ORIGINAL: MTK
ORIGINAL: AJsToyz
Wondering why the piston was made with three ring grooves? I know the Saito glow four stroke only uses one ring, not sure about the gas, or the other companies. The NGH has two compression rings and an oil ring groove? Was this piston made for this engine or was the displacement made around the piston?
Andy
I'd hazard a guess...weight savings?? (TIC)
My guess is they was going too use 3 rings like a lot of large 4 cycle engines use but found out that 3 rings made too much drag...and probably 2 rings worked better or good enough.
I bet if one Frank Bowman ring was used....one ring would be fine. If 2cycle oil is mixed in the gas for lubrication...you want oil to by-pass the piston and lube the bottom end. With 3 rings oil may not collect where it should. Just a wild Idea !