John, according to my calculations at 4750
rpm (depending on your Air/Fuel Ratio), the engine should be producing around
135-145 HP. Your 4750 rpm is a bit lower than what I would normally expect
from a 2.17:1 gear box, but seeing as you have the engine a bit heavier loaded
with the 2:1 gear ratio – you are probably going to pick up more RPM as
you gain speed after liftoff and unload the prop a bit.
So long as you have a decently long runway
– I would say you are producing sufficient power – Ah, as I recall
a TAILWIND was originally designed to fly on 85 HP, so you should have more
than enough power {:>)
Looks like to me that your engine is ready
to take that first flight.
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of John
Sent: Monday, May 24, 2010 10:16
AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] fuel system
& numbers
Understandable I had to reprogram the computer this morning
to compensate for the fuel that was seeping into the Weber. Here are the
numbers OAT 78, MAP 28, static rpm 4750, prop 2375, water temp 190, oil temp
160, fuel pressure 40. These numbers are after 20 minutes running with
the top cowl off so I could run it full throttle without over heating. If
these numbers look good to you folks, it looks like it is ready to
fly. JohnD...13B w/ 2:1 Marcotte redrive, Wittman Tailwind