From: Lehanover@aol.com
Message-ID: <9c.3551e87e.2c9ae898@aol.com>
Date: Thu, 18 Sep 2003 06:53:12 EDT
Subject: Tuned Length
To: flyrotary@lancaironline.net
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I was looking at a dyno sheet from my 12A, (2,292ccs) and I have 173.3 HP at 
6,500 RPM. 

This is with an intake manifold for a car that is making best power at 9,400 
RPM.
A very short compact intake that looks like the Racing Beat manifold. I was 
talking Daryl Drummond at Mid Ohio yesterday and he confirmed he had the 13B up 
to just over 300 HP at 9,100 RPM. A bit steep for aircraft use but it gives 
you an idea that maybe the deep concern over tuned lengths is maybe less 
important than some people think it is. These are bridge ported engines, but you do 
that with a drill press and a die grinder. The engine weighs a bit less when 
you get done, and you don't need a turbo to post the big HP numbers. My 12A is 
required by the rules to breath through two 38MM chokes. The 13B has two 44MM 
chokes. So each rotor housing gets one choke. I will send a PDF of the sheet 
as soon as my wife shows me how to do that. Don't laugh, she can build a rotary 
too. 

Lynn E. Hanover