ilya1502 wrote:AKar wrote:these dual magneto thingies on them
What exactly you mean?
As already clarified by others, dual magneto is a single unit having two distributors and ignition circuits, but turned by a single drive. It saves small amounts of space on the accessories. Nothing much, really. Google 'Bendix D-3000' to see some pics. One sometimes hears some bad things about them, I don't know how justified. I have no opinion of my own in that sense.
However, they were primarily manufactured by Bendix, which was purchased by Continental. Now, Lycoming was the only engine manufacturer that used them in any wider sense. Obviously, the main rival had no problems in pulling the plug off the production line, which they did at around 2000 if I recall. Therefore, only overhauled units are in circulation, and I don't know how is the availability of the service parts nowadays. Regardless, it was more difficult to find service support for duals than for regular single magnetos, as is usually the case with 'exotics'. But again, I'm not sure of the current state of matters.
They obviously give up some of the redundancy, but then again, Bendix magnetos tend to be somewhat more properly built than the Slick ones, using a bit less of that brittle plastic. Obviously, with dual mag, if you had an issue in either side, the whole enchilada comes off. Good thing or bad, one could argue both ways.
pilottj wrote:The RV thread below got me a little dreamy about owning an RV-7 and how I would option it. Would I go with the 200hp IO-360 or the basic 180hp unit. Cost vs reliability vs performance..etc. As you say, and from personal experience, the basic Lyc O-360 is about as bulletproof as they come. I remember my training days flying a flightschool's fleet of O-360 powered 172s what with all the student abuse they put up with and kept on ticking.
Keeping the engine happy is my biggest concern when flying. I don't mind flying a few knots slower if it means the engine is 'happy'. Anyway, good stuff to think about.
Piper Arrow had 180 hp engine on it until it was changed to the 200 hp model. I don't recall any specific issues with either. Perhaps 'Arrow community' has formed some opinion of them. Or the Vans community. I'd expect the 180 hp Arrow guys at least making up some appropriate justifications for having this lower hp model, aside lacking money for the -200.
I doubt having that extra 20 hp would be a bad thing at all. Neither engine has any reputation of being troublesome, so they should run pretty happy with regular, proper operation. The engines that are more unreliable than others, have specific issues or require special care in operation are usually rather well identified.
-Esa
