ORIGINAL: Mode One
I asked this question in the general "Questions and Answers" category, before I found the engines category. I think this is a better place to ask, so here goes. It is a known fact that inverting an engine, can make it difficult to start and may decrease the reliability of the idle. Clarence Lee (an engine guy whom I have the highest regard for) as recently as within this last year has talked about the problems of inverting an engine. The question was about inverting a 4 stroke and Mr. Lee strongly suggested the addition of an automatic glow plug driver.
The question is; Inverting can cause reliability problems, so why are manufacturers producing more and more airplanes designed for inverted engine installations? This seems especially true with 3D airplanes! Most 3D designs are not scale, so why invert? In an all out competition scale airplane, I can almost see and can understand why some people invert, to hide the big cylinder. However, I have to say, I just don't get it!
Obviously, we (as R/Cers) are O.K. with this as the manufacturers keep designing airplanes with inverted engines.
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The simplest solution is to buy only engines that come equipped with pressurized or pumped fuel delivery systems. Problem solved. Personally, I would stick with YS. All non pumped/pressurized fuel delivery system engines are a crap shoot. Of course, there are various after market pumps and pressurization systems which can help. But you have to be careful as to which one you choose. It has been reported that some will not prevent fuel from draining into the engine from a higher positioned fuel tank.