aluminum lawn mower engine bore coating?

[r7000]

for the aluminum lawn mower engines of today that do not have an iron bore,
such as a honda gcv200, what / how do they coat the aluminum cylinder bore with?

is it nikisil (i.e. silicon carbide) ?

Is it, does it need to be, different than the coatings used on 2-stroke cylinder bores?

Is it correct to say a good chainsaw, like a Stihl, that has a cylinder which I believe is (or was) made by Mahle was SiC (nikasil) ?

thanks.

 

[Steve]

for the aluminum lawn mower engines of today that do not have an iron bore,
such as a honda gcv200, what / how do they coat the aluminum cylinder bore with?

is it nikisil (i.e. silicon carbide) ?


Is it, does it need to be, different than the coatings used on 2-stroke cylinder bores?

Is it correct to say a good chainsaw, like a Stihl, that has a cylinder which I believe is (or was) made by Mahle was SiC (nikasil) ?

thanks.

They are unplated like the cool bore Briggs engines of yesterday. Don't worry, Mercedes uses aluminum bores in most their gasoline engines too. The Aluminum uses a very high silicon content and after it is bored and honed to size it is polished with a silicon paste to treat the metal.

McCulloch did and poulan still uses an unplated aluminum cylinder with a chromed piston.

 

[FergusonTO35]

The unplated cylinders don't hold compression as long as the coated ones, but they are certainly cheap enough. The piston and cylinder for my Poulan weedeater was only $45.00 from the Husky dealer.

 

[farminkarman]

for the aluminum lawn mower engines of today that do not have an iron bore,
such as a honda gcv200, what / how do they coat the aluminum cylinder bore with?

is it nikisil (i.e. silicon carbide) ?

Is it, does it need to be, different than the coatings used on 2-stroke cylinder bores?

Is it correct to say a good chainsaw, like a Stihl, that has a cylinder which I believe is (or was) made by Mahle was SiC (nikasil) ?

thanks.

I realize your question was asked a while ago, and I'm not sure it was really answered. Here is the process that is used by B&S and by Honda on their lower quality engines:

IN A PROCESS FOR PROVIDING AN ALUMINUMSILICON HYPEREUTECTIC ALLOY CYLINDER, THE IMPROVEMENTS COMPRISING THE STEPS OF: MACHINING AND FINISHING THE SLIDING SURFACE OF SAID CYLINDER TO A GIVEN DIMENSION SO THAT FINISHED PRIMARY CRYSTAL GRAINS OF SILICON CLEARLY APPEAR ON SAID SLIDING SURFACE, SUBJECTING SAID FINISHED SURFACE TO PICKLING ACTIVATING TREATMENT TO REMOVE EUTECTIC ALUMINUM SOLID SOLUTION SURROUNDING THE PRIMARY CRYSTAL GRAINS OF SILICON TO A GIVEN DEPTH IN THE MANNER THAT SAID PRIMARY CRYSTAL GRAINS OF SILICON ARE NOT SUBSTANTIALLY CORRODED AND ARE LEFT INTACT

As for Stihl, Husqvarna, Echo, etc. their OEM cylinders are coated with Nikasil. And I should add that any of the Honda GX engines have cast iron cylinder sleeves (as do most if not all the Chondas).

 

[Al Smith]

Depends on how old and brand the engine is . Those old Tecumseh engines that some models of Craftsman mowers looked like bare aluminum .Most of the Briggs were either iron or plating I suppose chrome . As far as I know the 8 HP vert engines came with plating and no bushings for the mains ,just the aluminum block .Next up iron cylinder with brass bushings IC engines ,next iron cylinders ball bearings dubbed the IC industrial version . .
Now then the Briggs pan cakes 14-16-18 HP used on riding mowers .I should know but forgot but assume chrome ,splash lubricated left engine side .Ran very long blowing grass down hill they will hang from oil starvation and it breaks both connecting rods like they were tooth picks .Fact I have three of them in my shop .junk .

 

[AVB]

Briggs aluminum bore engines are just that plain aluminum.

 

[FergusonTO35]

I'm always amazed at how long those cheap B&S engines can go if you actually take care of them and don't make it a habit to mow rocks. I think I'm going to pick up a third push mower for the fleet this spring.

 

[AVB]

I'm always amazed at how long those cheap B&S engines can go if you actually take care of them and don't make it a habit to mow rocks. I think I'm going to pick up a third push mower for the fleet this spring.

Yes they last good while when well maintained. The problem most homeowners take better care their beer cans than the equipment.

Tree roots is the one that takes out a lot of walk behinds engines too. The Aussies has a system that is a lot better than the bar blade system we use here in the US. It is swing back system like our bush hog rotary mowers use.

 

[Al Smith]

Those Briggs engines especially the flatheads have been around a long time .Being somewhat of a pack rat I have a bunch of them and some are iron engines which are very old .Fact I think the Kohler 8 HP I have on a Case asphalt roller is an iron engine . I've got a Jaeger water pump with a Wisconsin single 3HP with an iron block and an aluminum head I think came over on the Mayflower .Talk about heavy .Needless to say I got heap big piles of old junk .I doubt seriously if the newer push rod OHV Briggs engines will ever last as long as the old flat heads . I've got two of those also one on a pressure washer and one on a leaf vacuum .

 

[Al Smith]

Tree roots are a problem ,rocks are worse .Hit a good stout rock with a push mower it can break the crankshaft like a tooth pick .With a rider it can knock the spindle out .My Toro zero turn has heavy spindles like a Dixie Chopper .I'd hate to have to replace those spindles on it ,costly .

 

[Al Smith]

McCulloch did and poulan still uses an unplated aluminum cylinder with a chromed piston.

I'm not certain which McCulloch you are referring to but I've never seen one .What might appear to be on the piston ,dull metalic finish ,is a process called TIN plating .Not tin like a tin can .It's done through a chemical bath type of transfer unlike electro plating .Two reasons ,it slows down galvanic action between metals plus oil sticks to it better than bare aluminum . It was a standard used on automotive type pistons before the present teflon type coatings were used .As far as bare blocks it might on a mini mac which is a POS saw but none other I'm aware of .I'll check though because I have blocks laying around from mini's to 700 - 850 's It's only a question of where they might be hiding .

 

[AVB]

The Mcculloch Wildcat and MacCat I owned had plated cylinders. They lasted me 20 yrs until I finally wore them out.

The Poulan 42CC clamshell had two version one with plan cylinder and a NCC piston and one with NCC Cylinder and plain piston. My personal Poulan 4218AVX originally had the plain cylinder NCC piston then while it was on load it got straight gassed. I rebuilt it using the NCC cylinder and plain piston.

NCC = Nickel Ceramic Coating

And no you can not put NCC parts in the same setup. I checked when rebuilding the saw.

 

[Al Smith]

When Chevy had a brain fart and came out with that POS Vega that engine didn't do well .Wore the aluminum cylinders out .One of those fill up with oil and check the gas deals .Good mosquito fogger though .
At the same time Ford came out with the Pinto and you couldn't wear that engine out--iron cylinder . BTW my name is on the very last of those 2.3 liter engines ever built .