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Date: Tue, 15 Mar 2005 15:40:42 -0500
Subject: Re: [FlyRotary] Peripheral port 26b Le Mans paper
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From: Jerry Hey <jerryhey@earthlink.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
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Mike,  the reason my ports are round are two fold:  First,  it is easy 
to make a round hole and second, for our rpms the round hole is 
adequate.  My throttle body's walls are thick enough that one could 
make the port considerably larger with a die grinder.  The finished 
shape would be a rounded rectangle similar to the exhaust port.  I 
believe that the ported housings sold by Racing Beat have round ports 
unless they have changed the profile recently.  That is the way they 
used to be.     Jerry


On Tuesday, March 15, 2005, at 01:17  PM, Wynn, Mike wrote:

> I am sure many will have seen this already:
>
> There is a paper on the R26b Le Mans engine at www.mymazdarotary.com 
> under
> the `Mazda rotary general' tab.
> This peripheral port motor used a variable intake length and crude 
> scaling
> from the drawings in the above paper suggests an intake runner 
> diameter of
> just over 2 inches and a length of 22 inches at 6000rpm and something 
> around
> 2 inches shorter at 7k.  Peak torque for this 4 rotor (448ft lb) 
> occurred at
> 6,500rpm when runner length appears to be about 21inches.
>
> A couple of questions:
> Jerry: why is your inlet port round - in two strokes they are more 
> often
> oval, presumably to maximise flow for a given `valve opening'.  I 
> guess this
> is convenience for manufacturing???
>
> Anybody: does the PP geometry make it much easier to make Al end 
> plates and
> is this the easy route to much lighter engines?
>
> Lastly does anyone know where I can get some more information on PPs?
>
> cheers
> mike
>
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