I'm no expert, but my son Peter and I have taken a couple of Lycomings apart very recently, and both the old high time engine and the old low time engine had a fair bit of sludge caked in the bottom.
I presume both were run on Aeroshell straight weight oil most or all their lives.
The low time engine was running fine on Peter's RV-4. He just dropped the sump to add an inverted oil system. We don't take this to be a problem, as no metal bits were present.
We just wonder about it, should the sump be dropped and inspected at any interval, any comments from the 'old heads' on effects, like more sludge if you don't run an air filter (many old RV-4s don't) or it's just a fact when running ashless dispersant oil?
Will an oil filter prevent sludge build up in the sump?
I presume both were run on Aeroshell straight weight oil most or all their lives.
The low time engine was running fine on Peter's RV-4. He just dropped the sump to add an inverted oil system. We don't take this to be a problem, as no metal bits were present.
We just wonder about it, should the sump be dropped and inspected at any interval, any comments from the 'old heads' on effects, like more sludge if you don't run an air filter (many old RV-4s don't) or it's just a fact when running ashless dispersant oil?
Will an oil filter prevent sludge build up in the sump?