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Thanks Lynn, do you have any guidance on runner diameters vs their length.
From everything that I've read thus far it would point to a nearly 20" runner
length but I've not read much about what diameters.
Lots to learn in the (my?) future :)
Jarrett
On Mon, 11 Apr 2016 15:38:10 -0400, Lehanover
<flyrotary@lancaironline.net> wrote:
For intake lengths, the ideal is the enemy of the good. There is only one
perfect length and diameter for each full throttle RPM. So a very large number
of lengths and diameters work very well for AC use. Tracy's Race winning engine
had rather short compact tube lengths and outran everybody. My racer has 170 HP
at 6,500 RPM and 250 HP at 9,600 RPM from a 12A engine with 2292 CCs. This with
a very large bridge port. The 13Bs you are building are bigger with
2,606CCs.
The engines tune like a 2 cycle dirt bike. The exhaust system makes a far
bigger difference than does the intake design. My Drummond built race engines us
a stock intake manifold gasket. The intake runners are polished but NOT
enlarged. You want the highest possible intake flow velocity at every RPM. The
intake manifold to mount a Weber 48 IDF has a plenum below each throat so the
actual runner length is very short. This in turn tunes a bit better at stupid
high RPM but works well enough to deliver good performance above 6,000 RPM. You
would not have to add much length beyond the stock lower manifold to be about
perfect for aircraft use. The HP is in the exhaust system. The side port engines
have fewer degrees of overlap than does a Pport (Massive overlap). Renesis has
no overlap at all. Smoother the idle for less the overlap.
Lynn E. Hanover
Racing rotaries since 1980.
In a message dated 4/11/2016 12:38:17 P.M. Eastern Daylight Time,
flyrotary@lancaironline.net writes:
Actually on paper I’m still the CEO of the company but
all the day to day operations are handled by Laura since my retirement. She
has been a great business partner.
Tracy
Sent from Mail for
Windows 10
Actually, The company is owned by Laura, Tracy's EX.
(reminds me of the license plate of a Mercedes, in my area," WAS HIS"
Although they don't have aviation parts any more, they still
stock a complete line of Tracy's seals, rebuild kits etc.
In a message dated 4/10/2016 9:28:09 P.M. Pacific Daylight
Time, flyrotary@lancaironline.net writes:
Sorry for lack of detailed
info; I was away from home & pecking at my phone to reply.
Wayback
machine:
https://archive.org/web/
Tracy's old website was:
http://www.rotaryaviation.com/
which no longer has aviation
info on it (currently only car performance parts under different
ownership).
=
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