Originally Posted by Chip Stevens
Wallowa. There is always some blow by. One can even hear it when they do a compression check on an aircraft engine. My mechanic rockes the prop back and forth to get as high a reading as he can get. The last check averaged 76lbs with 90 lbs input. The manufacture says it can go down to 60 lbs as long as it is not going past a valve. The point I'm trying to make is blow by is greater then most realize. While I'm pontificating, there are some that feel the loss between the piston and the rings is larger then the rings and the cylinder walls. that would mean seating rings also includes the surfaces between the rings and the piston as well as the rings and the cylinder walls. chip
You're correct Chip.
Good piston, piston ring and cylinder design work together to provide long lasting service under extreme heat with high friction and gas pressures. The boxer engine uses high quality pistons and rings from Mahle, a world class manufacturer (when next watching NASCAR on SPEED, note the Mahle fender sticker on your favorite car).
Blow-by is inevitable. If the fuel is wet, then you're going to load your engine oil with moisture increasing the potential for the formation of acids. There are many stations that turn over their fuels slowly, maintain their equipment poorly and dispense wet fuel unknowingly, I fuel only at high volume stations that I trust. If you're travelling, truck stops typically have high gasoline turnover and keep their equipment in good working order. Of course, you can always ask the attendant behind the register. I once asked the local station clerk, "When did you get your last fuel delivery" When I heard two weeks ago, I rode on to another station. Motor fuel does sour with age so, use caution.
If you get water in your crankcase, change the oil and filter ASAP.