Thanks Gadge, in those days at least, Briggs' engineers knew what they were doing, so it appears that the chrome plated rings can be used in aluminium bores. Did the chrome plated ring sets come with chrome plated steel rail oil rings?
Yep, they have the 3-piece oil rings, and as I recall it the rails were chrome plated.
It appears that the standard ringset oil ring type for this model is a two-piece cast iron, with the internal spring expander.
I don't know how the ring pressure from those steel rail rings with expander, compares with the pressure from cast iron one piece oil rings. If the pressure is the same, it should work.
Yep, so long as the ring tension is appropriate to the design, both will function equally well.
