File to fit rings

[Guest Anonymous]

I bought file to fit rings and filed top and 2nd rings to .012 gap. The second ring set comes with an expander. I am wondering if I should use the expander for the 2nd ring - it will make the .012 in gap smaller? The instruction that comes with the ring set was not clear about it - it says if it is 2.0 mm or thicker, then I can use expander? Any clue on what 2.0 mm thickness is?

Thanks.

Jim

[Guest Anonymous]

Jim, the second ring is 2 mm thick. The instructions probably were saying you could not use the expander in an application where the ring groove was too nattow (< 2 mm). I don't know what brand of rings you have there, but I would avoid the expander for the second ring. You have to be concerned with the radial depth as well as the thickness, and the extra drag (tension) is not good.

The expander won't make the gap smaller. The gap won't be made smaller unless the cylinder bore got smaller. The gap will only grow.

File-to-fit rings will require much more break-in wear to take the shape of the bore, as they are made to be round in the next size up.

M10 piston rings are 1.75 / 2.00 / 4.00, which is pretty old fashioned. Modern designs uses smaller, much lighter sizes, which have better performance & don't beat out the ring lands so easily. Note that BMW Motorsports race pistons don't use the second ring.

""I bought file to fit rings and filed top and 2nd rings to .012 gap. The second ring set comes with an expander. I am wondering if I should use the expander for the 2nd ring - it will make the .012 in gap smaller? The instruction that comes with the ring set was not clear about it - it says if it is 2.0 mm or thicker, then I can use expander? Any clue on what 2.0 mm thickness is? ""

[Guest Anonymous]

Thanks - I discarded the expander for 2nd rings. The brand I have is Deves. I am now on the process of putting pistons back on the cylinder block. It would be common sense if I put the gaps of 1st and 2nd rings on the opposite side of each other?

Jim

[Guest Anonymous]

(nt)

[Guest Anonymous]

(nt)