Just acquired a Lycoming O-290 D2. It came with an inverted oil system that I do not know. Was hoping someone might recognize it and help me to lay out the plumbing, since there were no hoses attached when I got it. Engine has a vertical oil strainer, or would have if the inverted system had not replaced it. Instead of the oil strainer I have a modified oil suction tube with a weighted slider that uncovers slots in the tube when under positive G. This is the same tube that leads up to the oil pump. From there things get hazy. The bottom of the oil suction tube has an AN fitting, that I am assuming connects to the breather line for inverted oil supply. Engine came w/o an air/oil separator, but I feel sure that one is needed. Only other sump fitting appears to be an oil return line with a drain plug fixed in the bottom. If anyone recognizes this system and has schematic of to plumb it I would be very grateful.
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