. This section assumes you already have a basic working knowledge of the system. We also DO NOT list the many safety precautions/procedures/standards that may be required – proceed with caution. Tips and tricks will be added on an ongoing basis so keep watching. If you have a tip – send it to us and we can pass it along.
Alternate for “blowing” in the MAP tube (Quick-Set timing): The manual calls for blowing in the MAP tube (0.5″ psi for one second) for each of the (two) Quick-Set timing commands. If disconnecting the MAP tube is inconvenient, you can pinch (or fold) the MAP tube approximately 1″ away from the nipple at the ignition, and then pinch the trapped air chamber to simulate the “blow”. This can make our simple timing routine – even simpler.
A shiny wrench held at the proper angle can help if you are needing to wiggle the prop, and at the same time, look for the green or red LED on the back of the ignition. Some have installed reflective/polished metal tape (or polish a strategic spot on the firewall itself) to accomplish the same thing. Fiber optic tube can provide a flexible line of sight directly to the cockpit, or a short piece can re-orient the LED beam so its visible thru the oil filler door. Also, see below “Alternate TDC signal” (first bullet) to see how you can add an audible signal to supplement the “GREEN” LED function.
In most “recent” versions of the firmware, the ignition will signal TDC (concurrent with the green LED) by sending continuous tach voltage to the tach terminal (#6 on the green plug). This has two nifty uses.
- You can connect a small piezo buzzer to terminal #6 (tach) and to terminal #1 (ground) and mount a buzzer at a remote location (by the prop or in the cockpit). This provides a convenient (audible) TDC signal (green LED equivalent) without a sightline to the back of the ignition. You can check ignition timing without removing the cowl – you can “hear” the TDC (green LED) signal. The LED function will be unchanged (still works).
- The other use is testing your tach output. Previously, confirming our tach circuit, or measuring the tach output voltage (5 volt vs. 12 volt) required an oscilloscope. Now, with the ignition 1) in setup mode and 2) positioned at TDC (confirmed by a continuous green LED), you can check the tach circuit output with a simple volt meter. Note: You may need to disconnect other tach leads from the plug to make sure you are testing the ignition output (alone), and eliminate interference from the tach wire or the tach instrument. If your firmware version doesn’t have this feature, it will register nothing (no voltage).
Reminder – We have a Troubleshooting Tips guide on our Downloads page.
You have seen our booth demonstration at airs shows where we power the ignition with a 9-volt battery in order to show:
- How Quick-Set timing (blow-in-the-tube) works.
- How little current the ignition draws. The ignition will make sparks powered only by the small battery. We explain that emergency prop-starting could be accomplished in the same way.
Earlier this year a customer relayed a story of how this routine was put to the test. His group had flown to an out of the way spot (small airport) for an overnighter. In the morning, they discovered one of the planes had left the master switch on and totally drained the battery. Remembering our demonstration, they scrounged a 9 volt battery, wired it in, and prop started the engine.
Bottom Line – If you’re going to keep a flashlight in your flight-kit anyway, you might as well get one that uses 9-volt batteries. Remember, if starting this way you’ll want to make sure the 9-volt supply is isolated and powering the ignition ONLY (not back feeding the rest of the buss). You might keep the master switch OFF, or pull the ignition breakers, or make certain everything else on the buss is OFF while you are prop starting the engine. Once the engine is running, give it some time to charge the battery so you’ll have power from the craft if needed (you still want the ignition to have two sources of electrical power).
(NOTE: This issue has been addressed in firmware V40, and after, by adding a 4 degree startup firing lag.)
Lightweight low mass props, by their nature, have less flywheel effect on the engine. This allows the engine to decelerate much quicker as the starter motor pulls against each compression stroke, and as the engine approaches TDC – where the plugs fire for startup. Under the right conditions, the combination of low mass prop, weak or undersized battery, corroded terminals, cold engine, long cable runs, tired starter (or any combination) can cause the engine to come to a (virtual) stop by the time it reaches TDC. At this point there is a 50/50 chance the engine will move forward or backward (a so-called kick-back) when the plugs fire. While the ignition may be performing as designed, the results are the same. Fortunately, there is an easy defense.
Simply re-time the ignition with the engine parked two or three degrees “AFTER” TDC (instead of “AT” TDC as you normally would). AFTER TDC means (from the TDC position) rotate the prop in the normal direction of travel to your revised target timing mark. Note: This will also slightly retard the operating advance range, but this small amount is not likely to be noticeable for most flyers. If desired, the shift can be nulled with the EICAD interface.
