> > >Jerry Hey wrote:

 > >>
 > >>  Paul,  how about designing the pp intake system for me and all
 the
 > >>  other guys who are thinking about it.   I think we should come
 very
 > >>  close to Power Sport's design.   Could we  use   your intake
 parts
 > >>  for the cold side stuff?  They  are 1.5o.d. which is what I was
 > >>  thinking of for the i.d. port size which I got from your drawing
 on
 > >>  the ACRE site.  If we can match these (or do they need to be
 > >>  matched?) that would make it a lot easier.   And look good, too.
 > >>
 > >>  Maybe we can find a throttle body that was used on a production
 car.
 > >>  New, high performance throttle bodies that I have looked at on
 the
 > >>  internet are expensive.
 > >>
 > >>  I will commit myself right now to providing housing machining and
 the
 > >>  inserts unless someone else wants to do it.
 > >>
 > >>    Jerry
 > >>
 > >>  p.s.  The first structural change to the Tailwind caused by
 rotary
 > >>  performance  is a thicker windshield.

 > >If I were doing it I would copy the Leman engine porting exactly
 > >except put the butterflies next to the rotor housing.
 > >240 HP at 6000 RPM and a lot more at 7500 with a 2.85:1 PSRU.
 > >You don't need a throttle body. Just a couple of home made
 > >butterflies. You also don't need my castings as everything is
 > >too simple and can be made from tubing. Scale up this
 > >drawing for the same size tubing Mazda used on the Leman
 > >engine.
 > >
 > >Thicker Windshields are a good idea anyway. That reminds me
 > >I need to get one for the KIS.
 > >
 > >Paul Lamar
 >
 > Do the home made butterflies need bearings, seals, return springs,
 > throttle position sensors? Am I making this too complicated?   Jerry

 You don't need throttle position but some small SS shielded flange
 ball bearings would be nice. You can get these from:
 W.M. Berg
 Stock Drive Products
 Sterling Instruments.

 I think I have some quarter inch versions lying around I can send
 you.

 Paul Lamar

 Looks like the same bearing used in roller blade wheels.

 T. Webber

Godd source :-)

Paul Lamar

OK.  I will take a shot at making the butterflies.   One last thing:
in the drawing you sent of the Everett Hatch Style  ports,  the bore
of the section that is inserted is less than the bore that contains
the butterfly.  Is this necessary?  What is the smaller bore?
Could one use a 2" o.d. x 1.75" bore for the whole thing?  Jerry

Not clear form the drawing put the part than goes in the housing
is square.

You would not get as much power as the Leman engine.
But if that is OK go for the 1.75" bore. If it were me I would go
for a two inch bore and 2.25 OD tubeing. Why mess around? You are 
going to cut holes in rotor housings anyway.
Are you going to start with new housings?

The area differnce is:

A 1.75 inch bore = 2.4 square inches.
While a 2 inch bore would be 3.14 square inches.
30% more area.

Paul Lamar


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