All - I am in the midst of an annual on my 460h IO-360M1B on my RV-8, and, having never done this before, I decided to boroscope the cylinders. I was surprised to find that the cylinder heads had large patches of multicolored irregularities - some cylinders worse than others - almost like flat patches of material. I dont think that it represents rust as I fly pretty regularly, but I was surprised by the amount of it (unfortunately I couldnt get a picture with this particular scope). The cylinder walls looked good as did the rings.
Does anyone know what this is? I run my engine with aggressive leaning to keep it about 50deg rich of the hottest cylinder and the cht's all run within about 10-20deg of each other. Compressions are all very good (76-80).
Anybody with some grey hair on this subject have any thoughts?
Jon Weiswasser
N898JW
Does anyone know what this is? I run my engine with aggressive leaning to keep it about 50deg rich of the hottest cylinder and the cht's all run within about 10-20deg of each other. Compressions are all very good (76-80).
Anybody with some grey hair on this subject have any thoughts?
Jon Weiswasser
N898JW