Mark,

For the '86 OMP that I use, the two front ports of the OMP deliver oil to the rotor housings, the upper one to rotor 1 and the lower one to rotor 2.  The two rear (flywheel end) OMP ports deliver oil to the primary runners of the lower intake manifold, the upper one to rotor 1 and the lower one to rotor 2.  The OMP is a positive displacement piston pump which operates similar to a diesel injector pump where the piston reciprocates (with the stroke determining the volume delivered) and also rotates (with the rotation position determining which ports the oil is delivered to).  The piston on the OMP has two different sections of different diameters with the larger diameter section delivering oil to the front OMP ports and the smaller diameter section delivering oil to the rear OMP ports.  The diameter of the larger section is 3.75 mm (3.52 sq mm area)and the smaller section diameter is 2.65 mm (1.76 sq mm area).  Since the two sections are part of the same piston, the strokes of the two sections are the same, varying from 0.25 mm to 2.00 mm depending on the control rod position.  So if one were to connect the two rear ports together, that line would deliver the same flow rate of oil as each of the front ports.  This would give 3 lines of equal flow rate.  You would have to decide whether to deliver the oil to the housing or the intake runner whereas the '86 setup did both.

The total oil flow rate for the 3 rotor engine would be in the neighborhood of 2/3 of what the two rotor engine received relative to the amount of fuel used.

It appears to me that the stroke of the '86 OMP could be increased from 2 to 3 mm with judicious use of a die grinder, which would make the oil delivered to each of the 3 rotors equivalent to the stock flow rate.  This might not be necessary and I haven't tried that.

Steve  ________________________________________
From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Mark Steitle [msteitle@gmail.com]
Sent: Monday, April 09, 2012 8:12 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: OMP Plumbing

Tracy,

How should I plumb the 4 lines for the 3-rotor.  From your
explanation, it seems it should have 6 lines (2 per rotor)?  Even the
20b OMP only has 4-ports. Should I split the 4th line into three
separate lines?  Do you know of anyplace where I could read about how
OMPs are connected from the factory?

Thanks,
Mark