Oil Pressure

[magman]

A bud has a C-120 with C-85.

New Accessory Case due to losing prime.

OP about 45# on initial start but drops to 25 after

15 minutes of running & little Temp increase?

Suggestions?

Thanks

[Robert Lees]

Re: Oil Pressure

Continental Document X-30010 (Overhaul Manual) states on page 12 that for a C85, the oil pressure limits (in psi) are:

Cruise 30-60
Minimum at idle: 10


I must confess that your pal's engine sounds like it's got a problem other than the oil pump, although it seems to still be within limits.

As a comparison, when starting, my C85 goes straight to 55-60 psi, but when the oil is hot (say after a long flight) and I reduce power to descend, it does drop down, eventually to about 15 on short final with the engine at idle.

Hope that helps,
Rob

[Guest]

Re: Oil Pressure

A bud has a C-120 with C-85.

New Accessory Case due to losing prime.

OP about 45# on initial start but drops to 25 after

15 minutes of running & little Temp increase?

Suggestions?

Thanks

Magman,

What RPMs are these pressures at?

Did they check all the clearances for the pump when putting it back together? (there are few of them to check)

Dave

[3Dreaming]

Re: Oil Pressure

I'm not sure about the 85, but a 65 will do that if the case is worn around the cam bearing area. The fix is to send the case halves out to be machined and line bored.

[Guest]

Re: Oil Pressure

Hi Tom, the initial post said "New case" I took that literally but maybe that was a mistake on my part.

[Robert Lees]

Re: Oil Pressure

Not quite, Dave...Magman said "new accessory case" rather than crankcase, to which I think 3Dreamer refers...and 3Dreamer is along my lines, in that there is more to this chap's C120 engine than the accessory case.

Magman: sometimes these things settle down, but I fear your pal may need a phonecall to Divco.

Rob

[magman]

Re: Oil Pressure

Update:

Installed thick washer & Press is 50+.

Thin washer gives 40-47 Full Throttle & 25 Idle.

Not sure if warmed up though.

[Guest]

Re: Oil Pressure

Not quite, Dave...Magman said "new accessory case" rather than crankcase, to which I think 3Dreamer refers...and 3Dreamer is along my lines, in that there is more to this chap's C120 engine than the accessory case.

Magman: sometimes these things settle down, but I fear your pal may need a phonecall to Divco.

Rob

Yep, you are correct Rob, I was thinking new accessory case when I typed it but I see now what Tom was describing, Thanks, Dave.

[Ragwing nut]

Re: Oil Pressure

just because it says new accy case, may not imply brand new, unless docs to prove it. Check all tolerances, the key is idle pressure. If all the tolerances are in spec i it should idle around 30psi, if rear case checks out good, then front cam bearing tolerances are worn out.

[N96337]

Re: Oil Pressure

Don't forget to check the accuracy of the gauge as well.... not uncommon at all to find quite a discrepancy in what they see and what they read!