Some styles of ground (110 volt) chargers will hammer the battery with pulses as part of their normal charge cycle. Such hammering is not a typical buss state and can cause problems for the ignition if it is powered ON during such a charge. KEEP IGNITIONS POWERED OFF WHILE (GROUND) CHARGING.
We have learned that certain types of permanent magnet alternators, alone or in conjunction with small light-weight buss batteries, can induce significant voltage spikes to the electrical buss. These spikes are capable of overdriving (heating to the point of failure) the power regulation section of our ignition. E-MAG customers need to verify the electrical buss supplying power to the ignitions is properly regulated and filtered. If using a permanent magnet (“PM”) alternator, a properly designed crowbar circuit should be considered MANDATORY. Customers should also be aware that many of the new non-traditional (non lead-acid) batteries (gel-cell, lithium-ion, lithium-iron phosphate, etc) frequently have different charging profiles. Anytime a battery is unable to absorb/buffer output from the alternator, the excess will likely go out to all the appliances on the buss, including our ignition.
Credit to customer Howard Kanner for working out a tach signal solution for Vision Microsystems engine monitor… “It took me a couple of months to settle on a solution for tach signal, but my tach is stable now in the many flights since my last test iteration. I’ve settled on a 250 ohm resistor across the tach input to the VMS box.” Thanks again Howard.
E-MAGs require very little maintenance. The system has very few mechanical “wear” parts. Even so, there are a few items you can do at annual to check the condition of the ignition – none of which require disassembly of the unit itself. The Installation and Operating Guide Maintenance section references the following areas you can inspect.
- Check E-MAG web site for most recent Service Notes and verify equipment is current.
- Ignitions come with a (one-time trigger) thermal sticker that will trip (turn from light ash color to gray or gray/black) if case temperatures exceed 200 degrees (F). If tripped, review blast cooling and/or other ventilation issues that affect ignition cooling. Keep ignition temperatures below 200 degrees.
- Ohm check plug wires (see “Ohm Check” above), and examine spark plugs for signs of unusual wear or build-up. Gap plugs per instructions above. Replace auto style plugs with new ones after 100 to 125 hours. When reinstalling auto style plugs with auto plug adapters, review plug/adapter installation guidelines in the manual.
- Remove ignition and examine shaft and drive gear condition. Note: Ignition disassembly is not necessary (and if done may void your warranty). Look for excessive play (lateral and axial). Shaft rotation should be free, with no catching, flat spots, or grinding. The shaft on “P” models (with internal alternator) will have a push-pull rippling effect as the shaft turns and the permanent magnets pass the rotor poles. This is normal and expected. If a P model ignition does not have this magnetic ripple, the unit requires additional (shop) service.
- Examine control plug and coil plug connections – tighten wire cage-clamp to 4-5 inch pounds. Verify there are no stray wire strands or loose wires. Verify all control wires use the Adel clamp strain relief.
- Reinstall the ignition, re-time, and verify proper operation. For P models, re-verify minimum operating speeds when running on internal power (see Minimum Operating Speed test in the manual.)
Beyond the RED and GREEN LED signals described in the manual for setting timing, other LED signals are as follows:
- Sensor Magnet Range Check – Every time the ignition powers up, the ignition first performs a self-test to verify the sensor magnet is within an acceptable range. If the Range Check passes, the ignition proceeds with initialization (no LED signal). If the Range Check fails, it will proceed no further and will signal an alert with a pulsing (approx 1 every quarter sec) YELLOW LED. From the operators perspective it will appear as a non-operative ignition. The flashing YELLOW will continue until the infraction clears or the unit is powered OFF. No record of the alert remains after power OFF.
- Successful Start UP – Next, the ignition will signal a successful start up with an LED color burst. The color burst will occur immediately after power up and will appear as a quick pulse of RED and a quick pulse of GREEN – any overlap of the two may appear as YELLOW. At this point the ignition is active and ready for service. The color burst is very brief. To see it you’ll need to be staring at the LED when you power up.
- If the p-lead was grounded PRIOR to power up and REMAINS grounded, the ignition will light the LED steady RED or steady GREEN (after the step 2 color burst). The color will depend on engine position relative to the ignition index. If the p-lead was not grounded, the LED will go dark after the color burst. Setting timing and the rules for setup mode are discussed in more detail in the manual.
- Should the ignition later detect a sensor magnet position infraction, after a successful start up, it will NOT interrupt ignition operation. It will continue to fire plugs and perform all operational tasks. But it will signal the infraction by lighting the LED steady YELLOW (no pulsing). The yellow signal will remain until the condition clears or the ignition is powered OFF. No record of the infraction remains after power OFF. The next time the ignition is powered ON the process starts over again with step 1.