Weasel
Well Known Member
I have been doing oil samples on my engine every 100hrs since overhaul and I always have higher than I would have expected lead content in the sample.
Samples are taken with the engine warm and approx. 1/2 way through the oil drain.
Engine is started full rich then when running evenly leaned aggressively (just rich enough to run) until ready for take-off.
Full rich on take-off then leaned in the climb to maintain approx. 200-150 rich of peak.
At the end of climb go to Lean of peak for the rest of the flight including descent, landing, and taxi.
Compression is ~75-78/80 on all cyls. bore scope inspections indicate cyl walls look good.
Does not "seem" to have excessive blow by (normal looking belly).
Blackstone Labs indicate averages for a IO-540c4b5 to be 3645ppm.
Mine range from a low of 5175 to a high of 8043 and not necessarily in a trend.
The only other think I can think of is the fuel pump diaphragm. The fuel pump was new from tempest at the engine overhaul. possibly bad?
![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Samples are taken with the engine warm and approx. 1/2 way through the oil drain.
Engine is started full rich then when running evenly leaned aggressively (just rich enough to run) until ready for take-off.
Full rich on take-off then leaned in the climb to maintain approx. 200-150 rich of peak.
At the end of climb go to Lean of peak for the rest of the flight including descent, landing, and taxi.
Compression is ~75-78/80 on all cyls. bore scope inspections indicate cyl walls look good.
Does not "seem" to have excessive blow by (normal looking belly).
Blackstone Labs indicate averages for a IO-540c4b5 to be 3645ppm.
Mine range from a low of 5175 to a high of 8043 and not necessarily in a trend.
The only other think I can think of is the fuel pump diaphragm. The fuel pump was new from tempest at the engine overhaul. possibly bad?