I just removed both Pmags and installed an SDS CPI-2 ignition on my RV-9a with a carburated Lycoming O235-L2C engine. There were a few reasons for this conversion;
1. I was tired of sending the Pmags back to the factory every 100 hours to get the bearings replaced.
2. Brad mentioned that my engine may have an accessory case gear train resonance that was destroying the bearings. It's a brand new Lycoming engine and I had the same problem with my last engine. I have a light weight Catto composite prop which may have caused my new and old engine to not be able to smoothly spin the low rotational inertia prop. Brad at Emagair was very helpful, but he couldn't solve my problem.
3. I did not want to remove and inspect both ignitions for bearing tightness at every oil change.
4. I wanted an ignition that would not lose its reference to TDC, which happened to me on 3 occasions requiring emergency landings, and this pre-igniton destroyed the last engine.
5. I wanted to easily "set and forget" the programmable controller after modifying the RPM and MAP advance curves to suit my particular engine to reduce CHTs while remaining in the power curve.
6. I read reviews on VAF and after a few phone calls with SDS customers, all responses mentioned that customer service at SDS was outstanding.
I started using the conservative RPM-MAP advance curve that SDS recommends as a starting point for new installations. This curve fires at 23 deg BTDC and smoothly advances to 26 deg BTDC as a function of MP. Additionally, by pressing the LOP button the curve advances another 1-5 deg when cruising at higher altitudes. Previously I had to set the PMag canned timing curve about 10 deg ATDC rather than TDC to decrease CHTs. My #4 cylinder was always about 30-40 deg F hotter than the rest and baffle changes had a small effect on reducing temperature. I was always having to compensate for high CHTs as I slowly climbed to cruising altitude. My first hour long flight at cruising speed was uneventful. On my second flight I climbed at 1100 fpm from sea level to 5000 feet and the highest #4 CHT observed was 389 deg verses the previous 415 deg that I was used to dealing with. All CHTs and the range of temperatures were lower. I was expecting lower CHTs and was delighted to observe them.
I installed a complete Dynon HDX system last year. At the same time I installed an EarthX, 6.2ah, 2.2 lb, LiFePO4, backup battery which will provide about 45 minutes of reserve power for the ignition and essential avionics in case of an alternator, main battery, or main buss fault that requires turning off the MASTER or ALT switch. The backup battery is isolated by 2 large schottke diodes from the master buss. The BACKUP battery is normally switched ON during flight to keep it charged and to supply reserve power instantly in case the master voltage is interrupted.
I have been planning this conversion for about a year waiting for the CPI-2 to get released into production and to accumulate some flight time. I have called SDS on numerous occasions to ask questions and always received a knowledgeable response. Ross and Barry were very supportive after the purchase answering questions and mailing me parts usually with over night delivery. I followed the backup battery wiring diagram outlined in the Installation Manual, and I called Barry a few times for his guidance and advice. Here are a few photos of the installation showing the dual Hall Effect sensor triggered by magnets mounted in the flywheel and the the dual ECU mounted under the throttle quadrant which is out of the way but very easy to service. I bolted an aluminum block near the sensor wires as added protection from broken fan belt issues. Also, I was able to sell my used set of Pmags on VAF for close to the same amount that it cost to purchase the complete SDS-CPI-2 package.
I Just Converted From Pmags to a CPI-2 Ignition
Linear Mode
