You got your work cut out for you Doug making one
of these by hand.

Paul Lamar

Paul

Thanks for whipping up a illustration and yes but my work is not cut out
for me yet:)

I had something simpler in mind but I haven't got my Windoze computer
and hence Rhino up and running again to show you.  Maybe Larry can show
you what he has in mind.

Without any thick pipe on hand I was going to carve out an piece out of a
cylindrical 6061 billet which by luck  have several feet  of six inch
diameter in the shop.   Two main pieces it is. A  cylindrical shape
housing and the bottom outlet plate rabbit joining and sealing similarly
to the way the impeller goes unit is everything  and bolted together as
an assembly with four through long studs welded onto the mounting plate.
  Look at the late 12A early 13B oil pump housing and you can see that
cover with what used to be  front end engine mount.  That is the
location the plate bolts onto.
To make the job easier the inlets and outlets can be welded on.

Doug

The diameter is 73 mm. The tricky part is expanding the out put flow
from about 8 mm wide to something like a 40 mm pipe. The impeller is a scaled
down version of a 1930's era hydroelectric water turbine.

Frankly Doug, I think you are on a fool's quest. All the evidence we have is
the current 2nd gen 35 GPM pump is adequate to cool a 300 HP engine. None of
these people advocating more water flow have taken any hard data by
instrumenting the rotor housing. Mark Steitle, one who HAS instrumented the
rotor housing, has reported no temperatures over 300 F as I recall. Mazda
themselves say 400 F is as high as they have seen at 7000 RPM. Numerous Curtis
Wright tech papers say the same thing. People have flown with one tenth the flow
using a silly electric water pump for %^&*($#@! sakes and not melted the rotor
housing. Mazda themselves have cut the crude RX8 pump flow at least by half.

Four hundred F  is at least 100 F lower than an air cooled air craft engine
cylinder head temperature. Why is that? It is because the combustion chamber is
moving and the waste heat is going into a far larger surface area than you have
in piston engines. Cooling it beyond necessary will just result in less over all
engine eff. You need to re read my book. I'll ship the pump to whomever you
decide to sell it too.

Paul Lamar


Before everybody goes off on the deep end about expensive modifications to the stock cooling system and water pump it might be a good idea to find out if it is really needed. Here is all you need to know about rotor house temperature measurements.

Paul Lamar