Forum bmwbike.com

Has anyone experienced problems putting a 3 piece piston oil ring in place. The 3 pieces comprise a wavy piece (oil ring expander) sandwiched between 2 identical rails. The wavy piece goes in first and the rails follow. Anyone who has experienced problems, please tell me about them and or any solutions that you found....like going to a standard one piece oil ring for example!

I found the solution to my problem on the DEVES piston rings WEB page. Although the oil ring I have is slightly different from the one illustrated and the sequence of assembly is not quite the same, here is the proceedure:

Install wavy piece first and make sure the ends but against each other. Place the butted end in line with the piston pin. Next spiral down the first rail and place the gap 90 deg to the piston pin. Then place the second rail at top of groove with gap diametrically opposed to the gap of bottom rail. During the operation make sure the butted ends of the wavy piece stay together so that the wavy piece doesn't slip out under the rails

Looking at the piston connected to the connecting rod on your BMW, you now have a wavy piece butted end at 3 or 9 o'clock, a rail gap at 12 o'clock and the other at 6 o'clock. When aligning the middle and top rings at 120 deg intervals, use the gap of the top rail as the reference gap.