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.     

 

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

 

From: ARGOLDMAN
Sent: Monday, April 11, 2016 8:29 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Intake Styles and Data

 

 

 

 

Thanks for the link.

 

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.

 

Rich

 

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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