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 fastened
to 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 throttle
opening 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 needed
and 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 looking
into 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 least
not 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