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From: "Steven W. Boese" <SBoese@uwyo.edu>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] Re: OMP Plumbing
Thread-Topic: [FlyRotary] Re: OMP Plumbing
Thread-Index: AQHNFlrydu6BTIiO7Em9xzznCiGsLJaSs91I
Date: Mon, 9 Apr 2012 17:15:48 +0000
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Mark,

For the '86 OMP that I use, the two front ports of the OMP deliver oil to t=
he 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 r=
otor 2.  The OMP is a positive displacement piston pump which operates simi=
lar to a diesel injector pump where the piston reciprocates (with the strok=
e determining the volume delivered) and also rotates (with the rotation pos=
ition determining which ports the oil is delivered to).  The piston on the =
OMP has two different sections of different diameters with the larger diame=
ter 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 s=
ection 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 t=
wo rear ports together, that line would deliver the same flow rate of oil a=
s each of the front ports.  This would give 3 lines of equal flow rate. =20

You would have to decide whether to deliver the oil to the housing or the i=
ntake 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 fue=
l used.

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

Steve =20

________________________________________
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=