Tom,  The P-Ports will be NC milled.  I don't think it is necessary

to thread the insert although this is what Jim Mederer says.  I know
that others have not threaded and have not had problems.   The angle
of the insert is another question.   I would prefer it to be
perpendicular to the housing. However,  this places the runner at a
weird angle if you intend to go over the top of engine.  Better to
just have a couple of 90 degree bends that can be readily bought.
I
am not locked into anything yet.   The P-Port timing is still a
mystery to me.  I tried to compare Paul Yaw's numbers with the tech
drawing of the Lemans ports and they did not coincide.  Maybe I did
it
wrong.    I would be  happy to just copy the Power Sport ports, if
only I could.  Jerry
--
Jerry Hey

Quite an effort going on here. My I suggest that the runner should be
parallel with the horizontal. The bottom edge of the port left sharp,
with
just a hint of a radius. This to reduce exhaust gas dilution at low
speeds.
The top of the port with a larger radius, for improved flow at high
speed. I
would go easy on the closing event compared to the Lemans engine. You
can
always extend the closing event with a die grinder later.
Even with a poorly done port, the power will be beyond impressive.
The first
time we ran a 12A periphery port, the driver reported oil on the rear
tires
or a slipping clutch.

He had never experienced wheelspin before. The Lemans ports appear to
be much
larger than the factory 12A ports. The steep angled port would be
easy, and
would work OK, but that is not what the factory did. Here is the
start of a
home built Pport.
The timing copied from a factory housing.
Lynn E. Hanover

Is that a factory 12A PP on the bottom?

We shouldn't forget that turbo timing should be different too.  Racing
Beat offers turbo and NA versions of their PP housings.

Hans

 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2002 All world wide rights reserved.