[YankeeClipper]

I am only a student of 25 hours at this point, and while I fully appreciate the need to get more time in single engine, non-complex aircraft first, the Skymaster has remained at my 12 O'clock these last few years. In that time I've read numerous threads about alternative engines that discuss, among other things, what has already been done and the risks of trying to component-engineer new solutions in general. What I haven't read (and perhaps just missed), is discussion about replacing the native power plant with the other IO-360. I am of course referring to the Lycoming.

I understand that this is ten HP shy of the TCM, but with commensurate adjustments to one's mission (e.g. mtow) I'm wondering if there aren't any advantages to this. The weight is about the same, the cylinders fewer (i.e. fewer points of failure), the manufacturer's TBO 33% longer, the rebuild cheaper by about $3-5k. It is also smaller (i.e. more room under the hood). I suppose I could also raise the specter of crankshaft issues but I'll leave that debate to the myriad other threads on the topic. There is also the TIO variant which isn't much larger (same dimensions as the TCM), that returns the aircraft to original power, and has the altitude benefits as well (though not of course the maintenance/cost ones). Finally, folks can go many rounds on this brand vs that, but the digest of many, many hours of reading seem to indicate that they are at least comparable in quality and reliability. If anything, my reading has favored Lycoming ... though again, I'm only a student, and it is only the digest of one man's reading.

My other thoughts:

* with similar performance specs, no torque, vibration, weight distribution changes to airframe

* Needed changes include engine mount redesign and possibly prop offset if fitment in cowling requires it.

So the question is simply, what are your thoughts?