1flyingyogi
Well Known Member
I'll try to provide enough information, but not be too wordy about this very strange problem I've been experiencing.
At start up, I'm getting 79psi for oil pressure. By the time I take off and about 10 minutes into the flight, the pressure drops to about 76-77psi. (I'm thinking this is probably ok as the oil warms up, the viscosity changes and pressure drops). A few more minutes into the flight and it drops to about 74-75psi. As soon as I start doing aerobatics, it drops into the mid to high 60's. Negative Gs drop it much more quickly. Going back to positive G regains some of the lost pressure, but not much. Hard positive Gs also reduce pressure a lot. For example a hard 5G pull to a 45 upline or vertical upline will drop my pressure by about 5psi immediately. If I stop doing aerobatics, and fly level for a few minutes, the pressures come back up by a few psi, but never get back into the 70's. At it's lowest point, it's showing about 54psi (my alarm goes off at 55psi). If I pull the throttle way back (to about 2100rpm), point the nose slightly down, I'll regain about 2psi. Level flying back to the airport and the pressures will very slowly get back up to the high 60s/ low 70s by the time I'm turning final. Back on the ground, I'm back up to about 73psi. On other flights, it never even gets back into the 70's.
But I don't need to do aerobatics for the oil pressure to drop. Even "hard flying" (pulling 3G-4G turns, hard pull to 45 upline, hard push to 45 downline, etc.), or aggressive climb will cause pressure to drop. And yesterday in 100 degree heat and fully loaded with fuel, a passenger, full smoke tank, and about 8lbs of stuff from Aircraft Spruce in the back, I didn't do any aerobatics at all, but the pressure dropped into the high 50's by the time I climbed out to 3000ft.
What is going on?? I have the Raven full inverted oil system, inverted fuel, fuel injection, GRT EIS for engine monitoring.
At start up, I'm getting 79psi for oil pressure. By the time I take off and about 10 minutes into the flight, the pressure drops to about 76-77psi. (I'm thinking this is probably ok as the oil warms up, the viscosity changes and pressure drops). A few more minutes into the flight and it drops to about 74-75psi. As soon as I start doing aerobatics, it drops into the mid to high 60's. Negative Gs drop it much more quickly. Going back to positive G regains some of the lost pressure, but not much. Hard positive Gs also reduce pressure a lot. For example a hard 5G pull to a 45 upline or vertical upline will drop my pressure by about 5psi immediately. If I stop doing aerobatics, and fly level for a few minutes, the pressures come back up by a few psi, but never get back into the 70's. At it's lowest point, it's showing about 54psi (my alarm goes off at 55psi). If I pull the throttle way back (to about 2100rpm), point the nose slightly down, I'll regain about 2psi. Level flying back to the airport and the pressures will very slowly get back up to the high 60s/ low 70s by the time I'm turning final. Back on the ground, I'm back up to about 73psi. On other flights, it never even gets back into the 70's.
But I don't need to do aerobatics for the oil pressure to drop. Even "hard flying" (pulling 3G-4G turns, hard pull to 45 upline, hard push to 45 downline, etc.), or aggressive climb will cause pressure to drop. And yesterday in 100 degree heat and fully loaded with fuel, a passenger, full smoke tank, and about 8lbs of stuff from Aircraft Spruce in the back, I didn't do any aerobatics at all, but the pressure dropped into the high 50's by the time I climbed out to 3000ft.
What is going on?? I have the Raven full inverted oil system, inverted fuel, fuel injection, GRT EIS for engine monitoring.