What is the current thinking on ring gap spacing around the periphery of the piston?
I learnt the traditional method of 120° (for 3 rings), but am reconsidering. My Toyota Landcruiser book recommends 180°, i.e., gaps in first and third rings in line. Landcruisers routinely run 500,000 km between overhauls.
This makes sense to me when I think about it, giving a longer (more torturous) path for gas to escape down the piston.
On the other hand, there is a school of thought which claims that most blow-by is past (or behind) the rings, not via the gaps, so it doesn't make all that much difference. Do the rings auto-rotate in service?
Comments?
Jack (JW²)