Earlier, (Dick Kurtz) wrote:

looking at potential powerplants
for my project I have come across a
TSIO- 520...

One thing to watch out for with the TSIO and TIO motors, is that they
often (at least, the ones I've seen) have the exhaust coming out the
upper side of the cylinder head, and not the lower side. That means
that you might end up with a funky exhaust system, and perhaps a funky
cowl. Also, it might make it harder or more expensive to get
replacement cylinders.

Also, and perhaps more important, most of these engines I've seen in
their natural environment are updraft-cooled, for example PA-31. It
might be that they work OK with downdraft cooling, but I'd bet that
with the exhaust on top it's going to be a bunch less effective, since
the exhaust manifolds will tend to pre-heat the air before it goes
through the cooling fins. That might not be the case, but it's
something to think on.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com