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

Doug,

If you are going to tool up and jig up to crank ONE of these out, how
about putting the word out and take orders?  I for one would be
willing to jump in line.  Well, let me qualify that to say we should
discuss costs.. .

Regards,
Gordon

Gordon,

I'd wait if I were you. The cost on the Lamar scale of acceptabilty is
most likely off the chart:)
I will test both Paul's cast remote housing with the second gen pump as
well as the BMW pump with a billet carved housing.  These types of
centrifical pumps are very efficient but the machining housing
tolerances are more severe, hence the $$.. BMW orginally tried to save
money and made the impellar out of plastic.  These impellars didn't
last long nor did the crude spot welded turbines replacements.
Stewart's unit has had only positive feed back on the bimmer sites.
Only one concern of mine, and that is if the turbine wheel itself has
been dynamically balanced.  The
mass does become a little flywheel at speed.  About 1930 turbine wheel
designs, I am not sure of that fact but I do know that most pumps were
designed before the Pyramids where built:)  Fair to say improvements
continued to have happen since then.

Paul
Please post the Stewards Components bad boy pump  over this way. I am not
going to give up before I start. Jeez! I will however test both pumps
plumbed through a hot engine block and heat exchanger and at steadily
rising temperatures and rpms. If you want the pumps mounted on a torque
arm I can do that as well. If the BMW unit performance is on par with the
Mazda pump then I will be happy to have solved a packaging challenge on
my engine. This is not an electric pump adventure and shouldn't be
confused as such.

Green tea sipping Mac lover in Japan.


No problem I'll mail it Monday.
I don't need the torque data. It would be of academic interest only.
1 or  3 HP is not going to make that much difference in an aircraft engine.
A car engine is an entirely different matter as the engine is running at only
25 HP or so. Remember... don't over cool. It is going to hurt your BSFC.

The ideal would be a 500 degree rotor housing all the way around.

Paul Lamar

Paul,

Ok that makes my life a little easier.  I agree the comparative hp
consumed is not that big an issue either way. If an increased  flow
happens I can always downsize the water heat exchanger surface area.  I
am limited in size and design in the location I desire at the moment so
that would be a good result.  Yes on cowl flaps.

Doug in Japan.