fl-mike
Well Known Member
Oil Pressure and Question for the Experts - Resolved
New Titan IOX-370 on an RV-8, Titan cold air sump, Hartzell constant speed prop, large 20006A oil cooler on showplanes mount, piston squirters.
Breaking it in on Philips M 20w50XC. Right at ten hours now. I started with six quarts, and added a quart when it was down a half quart or so. I drained it today, and got exactly four quarts out of the sump. So, I'm assuming that the cooler and filter are holding a bit.
Not happy with the oil pressure (since first flight and full oil). It doesn't seem to be regulating well, and is lower than I'm used to. I've turned in the bypass ball spring screw a bunch, checked the ball valve seat, replaced the ball and spring. No change. Checked the screen, all good. It is within Lycoming "good" range, but my old engine was pretty rock solid at 80 until low RPM. I'm flirting with "too high" at cold takeoff power, and then it drops off as it heats up to 60psi or so.
The old plane (Mattituck TMX-0360) never saw below 64 PSI and typically mid 70's at short final , mid to high 80's in cruise. Low 90's on climb out.
I notice that when I pull some G, the pressure comes up about 20 psi (to 80) and the oil temp immediately falls. See attached plot. Two G turn at timestamp 13:14
Is it possible I'm un-porting the pickup in normal flight and starving the pump? Not enough oil in the sump? Pulling some G puts more oil at the pickup? I don't know what a Titan cold air sump looks like inside.
Right now I'm planning on adding a couple quarts and see what happens. I just hate to have it all end up on the belly.
Mahlon, are you out there? Need some expert advice.
Thanks
New Titan IOX-370 on an RV-8, Titan cold air sump, Hartzell constant speed prop, large 20006A oil cooler on showplanes mount, piston squirters.
Breaking it in on Philips M 20w50XC. Right at ten hours now. I started with six quarts, and added a quart when it was down a half quart or so. I drained it today, and got exactly four quarts out of the sump. So, I'm assuming that the cooler and filter are holding a bit.
Not happy with the oil pressure (since first flight and full oil). It doesn't seem to be regulating well, and is lower than I'm used to. I've turned in the bypass ball spring screw a bunch, checked the ball valve seat, replaced the ball and spring. No change. Checked the screen, all good. It is within Lycoming "good" range, but my old engine was pretty rock solid at 80 until low RPM. I'm flirting with "too high" at cold takeoff power, and then it drops off as it heats up to 60psi or so.
The old plane (Mattituck TMX-0360) never saw below 64 PSI and typically mid 70's at short final , mid to high 80's in cruise. Low 90's on climb out.
I notice that when I pull some G, the pressure comes up about 20 psi (to 80) and the oil temp immediately falls. See attached plot. Two G turn at timestamp 13:14
Is it possible I'm un-porting the pickup in normal flight and starving the pump? Not enough oil in the sump? Pulling some G puts more oil at the pickup? I don't know what a Titan cold air sump looks like inside.
Right now I'm planning on adding a couple quarts and see what happens. I just hate to have it all end up on the belly.
Mahlon, are you out there? Need some expert advice.
Thanks
Attachments
Last edited: