> Doug,
> I can rehash any of those parameters for you, I just noticed that the > Mazda
> Factory PP opens a little later - this would give a little less over > lap. I
> did the 70 deg IC ABDC, off my degree wheel which is early because of > the
> size ( 2") and didn't want to get you into too high a compression zone, > but
> you could go to 75 deg or possibly even 80 deg  if you so desired. The
> angled port makes this doable and the initial IO start a bit later. > Still
> the duration would be the same.
> Consider it a work in progress
> Please advise.
> George (down under)

George,

To save you from re-doing the chart It sounds like it is best that I
finish drilling the P-port and then get back to you with the exact
location details. It is close to the Lemans which is slightly angled
downwards so that I have enough metal in the  seat to contact a 1.5mm
dia O-ring on the insert.

Injection events will be different for different rpms.  I'll sketch
these in as they are tested and it all speculation at this time.
For instance at low rpms (under 6,000)  there is enough time to inject
near the middle or end of the intake cycle away from overlap.

At top rpms I`ll need all the time available to get enough fuel in there
so the injectors will probably be squirting during the overlap at the
beginning and partially close intake port at the end of the cycle.  To
clarify, I find it easy to mark the beginning of the injection cycle
after the fuel injection ports are uncovered, :) which implies the
intake port is already wide open and exhaust overlap is on the decrease.

Rotor induced compression is not an issue as it begins after the intake
port closes and the fuel injection event has finished.

Remember the apex seal uncovers the fuel injection inlet ports open
almost the same time the inlet port opens fully.

Hope this helps

Doug


Doug I don't mind doing the graph a few times, the adjustment is only a few
minutes.

Just a reminder the compression actually starts just after BDC,  where the
volume of the chamber is at it's maximum, however it's not high enough to be
a problem until after IC.

I can't remember if your direct injecting into the inlet tube or just above
it, directly into the chamber, but that's not a problem either as the
compression is still not high enough to over come the injector pressure.

Can you give me a size and position of your exhaust outlet and I can put
that in the graph in the mean time.
George (down under)


George,

Injectors are in the housing just below the oil injection port and to
each side of it.
The exhaust port is standard 13B though I may have a pro put a slight arc
in the top of it to help it flow better.

Doug.

Doug,
I was thinking, it would be to your advantage to set up a degree wheel out
of some old parts of a housing, an old rotor and an e-shaft.

Make up a large degree wheel out of Perspex bolt it to the end of the
e-shaft and bolt a piece of flat steel to the inlet side of the housing as a
fixed pointer.

This aids (a hell of a lot) in degree identification - no measuring at all.
I know I should have dusted off the Perspex to make it look clearer, you
will see I scribed on the degrees in 5 degree increments and painted on (
paint pen) the numbers. The beauty of the Perspex is that you can look
through it rather than looking under all the time to line up marks.
I actually bolted on a piece of fiberboard and sat the Perspex onto the
fiberboard ( firm fit). This allows me to move the degree wheel without
moving the e-shaft ( for different measurements). It's a firm fit so it
doesn't move unintentionally.

This is an old 12 Housing so my exhaust is not the same as the 13 B, their
smaller.
Once your used to measuring in degrees, you wouldn't want it any other way.
Design  -courtesy of Lynn Hanover; with personal modifications
Hope that helps.
George ( down under)