Hello Pat
I ran a Posa carb for several years. I even ran it on top of the engine
during one test. First of all, please see
http://kr-2.aviation-mechanics.com/alert.htm The information may or may
not apply to any Posa that you decide to use. I ran a Supercarb because it
had mixture adjustment. The adjustment was crude and only slightly resolved
the problems you read about earlier involving the ability to run good at
midrange. As for the posa on top of the engine, mine started and ran better
on top. The problem was in getting the fuel up to the top and then the
problem that the fuel would run out of the carb until the engine started.
That would not be good on a hot engine, even if you had a tray to catch and
drain the fuel, If you want to run a carb on top, the only person I have
seen do it was Steve Bennett. He ran an Ellison with a drain tray. Having
been there and done that, I removed the Posa, not because it did not work,
rather because I wanted a smoother operation. I settled on the RevFlow, and
after playing with the needles for a while, feel that I run better in all
ranges. Much better then I could ever get from the Posa. I also tried the
Zenith carb for a few test runs and feel that for a smaller engine it was
smoother then the others, I just could not get it to pass enough fuel at
WOT, and the engine would run lean. Currently my fuel system is equipped
with a RevFlow, a fuel pump and a dialable fuel restrictor to regulate how
much fuel the carb gets. I have found that at 2366cc with the turbo, that I
can't get enough fuel at full power without the aid of the pump. During one
flight I was at high cruise power and turned the pump off and the engine
started to miss due to being too lean.
Orma
Southfield, MI
N110LR Tweety, old enough to drink this year
Flying and more flying, to the gathering or bust
http://www.kr-2.aviation-mechanics.com/
