AviationBanter - View Single Post

**Matt Whiting** · July 24th 07, 03:49 AM posted to rec.aviation.piloting,rec.aviation.owning

wrote:
: Don't knock the O-200 quite so fast. The 162 is getting the "D" model
: engine, the Type Spec of which hasn't even been issued, yet. I would be
: surprised if Continental doesn't incorporate some improvements to the
: cylinder design. As a rugged, easy-to-maintain light aircraft
: powerplant, I personally think they made a good choice.

I'm not "knocking" it so much as I lament a brand new aircraft not using new technology. TBO doesn't take into account
cylinder overhauls, which are routinely required on old-school air-cooled aircraft engines. I'm been plagued with sticking
valves on my O-360 since I got my Cherokee and taking a step *backwards* from that (WRT cooling, compression ratio, etc) seems
silly.

Newer technology isn't always better. Airplane engines have evolved
very well to meet the requirements of the airplanes they are in. Sure,
some improvements seem pretty obvious such as fuel injection, electronic
engine management, etc., but I'm not sure what I'd change to the basic
engine architecture. For an airplane, an air-cooled engine with
separate cylinders makes a lot of sense. A water cooled mono-block
design would add a lot of weight and make field overhauls much more
difficult. And water cooling adds several more failure modes (water
pump failure, hose failure, thermostat failure, radiator failure, etc.).
I'd say that with respect to my automobiles over the last 30 years
that I've had more problems with the cooling system than with any other
part of the engine.

Matt