![]() |
ECI-360 oil pressure problem solved
I've been BUSY building my -14, but still managing to take the -9A up once per week or so. Anyhow I've been having a bit of a low oil pressure problem on it recently. I've been running the motor at 5 quarts, because that's where it seemed to be happy. Well, the last two flights the oil pressure has been around 55 psi. That's 15 psi lower than I am used to. Well, today I wiped down the dipstick (It has markings every 2 quarts, so 4, 6, 8, etc. quarts) to service up the oil. Turns out I have been running it closer to 4 quarts than 5 quarts. Good thing the minimum is 4 quarts.. phew.
I have not flown the airplane yet (tomorrow), but I suspect now that I am up around 6 quarts, my oil pressure "problem" will be gone. Moral of the story: with the dipsticks that only read every 2 quarts, it's hard to tell where the middle quantities lie. My takeaway is, just keep the **** motor at 6 quarts and call it good. |
Don't know if this applies...
But I put it out there for folks who aren't aware:
https://www.lycoming.com/sites/defau...acement%20.pdf |
Quote:
|
Oil Pressure
For parallel valve engines with standard sump 6 qt oil level will have no effect on oil pressure. IIRC the Lycoming minimum for these engines is 2 1/4 quarts.
Some angle valve sumps require a higher minimum oil level. Lycoming's or Lyc clones like high oil pressure. A sudden drop of 15 psi should have required an immediate investigation. Could be as simple as trash under the oil pressure relief ball or it could be something really bad. Oil pressure near the top of the green arc is beneficial to the valve train. There is no downside to high green oil pressure. |
Make your own calibration for your specific set up. No way the same engine installed on a nosewheel aircraft reads the same oil quantity as if it were installed on a tailwheel aircraft. Or if the sumps are changed to cold air intake types.
Add 3 qts and put the dip stick in. Make a mark on the dip stick. That should be the lowest amount. Then add 1 qt at a time and mark it. You will soon see that the measurements are not linear, meaning just because you see oil between 4 and 6 does not mean you have 5 qts. |
As a point of clarification, the Minimum oil quantity for most parallel valve Lycoming (I)O-360 engines is 2 US Quarts.
However, notable exceptions are the IO-360-M1A and IO-360-M1B, which have a 4 US Quart Minimum. Ref: https://www.lycoming.com/sites/defau...2060297-12.pdf |
Oil
The M1A appears to have the same or similar sump as early angle valve 360's. it is wider and flatter, hence the need for a higher minimum. That sump is popular with builders who wish to convert a parallel valve engine to front mounted injection on a reasonable budget.
|
Quote:
I know that you say that it should not make a difference, but I serviced with two quarts of oil yesterday, and went flying today. Oil pressure was in the high 90's on takeoff with the oil temp around 110 degrees. With the oil temp around 180 degrees in cruise, the oil pressure settled back in to around 80 PSI. So, while you say that adding oil should not make a difference to my oil pressure, in my case, it most certainly did. Thanks for the input. If you have any thoughts, feel free to share them! Always learning... |
If adding oil makes a difference to oil pressure, it would mean that the oil pump was sucking air previously. They are a fixed displacement pump. If the inlet to the pump is under the level of the oil then the pump produces flow (against restriction) and the amount of restriction, rpm of the pump, as well as the viscosity of the oil, determine the pressure of the oil in the galleries as seen on the gauge.
Mike Quote:
|
Oil
Quote:
Also be aware that there is a oil suction screen in the sump that most guys don't know about. Not the oil pressure screen, or oil filter, but the one that catches junk before the oil pump. I cleaned one before and the pressure came up quite a bit. . |
| All times are GMT -6. The time now is 09:21 AM. |