Preparing Chrome Cylinders?

[huskihl]

So what you are saying is to just install new rings and run it?

Cylinder in question does show some faint (factory?) abrasion in areas where the piston didn't travel so it looks like there was a little roughness originally to help seat the rings.

You need to make sure that the walls and rings don’t have any glazing. If there’s not a bunch of black all the way around the piston, it’s likely that they are fine. Either way, red scotch Brite removes anything that you need to get a new rings to see well

 

[Mad Professor]

So what you are saying is to just install new rings and run it?

Cylinder in question does show some faint (factory?) abrasion in areas where the piston didn't travel so it looks like there was a little roughness originally to help seat the rings.

I use 320 and 400 wet/dry and just finger sand it.

 

[Breckinridge Elkins]

Funny how some think the aqueous is better. I will tell you if you get the mix wrong it will eat paint and dissolve magnesium.

I think I just learned this the hard way dammit. You know, I only swapped parts washers to make one coworker happy. Now I am stuck with this thing.

 

[Bill G]

I think I just learned this the hard way dammit. You know, I only swapped parts washers to make one coworker happy. Now I am stuck with this thing.

What kind did you get?

 

[Breckinridge Elkins]

We have a contract with Safety Kleen aka Clean Harbors. Its This One

 

[Bill G]

I remember 30 plus years ago when we got a Safety Kleen unit. That was the end of using mineral spirits

 

[stihltech]

You are right I have no experience with new cylinders. At least 1 a month for 42 years. All hand crosshatch for ring seating.
Actually had a customer bring in an 044 that had a new piston with low compression. All checks good
Glazebreaker in the cylinder for a light crosshatch. REMEMBER, we are only breaking the glaze, NOT OVERSIZING! Compression returned due to seating of rings. Saw power returned and idled great. Did no other repairs.

A cylinder and rings have to size to each other. Basic engine service. Has not changed since the beginning.
Maybe I will learn something in my next 40 years.

 

[bwalker]

I was under the impression that Nikasil was a lot harder than chrome.

It is.

 

[lone wolf]

So what you are saying is to just install new rings and run it?

Cylinder in question does show some faint (factory?) abrasion in areas where the piston didn't travel so it looks like there was a little roughness originally to help seat the rings.

Dont worry about it it will work as long as the cylinder bore isnt scored all up and looks good run it.

 

[bwalker]

You are right I have no experience with new cylinders. At least 1 a month for 42 years. All hand crosshatch for ring seating.
Actually had a customer bring in an 044 that had a new piston with low compression. All checks good
Glazebreaker in the cylinder for a light crosshatch. REMEMBER, we are only breaking the glaze, NOT OVERSIZING! Compression returned due to seating of rings. Saw power returned and idled great. Did no other repairs.

A cylinder and rings have to size to each other. Basic engine service. Has not changed since the beginning.
Maybe I will learn something in my next 40 years.

Exactly.
I use an appropriate sized ball hone AKA dingle berry hone to deglaze the cylinder and do so briefly.
The main thing to consider for proper ring seating is to not baby the saw with new rings. Bring it up to operating temp and then load the hell out of it.
The guys that idle the saw in the hopes of "heat cycling" and other such none sense are shooting themselves in the foot.

 

[bwalker]

Our new solvent tank is "aqueous" I miss the old oil based one.

I grew up in my grandfathers machine shop. We used Toluol in the parts washer, which was a mixture of Toluene and Xylene IIRC.
Never seen any other product work as well.

 

[Gord404]

It is, and honing it is pointless. If you have an abrasive that will cut it, you'll cut right through it. It's very thin.

I agree

 

[bwalker]

OEM Stihl, no crosshatch.

Crosshatch was for cast iron lined cylinders, those would wear in with the rings.

An aggressive crosshatch on a plated cylinder will wear out the rings


View attachment 1104467

Most plated cylinders I have dealt with have crosshatch when new.

 

[bwalker]

I agree

It requires diamond hones to hone it to size from the factory.

 

[SteveSr]

So it appears that the cylinder plating and the ring material (and finishing) are a compatible set regarding hardness so that one won't "wear out" the other prematurely.

Nikasil is a combination of nickel and silicon carbide. The nickel holds the silicon carbide in place. The advantages of nikasil is that it holds oil well and is less britle than chrome. However it doesn't handle fuel with sulfur in it which is no longer an issue.

Nikasil is slightly magnetic and can be used to determine the plating on a cylinder. I tried this on an old Mahle cylinder from an 026 and it is magnetic whereas the cylinder in question is not and is likely chrome.

The main performance issue with chrome is that it doesn't hold an oil film well, at least not as good as Nikasil. This may be why these engines are sometimes specified to run 40:1.

Here are a few more tidbits:

https://en.wikipedia.org/wiki/Nikasil

 

[Mad Professor]

So it appears that the cylinder plating and the ring material (and finishing) are a compatible set regarding hardness so that one won't "wear out" the other prematurely.

Nikasil is a combination of nickel and silicon carbide. The nickel holds the silicon carbide in place. The advantages of nikasil is that it holds oil well and is less britle than chrome. However it doesn't handle fuel with sulfur in it which is no longer an issue.

Nikasil is slightly magnetic and can be used to determine the plating on a cylinder. I tried this on an old Mahle cylinder from an 026 and it is magnetic whereas the cylinder in question is not and is likely chrome.

The main performance issue with chrome is that it doesn't hold an oil film well, at least not as good as Nikasil. This may be why these engines are sometimes specified to run 40:1.

Here are a few more tidbits:

https://en.wikipedia.org/wiki/Nikasil

I have reservations of using Wikipedia as a source of information. Anybody can post information and it is biased.

That said all the search engines lead straight there.......

 

[bwalker]

I have reservations of using Wikipedia as a source of information. Anybody can post information and it is biased.

That said all the search engines lead straight there.......

The referenced post is spot on.

 

[JR Hill]

Get the dingleberry hone, the hatch pattern is much better compared to hand sanding plus there is a lesser chance of sanding the cylinder out of round or going through the plating

A using that 'dingle berry' on a two cycle will not play nice with the ports. Even hand sanding is going to work on edges. Chrome is exceptionally hard - harder than any aluminum oxide etc. If you manage to cross hatch the chrome it will work to your disadvantage. This is one of those things where you are over doing it to your disadvantage.

 

[cookies]

A using that 'dingle berry' on a two cycle will not play nice with the ports. Even hand sanding is going to work on edges. Chrome is exceptionally hard - harder than any aluminum oxide etc. If you manage to cross hatch the chrome it will work to your disadvantage. This is one of those things where you are over doing it to your disadvantage.

Pro porters have been using them for decades

 

[bwalker]

A using that 'dingle berry' on a two cycle will not play nice with the ports. Even hand sanding is going to work on edges. Chrome is exceptionally hard - harder than any aluminum oxide etc. If you manage to cross hatch the chrome it will work to your disadvantage. This is one of those things where you are over doing it to your disadvantage.

That's nonsense.
Eric Gorr who worked with US chrome actually recommended their use.
Chrome isn't that hard either. Nothing like Nikisil which is silicon carbide in a Nickel matrix.