Duke's 262XP top end

[CJ Brown]

I think it is fairly obvious that there is nothing inherently wrong with either chrome or nikasil plating if done correctly at the factory, and the proper ring(s) used. One thing I found out recently is how hard nikasil plating really is - it is a bear to cut or grind if you want to alter a cylinder. So I would guess the guys who want to port or machine these cylinders will appreciate a chrome plated bore as long as the quality is there.

 

[CR888]

I saw a specs sheet the other day for the new MS400 which stated it had a chrome cylinder. This was not from a Stihl website spec sheet, it was a farm supply type dealer so maybe they got it wrong. But I was interested to see if Stihl was moving away from Nikasil on pro cylinders, they have long used chrome and I thought currently the home/farm models were chrome. Nikasil I think was originally invented by Mercedes Benz for there F1 engine many years ago but they dropped the idea and stopped using it. Albeit it was a great idea that Mahle successfully adopted for many small engine applications. Its good we're talking AM cylinders, there is certainly a place for them in the saw world.

 

[mgr1]

Why is a hydraulic piston rod hard chromed plated and not plated with nicasil?

 

[Wonkydonkey]

My 2c worth on chrome and Nikasil..is...
Chrome needs honing in a cylinder because it hates oil (I guess that’s why it’s used in hydraulic rams etc).
so if a cylinder is not honed very well, with just a little oil present, it may easily get burnt off and excessive wear and seizure could follow.

With the Nikasil it’s oil loving..and holds onto more oil, therefore less wear on piston and rings..and lasts longer..
I’ve also read there are a few variations in formula of nikasil, as Nikasil is a trade mark..

I will see if I can find where I read this.. and add a link..

Edit
https://en.m.wikipedia.org/wiki/Nikasil
https://en.m.wikipedia.org/wiki/Alusil

My memory was a bit off, but you get the idea

 

[Wonkydonkey]

So just maybe it’s the sulphur in poor gasoline in some places around the globe is why stihl are going back to chrome

 

[Spike60]

Ports look pretty good, but I still don’t get why the AM can’t get the alignment of the upper and lower correct. All OEM have the entire upper shifted towards the intake side vs the AM which generally have it directly vertically above the lower.

I’d like to see more of the exhaust port. I’d also like to see the chamber and see if it’s plated or not.

Not sure if it’s an illusion, but the base through holes look like they aren’t aligned right? One looks like it’s threaded inside from the bolt rubbing.

Do the tunnels have the flywheel indent in them?

What is the “chrome” plating you speak of? Is it actually just chrome plated, or is it a form of silicon-carbide with more chrome than nickel in it? Do you think it will hold up like Nicasil?

@Spike60 , funny that you mention that the lowers only look larger because they are cleaner. That has been my experience as well. The KS jugs are made of a different alloy than the Mahle. It’s why everyone swears that the KS ND jugs have the biggest tunnels. The KS alloy is brighter and more stain restart than Mahle’s is. The biggest tunnels I’ve seen on a 262 jug are in the Mahle non-decomp, not the KS.

I wish I’d saved the pics I’ve taken over the years of these 262 jugs. They probably have the most differences in any oem jug I’ve played with over the years. Even more than the Stihl 046/460. The KS have square tight uppers whereas the Mahle are always larger and rounder looking.

Thank you both for the thread and the work. It’s great to have another option to go with.

Cylinder bolts were a little tight on the way in. The bolt heads were rubbing against the outside of the cylinder. But the 4 holes do match the gasket and it bolted down fine on the case. Piston didn't feel like it was binding up. But as mentioned, it was pouring rain and we didn't run them. Just mounted them all to get squish numbers.

The port casting does not have an indent or cut to clear the flywheel, but it does clear OK. Think one of my pics shows that. The Farmertec kit didn't clear at all; locked it right up. Could be fixed pretty easy with a file or whatever.

 

[huskihl]

Why is a hydraulic piston rod hard chromed plated and not plated with nicasil?

I believe Nicasil is more porous, or at least has a rougher texture. On a cylinder ram, the chrome is smooth which helps to seal oil leaks, but also it’s used as a rust preventative. I believe it’s much less expensive also

 

[Sawrain]

I would think that’s it.

Looks good.
Rust resistant.
Tough, can be indented without chipping.

Cheaper.
Less hazardous, can somewhat easily be done in house.

