I wanted to mention a recent mod to my 1951 C170A LYC 180HP that may interest some.
I recently had the electronic "LASAR ignition made by Unison in my airplane. The cost (gulp) was $3100 (everything included) with installation. STC and 337 for the C170 comes with it. If anyone is interested, they can do a web search for LASAR to find a number of references. The LASAR is a Lycoming thing. I am not sure about availability for Continental. I believe that there is a system called FADEC for Continentals.
The things that prompted my decision were:
Easy starting
Fuel economy
Redundency
Power improvement.
Here is what I found with my first 15 hours of stick time using the new system.
Starting is substantially easier...the ignition presets the timing to TDC when you turn the Master ON and set ignition to BOTH. The engine starts immediately, and runs very smoothly. No sputtering belching or farting around (my non-aviation terminology).
Also...the system comes with a "bushkit" option ($150) which allows you to hand prop if you want that option. One caution: when the engine starts, it starts IMMEDIATELY (usually second pull), so be sure you use proper technique.The best I could ever do BC (before conversion) for fuel was 9-9.5 GPH using 2350 over 2350 power settings for economy. I typically use these because my fuel capacity runs out quickly with the LYC. Over the first 15 hours of use (8hrs cross country, 6hrs short hops under 30 mins, and 1hr of T&G and airwork) I calculated the fuel burn to be 7.3 GPH overall, and 7.3 GPH during two seperate cross country segments. Traditional leaning procedures (25* lean of peak EGT) were used as I always have. Think about that. My range with reserves increased by 55 minutes!
As you might imagine...I was elated.The system includes two Slick mags that have sensors that feed info to the "brain box" mounted on the firewall. (The old mags won't work, so a good time to look at the system might be when you need to replace the old mags anyway.) There is an annunciator light for the panel to warn when the system defaults to the traditional mag system. You now have two fully operational ignition systems. The system also goes to default when you select each single mag for mag checks, and then blinks back on when you are done.
As for power...how do you know? I can't really gauge that effectively so I don't know. It seems logical however that a system where the spark timing of the engine throughout the full operation range is ALWAYS at precisely the optimum setting, should result in better power.
One other advantage that is only mentioned in most of the documentation I read, is that the engine REALLY runs smoothly. After a trip at cruise my (BC) engine would roughen noticeably when I reduced power to set up for my approach to landing. The new system allows me to reduce the power and and set up with absolutely none of the roughness in the engine I had before. The other place I noticed the effect of the system was smoothness on the ground after start and during taxi. I have a coffee cup holder next to the door post. It's highly technical you know...Nuff said.
I'm almost embarrassed at how this sounds like advertising, but I really like the system. The installation was unfortunately not as smooth. Time to fess up! We fired it up initally and the annunciator light stayed on all the time. Unison had us hook the system up to a laptop to read the fault codes for a resolution to the problem. Long story short, Unison, over the course of a week, sent us two new mags and finally a new "brain box" before the system worked correctly. Turns out it was the "brain box" itself that wasn't working properly! Once that was replaced, and ever since, the system has worked perfectly. I can't believe they don't have a way to bench test before shipping. Perhaps a little quality control program would help. Anyway, I don't have time to fix their problems, but this system really does work beautifully.
I just thought I would share my experience. Overall, despite the problems we experienced during the installation, it's well worth it. I'm not an expert, but can try to answer questions if anybody is interested.
Neil
