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Workshop => Engine and Bottom End => Topic started by: Mr250sx on January 07, 2014, 09:56:28 AM

Title: Rings for nikasil plated cast iron bore? Anything different?
Post by: Mr250sx on January 07, 2014, 09:56:28 AM

Have a prox cylinder fresh nikasil plated done by millenium and wondered if the rings that came with my wossner piston are correct for it? Thanks

Title: Rings for nikasil plated cast iron bore? Anything different?
Post by: steve250r on January 13, 2014, 07:41:26 PM

Yes, those will be the correct rings.

Title: Rings for nikasil plated cast iron bore? Anything different?
Post by: Tbone07 on January 13, 2014, 09:56:44 PM

The same rings can be used for both bore types

Title: Rings for nikasil plated cast iron bore? Anything different?
Post by: C-Leigh Racing on January 14, 2014, 02:55:20 PM

Those rings & the Wisecos are faced, so will work just fine.

Back in my Briggs days, there were different rings for the aluminum bore blocks & then those for the sleeved type blocks.
I've always wondered, why none of the bike or quad engine never had just a plain aluminum bore like the Briggs. Theres some aluminum bore push mower engines, still running from back in the 60~70s.
Neil

Title: Rings for nikasil plated cast iron bore? Anything different?
Post by: Jerry Hall on January 14, 2014, 04:54:26 PM

The alloy that is used in blocks that have aluminum bores is different than blocks that have plated or sleeved bores.  I do not know what additive Briggs and Straton uses but aluminum bores usually have very small silicon or silicon carbide particles in the aluminum.  The aluminum is the "glue" that holds the microscopic particles just like the nickle holds the small hard particles in the Nikasil plating.  The piston and rings touch some of the "glue" but the hard surface that supports the piston and rings is actually zillions of small hard particles.  

Another way of looking at how aluminum bores works is similar to how concrete works when used for highways.  The cement is the glue that holds the sand and gravel together in concrete.  Tires quickly ware the glue on the surface of the road away between the gravel and rocks.  Eventually the tires are primarily touching only the tough gravel and rocks.

The same thing happens with plated and aluminum bores.  The soft nickel and aluminum wares away during break-in and then the hard silicon and carbide particles become the durable surface that supports the piston and ring load.

Title: Rings for nikasil plated cast iron bore? Anything different?
Post by: SRE on January 14, 2014, 07:46:45 PM

One material for aluminum sleeves is called dispal. It is impregnated aluminum. Never tried it with a two stroke cylinder, sleeved some chevy ls motors with it. Cuts great and hones easy. I think bmw has a aluminum bore production engine