Paul,

Last week I manage to take some pictures of the jigs used for
making   identical housings based on this cut off test housing.These jigs
with
positioning dowels and through bolts have evolve to accept casting
plates for the DEVCON epoxy, or  hardened steel  plates with drill
inserts to drill the hold down stud holes for the throttle.
Ditto a
plate to drill the  fuel injector bore holes and the injector hold
down
plate studs. As of today these jigs  also have  quick release
air hose
connectors for leak testing.

Pict . 007  The p-port  final step cutter I made installed in
the end
mill. It is set at a 56.3 mm OD.  Works like a champ.  Not
shown is
the
P-port insert 56 mm OD 50 mm ID  which has O-ring grooves cuts
to seal
on the inner and outer sides of the water chamber.  It of
course slips
into the port hole. No welding needed and is removable, inspectable
and
changeable. Held there by the throttle Plate.  Throttle to be
fastenedto the housing by four M5 studs that also hold on the
intake manifold.

Pict, 080. My design of a  low profile low restriction throttle.
Why?
In my application slide throttles are cumbersome and won't get
me up
close and personal to the p-port as I would prefer. Hence the
throttleopening is  over sized  to compensate for the 1.5mm SUS 304
thickness of
the throttle plate.  It is 53 mm ID. The  throttle plates (two
neededand two to screw up trying) are laser cut ellispes,
slotted and to be
TIG spot welded in situ to the slotted 6 mm Stainless 303 shafts.
Center
hole is for jig positioning. 303 on shaft is much easier to
machine a
1.5mm slot into while the material  still has good corrosion
resistance.
Shafts shown are not  profiled yet for minimal  air resistance in
WOT.
Ditto the  throttle plates  but they will be.  One shaft will not
protrude from the throttle plate.  The other to the central housing
spring and cam location. Good advise courtesy of  Kinsler. Now
lookinginto baked on teflon paint coatings to see if they have
any measurable
merit in lowering air resistance in the intake manifold parts.  It
does
on prop blades.

Bearings are NTN BEAREE a tough fluorcarbon plastic which is harder
but
more slippery than Teflon. I believe this is the same material
used in
motorcycle throttles. This material  has been tested on our wind
generator swing tail rudders for three years in the field.  These
tests
are equal to several million  swing cycles with no failures, at
leastnot in the bearing.  Earlier tails had to be strengthened
as they got
beat up in the winds.  Google "Airdolpin wind turbine" to see
it in
action.  Now on sale in USA.

Other updates as they happen.  The next challenge is to cast a near
perfect finished epoxy face on to a new housing and have it
free of
inclusions.  That requires a liquid AL. DEVECON and application
of a
vibrator.

Doug in Japan

How about applying vacuum?

Chris Cosman

Hi Chris,

Good idea in theory but the forms would need to be a  tight fit on the
various curved surfaces.  The force of gravity is adequate and the end
of the pour will be on the top edge of the casting which is easy to
level with a hand dremel tool.

One trick is to pour the liquid down a rod inserted into the
cavity.Then a use a large industrial  vibrator or the type they
sell for
shoulder stiffness for a few seconds and any bubble will just pop
to the
surface.

Doug in Japan

Fwiw, the best DIY vibrator I've found is a standard $25 [harbour freight??]
corded power drill [hammer style] w/ a pc of solid shaft [1/4- 3/8"]
sqred on the end, in the chuck. "Hammer drill"  the side of
something w/ it and it works like a charm. I've used it to help
fill concrete molds and such and it worked very well there.

Fwiw

Jarrett