Bore surfaces

[Tony Snyder]

What are the various methods of getting the wear surfaces in the bore of the cylinders?

I am aware of plating, and also know that it used to peel at the exhaust ports on Homelites.

I am aware of plasma vapor deposition but don't know much about it. Is it honed after application?

What about Nikosil, I know very little about that one.

McCulloch used to actually insert mold a cast steel liner into the aluminum cylinders (as did Onon and now many other 4 cycle engine manufacturers)

Do any of the saws just use the plain aluminum surface?

 

[rahtreelimbs]

I do know that some of the less expensive Craftsman saws have a plain aluminum cylinder with no plating. Rich.

 

[bwalker]

Nikasil Is a plateing compound that is trade marked by Mahle. It is basicaly silicon carbide particles imbedded in a nickel matrix. it is applied by electroplating.
Plasma vapor deposition used to be used by Kawasaki on there dirt bike motors under the trade name Kawasaki electro fusion. It is not even close to nikasil in terms of performance and is no longer used by Kaw.

Do any of the saws just use the plain aluminum surface?

I dont think so. Steel rings would eat up a plain aluminum bore in amatter of seconds.

 

[jokers]

What about all those cheap Briggs and Strattons and Tecumsehs out there, I`ve torn apart quite a few and they sure seem to be plain aluminum, not like nikasil that I used to seeing. Russ

 

[bwalker]

What about all those cheap Briggs and Strattons and Tecumsehs out there, I`ve

Dunno, could be plain aluminum. The b&s ive seen had steel sleeves.

 

[tundraotto]

nice going bwalker.... nikasil - the nickel silicate compound still eludes the homeowner most of the time but is one of the better inventions of our lifetime - i only hope that stihls will start using it in their saws.

 

[stihltech]

nikasil

It is listed in the parts now. Nikasil cylinders.
I believe our cylinder are chrome impregnated, not plated.

 

[Greg Carberry]

B&S and Tec. do have plain aluminum in many cheaper engines up to around 12 hp. The piston is plated with some sort of tin coating and thats how it works. I have seen crafstman saws like this also but with a chrome plated piston. It must be cheaper to plate the piston than the cylinder.

 

[bwalker]

only hope that stihls will start using it in their saws.

They do as far as I know.