a properly honed cylinder does not need bon ami or and other crap dumped down the intake!
that bon ami story goes way back, and i suspect it was some dumb ass that tried it and it help a horribly glazed cylinder, but i doubt it.
so for the love of all that is mechanical, put nothing in the cylinder but clean air and properly injected fuel.
if an engine is glazed up and the rings are not seating,, take it apart and do it right,, rehone and replace the rings.
if anyone insists on using sand (bon ami) all you will do is prematurely wear out parts and it will become trapped in the ring lands and continue to wear
for a very long time.
bon ami was never a standard operating procedure with any engine that i am aware of, chrome rings or not.
the proper way to break in any of these engines is to hone properly, clean till a white paper towel with motor oil comes out without any gray color, fit the rings properly
put it together, start it and get it up to temp and under load asap,, no extended idle times,, if you cannot get it under at least 50% load within the first few minutes of startup,, don't start it!
get it warmed up, up to operating rpm and under load, this is the minimum that should be done.
stories about bon ami, edta , and over unity are like finger nails on a black board to me.
as a fellow mechanic used to say "it makes me feel like i have athletes feet on my tounge"
the moral to this tirade (or is it tyrade?) is,, cleanliness is truely next to godliness when it comes to engines.
if you want to test the theory of useing bon ami or ajax or whatever:
take a piece of glass and lay it down on a bench,, then dip your index finger in a drop of motor oil
sprinkle some of your ajax or bon ami on the drop of oil
and then rub in a small quarter size spot on the glass for about 60 seconds
then clean the glass,,, you will see the glass is now dull and milky looking from being worn and abraided
then consider that their is not one single part in your engine that approaches the hardness of glass, and that it will be running for much longer than 60 seconds!
when it comes to cleaning the cylinder bore,, i have written on this before and will do it again for the newcomers here.
cleaning with solvent such as carb cleaner or brake cleaner does nothing to remove the fine abrasives,, all it removes is the oil
so after you use your favorite solvent use hot soapy water and thoroughly scour out the bore and if it is a sleeve inside and out.
rinse it and dry it well, then using either a clean white linen not a terrycloth towel which leave lint, or a white paper towel
oil the bore well and wipe with the white towel, keep oiling and wiping until a clean towel comes out with not other color but the honey color of the oil
i like atf because it will come out bright red when it is truely clean. then and only then is it suitable for use.
the pistons should be done the same, inside and out, and also the rings.
any grit will find its way into the ringlands and work to lap the cylinder and cause premature wear or damage.
if you follow these guidelines your engine will break in quickly and will live alot longer, i have seen twice to three times the lifespan.
btw,, be sure to clean your ring compressor as well, even if it is a new one right out of the blister pack.
bob g
