Engine power question???

In article .com,
wrote:

On Oct 10, 9:17 pm, "Kyle Boatright" wrote:


Don't confuse thrust with HP unless you're using the exact same prop and
prop RPM. An 0-360 powered Robinson R-22 generates what, 1500 lbs of thrust
because of gearing, disc area, etc? But, that thrust is only effective in a
narrow (vertical) speed range. The same engine, combined with an RV-style
cruise prop, would only generate (WAG coming) 250 lbs of static thrust.

That Soob had the same diameter of prop and ran at the
same RPM. I'm aware of the diameter/RPM/pitch effects, and that's why
the results were so startling to me. The 150s performance was much
better with the Soob, confirming its output. So either the Soob
produced more power than claimed, or the O-200 was really sick. Yet
the guy said that the O-200 was OK and the 150's performance with it
was typical.

Dan

I have a friend who put a Soob in a homebuilt, with "help" from the Soob
conversion people. I told him that I was not impressed with some of the
design (especially the cooling installation) and to be sure to make a
lot of test flights.

Well, it lasted to just short of Oshkosh and then from Oshkosh to just
short of Dayton. Fortunately, the plane was relatively undamaged; my
friend's ego was his sole injury.

In short, tread carefully when going with someone's conversion.