And much easier to finish than ceramics/carbides.

 

[drf256]

I saw a specs sheet the other day for the new MS400 which stated it had a chrome cylinder. This was not from a Stihl website spec sheet, it was a farm supply type dealer so maybe they got it wrong. But I was interested to see if Stihl was moving away from Nikasil on pro cylinders, they have long used chrome and I thought currently the home/farm models were chrome. Nikasil I think was originally invented by Mercedes Benz for there F1 engine many years ago but they dropped the idea and stopped using it. Albeit it was a great idea that Mahle successfully adopted for many small engine applications. Its good we're talking AM cylinders, there is certainly a place for them in the saw world.

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

 

[XP_Slinger]

Good stuff gents. Nice looking cylinder! Will be great to have a replacement option for the 262. As Bob said it would be a shame to send that model down the “can’t fix it” road when the OEM cylinders all wear out.

 

[Spike60]

Installed that kit on my 262G, and it's a proper a day for that. Cold, windy, and sideways snow squalls out there. Motivation is slipping boys! I did make about 10 cuts on a 12" ash out back. Runs pretty strong. Plan is/was to run a tank through it this afternoon at home, but ah...…………...maybe a half tank? LOL Would like to run it side by side with a real one. Won't be any data/times/videos and scientific stuff. Just subjective thoughts/opinions. Maybe take some pics. This is more a day for burning wood than cutting it.

 

[82f100swb]

I may need to get my hands on one of these to degree out and port, that is much nicer than the FT cylinder I have, and I really don't want to grind on my OEM cylinder. I will be getting my hands on a 257 that is missing a few parts here shortly and it would be a good test mule so I can leave my baseline "stock" 262 as is.

 

[Spike60]

Little update:

Spent some more time with this saw yesterday. The old G was acting funny the last time I ran it and it turned out that the flywheel seal had let go. New seals on both sides and it's running steady now.

In comparing it to an OEM 262, it's really not that far off. (gasket in the OEM, no gasket for the Duke's kit). You could tell that the OEM had more grunt of course, but the AM kit gave good account of itself. Certainly better than any 257. So, in that context it's a win IMO. With the OEM kits for either the 262 or 257 NLA, this might be the best of the relatively few AM options out there. Way better than having a dead saw sitting under the bench due to a lack of parts to rebuild it, right?

 

[XP_Slinger]

Little update:

Spent some more time with this saw yesterday. The old G was acting funny the last time I ran it and it turned out that the flywheel seal had let go. New seals on both sides and it's running steady now.

In comparing it to an OEM 262, it's really not that far off. (gasket in the OEM, no gasket for the Duke's kit). You could tell that the OEM had more grunt of course, but the AM kit gave good account of itself. Certainly better than any 257. So, in that context it's a win IMO. With the OEM kits for either the 262 or 257 NLA, this might be the best of the relatively few AM options out there. Way better than having a dead saw sitting under the bench due to a lack of parts to rebuild it, right?

Great feedback Bob, thanks for taking the time.

 

[John235]

Thank you. It’s nice to know there’s a worthwhile aftermarket option.

 

[JohnnyBlade]

Ok boys! So i never stopped looking for the StarGry cylinder i said i had since February and i lost 35 lbs just kidding.... but last weekend i was organizing and in a box under a box under another box it appeared!!! I dont think its 262 but now we got to figure out what it is! Bunch of pics for ya. Its 49mm bore with closed ports and a domed squish band. The gunk by the exhaust was/is on there pretty good after 2 days soaking in the parts washer. Similar to what ya see on cut off saws. There is some plating wear on the intake side commom of what u see on cut off saws as well. Now the pics of the plating u can see the bubbling of muratic acid just on the seams, not in the wide area. Kinda weird. Like coloring in the plating changed from wear but only AL is showing at the seams? Anyways ill post pics and we can go from there!

@Duke Thieroff @Spike60

 

[JohnnyBlade]

More pics.

 

[JohnnyBlade]

More pics.

 

[Agent Smith]

@JohnnyBlade
Looks like a 08s/ TS350/ TS360 cylinder

 

[JohnnyBlade]

@JohnnyBlade
Looks like a 08s/ TS350/ TS360 cylinder

I was kinda thinking Stihl. The only saw i found that was 49mm is a 042. I dont know if those wer good saws or cut off saws.