On Tue, 29 Jan 2013 00:54:06 -0600, wrote:

On Mon, 28 Jan 2013 13:59:21 -0500, wrote:

Yea, I know they have cooling fins, but hey, people use them all the
time when the outdoor summer temperature is in the 90s, and the air is
still. Often they are just sitting at idle. How can they be getting
cooled properly? Yet they seem to last a long time in most cases. Those
find cant be doing much when there is no air movement, and usually no
fan either....

Are they built from stronger metals than a car engine?
Nope - usually crappy aluminum aloys

Then how do they hold up?
Design. And they do not stand up all that well - many have a
"published life span" of as little as 300 hours.

The heavy duty engines like the OLD Kohler and Wisconsin engines were
heavy cast iron, and ran almost forever - but their horsepower per lb
ratio was disgusting..

The horsepower per cu inch displacement of the small engines is also
very conservative, to put it mildly. (except in the case of the high
rpm super lightweight 2 strokes).