I guess your saying that the oil cooling jet
hole will reduce the total oil pressure, so that's lost either way -
didn't think of it in those terms, but your absolutely right!
Although I must mention on the single rotor- I
don't have a centre iron, but I understand what your saying.
The second option sounds better to me. Perhaps three 1.5MM holes directly
behind the combustion chamber through the oiling groove. The oil lost to
cooling is lost to the bearing no matter what.
You could drill three different sizes of hole, each set 120 degrees
apart. Drill three holes in the bearing groove, slightly bigger than the
largest cooling oil hole in the rotor. Grind off the alignment tab on the
bearing.
Press the bearing in with the smallest set of spray holes lined up with
the large holes in the bearing.
Test the engine with a temp sender in the drainback gallery in the center
iron where all of the cooling oil returns to the pan. Run the engine hard with
each set of holes lined up in turn, and compare the data.
Since you are feeding one less rotor bearing with the stock pump, I doubt
that you will have any problem holding 80 to 100 PSI at speed. The engine will
/ may have poor oil pressure at low idle speeds, but this is not a problem as
the bearing area is adequate for two engines. If you can get an indication of
oil pressure, that is enough.
Lynn E. Hanover
In a message dated 4/7/2008 3:05:28 PM Pacific Daylight Time,
lendich@optusnet.com.au writes:
The second option, and I'm not so sure it's a
good idea, is to use the bearing lube hole and drill a 2mm hole in the rotor
bearing through to the rotor cavity. Apparently this works well for
delivering oil to cool the rotor, my concern is it starving the rotor
bearing of it much needed lubricant?
George ( down
under)