Cessna's new LSA: "Skycatcher"

Jim Stewart wrote:
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.

If the "D" models has the improvements you suggest, then it's a
good compromise. If not, it's a rather disappointing choice. Perhaps
with 110 HP it'd go faster than allowed in a LSA?

Another issue is the reduction gear that
comes with a 912. If you value the lower
vibration levels and more optimum prop
and engine rpms, it's a benefit you don't
get with the Continental.

Is the prop RPM in cruise really any lower than a Conti? Most reduction
units are simply to get the prop RPM low enough to decent efficiency and
seldom get much lower than a direct drive airplane engine.

Matt

"Matt Whiting" wrote
Is the prop RPM in cruise really any lower than a Conti? Most reduction
units are simply to get the prop RPM low enough to decent efficiency and
seldom get much lower than a direct drive airplane engine.


The reduction gear ratio on the 912S is 1:2.43. This means a prop RPM of
2386 rpm at max power and around 2000-2100 rpm in cruise. Very sweet and
efficient.

Snowbird wrote:
"Matt Whiting" wrote
Is the prop RPM in cruise really any lower than a Conti? Most reduction
units are simply to get the prop RPM low enough to decent efficiency and
seldom get much lower than a direct drive airplane engine.


The reduction gear ratio on the 912S is 1:2.43. This means a prop RPM of
2386 rpm at max power and around 2000-2100 rpm in cruise. Very sweet and
efficient.



I don't have the efficiency curves handy. That sounds pretty slow for a
small diameter prop.

Matt