jliltd
Active Member
I opted to try a new SureFly SIM4N non-impulse ignition module in place of the right Slick magneto in my 200hp A-1B. It was time for a 500 hour inspection on the mags and I have been having starting problems in the injected angle valve engine as of late (both hot and cold). And I have a lot of experience hot starting Bendix RSA equipped Lycomings.
I chose the non-impulse model SIM4N because I figured that it ,combined with the traditional impulse coupled left magneto during start, would give me all the starting ignition fire available. Since I was replacing the right magneto I accessed the ignition switch and removed the jumper that traditionally grounds the right mag when the key is in the start position. Leaving this jumper in place would mean the SIM (SureFly Ignition Module) would not fire for start.
The SureFly installation requires the new SIM be directly hot wired to the battery with 10 amp circuit protection. This bypasses the master switch and ship's electrical bus so that the SIM always has power, similar to a magneto still working no matter any electrical bus condition.
Since the Husky has the battery and both solenoids under the rear baggage compartment I had to install the new breaker aft in that location. I routed the new ignition wire from the breaker forward through the firewall to the SIM per the instructions.
I opted to set up the SIM with fixed timing matching the engine dataplate; 20 degrees BTDC. There is no practical or performance reason to attach the manifold pressure line to the SIM to engage it's advance timing curve function. It is much more conservative, especially on the angle valve engine, to stick to fixed timing. The RV and Glasair guys all rant and rave about such things as timing advance curves but they are in a different mission profile and altitude regime than a bush plane like a Husky.
After removing the mag gear from the Slick I installed it on the new SIM. In order to time the magneto I attached a 9V transistor battery to the SIM timing terminal with a pair of alligator test leads and turned the mag gear to just at the point where the led light on the unit went out. With the engine positioned with #1 cylinder on TDC we stabbed the mag and then verified the timing LED would go out at top dead center cylinder.
The aircraft now starts in half a blade cold and one blade hot. And it has been hot, baby. 105 degrees F on the ramp today when testing. I have 4 flights in on the system and am very happy. This was all done for ease of starting and smooth cruising. Not for any increase in economy or the like. I will leave Thursday for Oshkosh and my trip will be a perfect opportunity to really shake down the new ignition.
Jim
I chose the non-impulse model SIM4N because I figured that it ,combined with the traditional impulse coupled left magneto during start, would give me all the starting ignition fire available. Since I was replacing the right magneto I accessed the ignition switch and removed the jumper that traditionally grounds the right mag when the key is in the start position. Leaving this jumper in place would mean the SIM (SureFly Ignition Module) would not fire for start.
The SureFly installation requires the new SIM be directly hot wired to the battery with 10 amp circuit protection. This bypasses the master switch and ship's electrical bus so that the SIM always has power, similar to a magneto still working no matter any electrical bus condition.
Since the Husky has the battery and both solenoids under the rear baggage compartment I had to install the new breaker aft in that location. I routed the new ignition wire from the breaker forward through the firewall to the SIM per the instructions.
I opted to set up the SIM with fixed timing matching the engine dataplate; 20 degrees BTDC. There is no practical or performance reason to attach the manifold pressure line to the SIM to engage it's advance timing curve function. It is much more conservative, especially on the angle valve engine, to stick to fixed timing. The RV and Glasair guys all rant and rave about such things as timing advance curves but they are in a different mission profile and altitude regime than a bush plane like a Husky.
After removing the mag gear from the Slick I installed it on the new SIM. In order to time the magneto I attached a 9V transistor battery to the SIM timing terminal with a pair of alligator test leads and turned the mag gear to just at the point where the led light on the unit went out. With the engine positioned with #1 cylinder on TDC we stabbed the mag and then verified the timing LED would go out at top dead center cylinder.
The aircraft now starts in half a blade cold and one blade hot. And it has been hot, baby. 105 degrees F on the ramp today when testing. I have 4 flights in on the system and am very happy. This was all done for ease of starting and smooth cruising. Not for any increase in economy or the like. I will leave Thursday for Oshkosh and my trip will be a perfect opportunity to really shake down the new ignition.
Jim
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