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Andrew Erickson

In article ,
wrote:

On Thu, 20 Aug 2009 20:21:25 -0700 (PDT), Robin
wrote:

I had a brainwave the other day about putting a small (300cc)
aircooled two stroke as an inboard in a small wooden boat. With
adequate air circulation can anyone see any potential issues here? I
would build the boat with this purpose in mind so adapting something
to fit would not be a problem.

Robin

How are you going to cool it adequately?

I would assume, for an air-cooled engine, that's where the "adequate air
circulation" comes in to play. One would probably have to be a bit
careful not to push the engine too hard too long, as well, since many
applications for these engines are not at steady high output. (There
are exceptions--ultralight aircraft engines for one example.)

I don't see any inherent insurmountable objections to doing this. A
speed reduction of some sort would be nearly essential, of course, or
else using a jet drive. Small two stroke engines in general tend to be
inefficient and noisy and smelly and a bit temperamental, although the
newer ones are vastly improved over older designs. On the other hand,
they are lightweight and generally unaffected by being off level
(limited mostly by the particular carburetor design), which can be
advantages for use in a small boat.

It's not as though there aren't a great many jet skis and boats with
older outboards zipping around just fine with two stroke engines every
day. Granted, most of these are water cooled, but still...

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot