Subject: P-port intake]
From: Rotary Engine
Date: 5/3/2009, 7:02 AM
To: AAA Put this in the To box


A few questions on P-ports:
- If you are using a slide throttle on a P-Port do you really need runners?
-Couldn't you use a large quad oval air intake attached flat, on top of the slide throttle and be done?

-If you have an inner SS sleeve welded to the inner surface of the housing and
an aluminum exterior outer flanged sleeve welded to the outside of the housing
why couldn't you use a flanged tubular wedge bolted down into and between the
inner and outer sleeves from the outside to forcibly seal the gap and maybe
add some sealant or high temp gasket on the inner and outer surfaces of the wedge?

Seems like the tubular wedge would provide an extended sealing surface area
between the two tubes and the water could still circulate to some degree
without entering the combustion area or the intake area.   Wade Bush

Yes we do need runners. The rotary is nothing with out runners.
The engine is very small in displacement terms. Only 160 cubic
inches. Therefore as a simple air pump it would be lucky to generate
110 HP. No air no HP.

Back in the early days when the Mazda rotary did not have runners
that was about the amount of HP the first Mazda rotary engines generated.
The engine is the same displacement now as it was in 1974 when the
13B was first introduced. The HP has over doubled over the years
due to advancement in runners and porting and a bit more RPM.

I am not sure I follow you on the rest of it. I will need a drawing
to visualize a "flanged tubular wedge".

Paul Lamar

Is it even possible to TIG weld an aluminum tube onto the outside of the
aluminum rotor housing? If its not forget it - the idea wont work.

I dont have a 3D drawing program but think of this:

A cone shaped wheel bearing tightened onto an axle between the axle and
the wheel hub. The tighter you make it the more snug the fit.

The axle represents the inside SS tube
The cone shaped bearing represents the flanged tubular wedge,
The wheel hub represents the flanged external / outside aluminum tube.

Does Mazda or someone make a P-Port housing?

What is the ideal intake length and is that measured from the
inside surface of the port or from the throttle face?

What program do you use for 3D modeling?

Wade Bush

The jury is still out on tig welding an Al tube to the outer
part of the rotor housing.

Yes Mazda makes a p-port rotor housing but I think you need
a special permit in effect to buy one. Not cheap. Other outfits
also make them Like Racing Beat. For peak torque
at 6000 RPM optimum diameter AND lenght is about 24 inches
plus or minus 2.

I use Rhino 3D. http://www.rhino3d.com/

Paul Lamar


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