> > Fred Vandeman wrote:
        > > >
        > > > As many/most of you with aircraft instillations......I
will
        > > be supplying
        > > > oil to the apex seals by putting 2cycle into the fuel.
        > > I'm finishing
        > > > my 20B overhaul and will be closing the front cover
        > > tomorrow.  Should
        > > > I remove the drive gear and shaft........or leave it

in?

        > > If it were me I would take it out. No telling what it

would

        > > do with no load.
        > >
        > > Paul Lamar

        > The roll pin (red arrow in pix) squirts oil onto the oil

pump

chain. I
        > was not sure if it would get enough lube without it so I

left

mine in. I
        > took the gear off though, so the shaft no longer rotates.

If

you remove
        > the shaft, oil will just run out the end of the bore.
        >
        > Chuck Dunlap

        Good point Chuck. Sorry I missed that.

        Paul Lamar

        I removed the gear/shaft asembly and threaded the shaft

(inside

and out) for pipe plugs.  Therefore, the shaft is pressurized and

the

oil pump chain is still lubed thru the roll pin hole.

        Ken Powell

I'm replying via a web browser... So if this gets tacked onto the front

of the

message instead of the end, my apologies.

I just pulled the gear and shaft for my oil injection pump, and threaded

the

hole of the front cover oil supply gallery to take a 6mm setscrew.

Seated in

the oil gallery just fine, and used a little lock-tite to keep it there.

Now the front cover of my 20B looks just like that of a 13B, and there's

no

roll pin in it anywhere... just a hole.  Looked to me like that's where

the oil

came out of the metering pump shaft after doing it's job.  Guess I'll

have to

go back and look again.  At least the plug is reversable!

Tom Kendall

I am not so sure that lubes the chain. It might have that effect but
I think the hole is mainly for the roll pin which I assume keeps the
shaft in place. If it were not for that roll pin the metering pump
gear could become disengaged from its drive gear upon assemble. I
think there is plenty of oil coming out of the front main bearing
and splashing around in there to lube the chain.

Come to think of it I am sure of it as just to the right of
that roll pin is the vent for the oil reservoir for the injection
pump. That is vented to the near atmospheric pressure in the
front cover. Therefor no pressure ... no squirt.  We went around
and around about this quite some time ago.

Old message below.

Paul Lamar

***********************************************************************

From:   Paul <rotaryeng@earthlink.net>
          11/15/2000 22:36
Subject:   oil injection pump


Somebody mentioned they thought the oil injection pump was not a pump at

all

but just a metering device that relied on engine oil pressure.

Not the case. The oil injection pump is indeed a pump and is gravity fed

with oil at

atmospheric pressure. The pumping action comes from the fact that the

plunger

moves up and down in its bore as shown in this drawing from the Mazda book
called "Rotary Engine". The stroke of this up and down motion hence the

amount of

oil injected is controlled by the throttle opening linkage.

The mechanical  pump is an off the shelf motor cycle part bought out by

Mazda.

As I recall it is made by Mikuni.

Paul Lamar

Paul, you may recall that one member of the list found the pin hole size
lubrication hole for the chain in the housing of the oil pump.  Found that
it squirts out a steady stream of oil on the chain as it goes by.

Ed Anderson

Yes I do vaguely. Was that you? :-)

Here is a sketch that I hope will clear this up a bit.

Paul Lamar
 
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