redbelliedjet
Well-Known Member
- Joined
- Jan 20, 2009
- Messages
- 85
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Hello all,
I would like to get advice on an ongoing issue with my J5's C-85. The engine has always liked to run hot in the summers and mid range in the winters (Cali winters, that is). Typically it will top out about 115f over ambient at top of climb. High oil px has never been one of this motor's strong suits, but it could always barely pull off 30psi at hot cruise and 15 to 20 at idle. This summer it is still running 115f above, but the oil px is now around 27ish and 13-14 at idle. I was in formation with another j-5 and an L-4 when the air temp was around 95f, and both of the other airplanes also have c-85's. Mine was running 20f hotter and 12 psi lower than the other two engines. I decided that this may just be the personality of this motor and was looking to install an oil cooler. The oil analysis has always been good except for a slight rise in iron noted on the last check. I decided to run another analysis to make sure that I was not just putting a bandaid on an internal engine problem. The analysis came back having 3 1/2 times the average level of iron, almost twice the amount of aluminium, and tin and copper being slightly above average. The eleven hours that was on the oil was flown within a weeks time of the sample, so corrosion should not be the culprate. This is a pretty sharp spike for this motor which alway had iron numbers well below average.
Any ideas? Could this be something simple, or a bearing/shaft issue? BTW, compressions are all in the upper 70s and the engine has 390 smoh by Magnum Engines (about 9 years ago).
Thanks in advance for any advice. Any one know of a really good c series builder?
Cheers,
Dan
I would like to get advice on an ongoing issue with my J5's C-85. The engine has always liked to run hot in the summers and mid range in the winters (Cali winters, that is). Typically it will top out about 115f over ambient at top of climb. High oil px has never been one of this motor's strong suits, but it could always barely pull off 30psi at hot cruise and 15 to 20 at idle. This summer it is still running 115f above, but the oil px is now around 27ish and 13-14 at idle. I was in formation with another j-5 and an L-4 when the air temp was around 95f, and both of the other airplanes also have c-85's. Mine was running 20f hotter and 12 psi lower than the other two engines. I decided that this may just be the personality of this motor and was looking to install an oil cooler. The oil analysis has always been good except for a slight rise in iron noted on the last check. I decided to run another analysis to make sure that I was not just putting a bandaid on an internal engine problem. The analysis came back having 3 1/2 times the average level of iron, almost twice the amount of aluminium, and tin and copper being slightly above average. The eleven hours that was on the oil was flown within a weeks time of the sample, so corrosion should not be the culprate. This is a pretty sharp spike for this motor which alway had iron numbers well below average.
Any ideas? Could this be something simple, or a bearing/shaft issue? BTW, compressions are all in the upper 70s and the engine has 390 smoh by Magnum Engines (about 9 years ago).
Thanks in advance for any advice. Any one know of a really good c series builder?
Cheers,
Dan
