Piston Ring Positioning and Ring Gaps for the 410cc BB kit

[sam2019]

The first ring is the silvery looking one. The up side has a stamped in marker "TOP 1" - which indicates it is the first ring (from above) and the printed side is UP.
The second ring is black and also has some marker: "TOP 2". Same logic applies: Its the second ring from the top and the imprint is showing UP wards.
The oil ring consists of 3 pieces, the top and bottom are interchangeable and can be placed either side up with the wavy part in the middle.

When positioning the rings make sure the open ends do not overlap, best to position them with a ca. 90 degrees offset.

 

[Dool]

10 o'clock and 2 o'clock for the top 2
Oil ring ends need to be over the piston pin so as to away from the oil holes.
Spacer ends face upwards.
IMO.
They are never in that position when I disassemble an engine regardless of where I position them!

 

[sam2019]

Thanx Dool, I forgot to mention the oil ring spacer ends face UPWARDS!
of course during operation the rings will move. The initial position is just a "good start".

 

[sam2019]

Ring Gaps:
3 to 5 thousands of an inch gap per inch of bore.
Top ring should be less than second ring
Measured 1 inch down from the top, meaning: put the ring in the bore and push it down with the piston at least 25mm from the top so that the ring is "square" in the bore (same distance down all round)

13 thou top ring, 16 thou second ring is good

More info here:
https://wossnerpistons.com/pages/4-cycle-ring-end-gap-calculator

 

[Dool]

0.3mm top and 0.4mm second