RCU Forums - View Single Post - Another Perry Pump and OS 160FX question!

05-23-2009 | 11:55 PM

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DarZeelon

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From: Rosh-HaAyin, ISRAEL

RE: Another Perry Pump and OS 160FX question!

Quote:

ORIGINAL: kiwipaul

In my earlier message I mentioned vibration as the cause of fuel foaming. The foaming is inside the motor not the fuel tank. I have not seen air-bubbles in the fuel lines at any time weather bench running or in the plane itself.

Paul,

The amount of fuel sucked inside your engine's crankcase, while it is running at full throttle is ~ 0.0133 cc (0.000476 oz.) per cycle...
It is not left waiting there and is delivered into the combustion chamber
This quantity is not sufficient to be 'churned' into foam.

At low-throttle, some fuel will 'puddle', but the vibration level is much reduced...

Your statement is not realistic.

Quote:

Glow fuel; whether it be Cool Power, or Omega, will attract moisture from the air. All motors have some fuel residue left behind even when run dry of fuel. That is why the bearings rust out, minutely at first, but will get worse as the motor is used.

Fuel that contains a sufficient amount of castor oil, will have enough of it thoroughly coating the bearing races and balls; thus preventing their contact with the moisture accumulated by the hygroscopic methanol.
Running the engine dry at the end of EVERY flying day, will reduce the amount of raw methanol left in your engine to a bare minimum, so, there will not be 'washing' of the tenacious castor oil from the bearing surfaces either.
CoolPower oil, Klotz Techniplate and most other American made synthetic lubricants, simply are not endowed with the strong tendency of castor oil to remain on metal surfaces.

I never had to replace rusted bearings, in any engine that I ever owned - I also have never use any CoolPower (or any other all-synth), for over 16 years...
One of my engines has over 150 hours and original 52100 steel bearings. No rust!

See the connection?

Quote:

Myself and two friends have had this problem with the OS1.20AX, OS1.40RX and myself with OS1.60FX. Changing to stainless, or ceramic bearings cured the erratic tuning problem.

This is purely circumstantial... Stainless steel bearings do offer greater resistance to corrosion and silicon-nitride balls cannot rust...

Besides, for some reason, OS engines seem much more prone than others, to rust in their bearings.

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