My freshly rebuilt now has 15 hours in service and I changed the oil and filter. The good news is that the amount of small aluminum flakes is dramatically reduced from the filter pulled at two hours. It seems that the problem is not persisting and was related to the initial break in.
The concern was the chunks of carbon that I found in the drain oil. There were several moderate size chunks of carbon that were found at the bottom of the drain pan. The bigger ones were maybe a 1/16" in diameter. I assume this is from blowby gasses generating heat and coking the oil, presumably in the oil ring cavities. I hadn't been paying much attention to oil temp (no alarms went off and the times that I looked it was 190-200). Today, at 75% cruise, the gauge went yellow and the temps were 218 (90* ambient, but typical of most of my flights).
Is this normal for a new or overhauled engine while breaking in? I have heard that it can take over 20 hours for rings to fully seat and the oil temps will run high untill that happens. Is that typical? My CHT's have been consistently below 400.
The oil is dark and bordering on black.
Larry
The concern was the chunks of carbon that I found in the drain oil. There were several moderate size chunks of carbon that were found at the bottom of the drain pan. The bigger ones were maybe a 1/16" in diameter. I assume this is from blowby gasses generating heat and coking the oil, presumably in the oil ring cavities. I hadn't been paying much attention to oil temp (no alarms went off and the times that I looked it was 190-200). Today, at 75% cruise, the gauge went yellow and the temps were 218 (90* ambient, but typical of most of my flights).
Is this normal for a new or overhauled engine while breaking in? I have heard that it can take over 20 hours for rings to fully seat and the oil temps will run high untill that happens. Is that typical? My CHT's have been consistently below 400.
The oil is dark and bordering on black.
Larry