Husqvarna 564xp porting

[Jamie D]

That's the million dollar question with Gilardoni jugs, I only hear negative things about them.

It's a problem for band machining some cylinders are only suitable for a base cut

 

[Tor R]

It's a problem for band machining some cylinders are only suitable for a base cut

Good point, never thought about that

 

[mainer_in_ak]

Did any of the saw porters on here cringe when they saw the finish of those 564 cylinder ports? Ewwww.

What is the weight on that ridiculously tall piston?

 

[Kongpils]

Did any of the saw porters on here cringe when they saw the finish of those 564 cylinder ports? Ewwww.

What is the weight on that ridiculously tall piston?

I did not weigh the piston. But should remember to do so as soon another one shows up. Yes the finish in the ports are very rough.

 

[MG2186]

I did not weigh the piston. But should remember to do so as soon another one shows up. Yes the finish in the ports are very rough.

All the new Husky saws are that way. Doesn’t seem to hurt their performance

 

[huskihl]

592 is the best running 90cc saw to ever hit the market and the ports are all rough like that. What glitters isn’t always gold

 

[Tor R]

I don't care if the ports are rough, the only thing that matters is that it doesn't cause unnecessary wear on the piston & rings.

 

[EFSM]

Did any of the saw porters on here cringe when they saw the finish of those 564 cylinder ports? Ewwww.

What is the weight on that ridiculously tall piston?

I’m also not a huge fan of the really deep honing marks, but I suppose nitpicking isn’t warranted unless they actually have some teething problems.

 

[mainer_in_ak]

I’m also not a huge fan of the really deep honing marks, but I suppose nitpicking isn’t warranted unless they actually have some teething problems.

Yep, in addition to the ROUGH ports, finish of the bore looks crude. Its almost like a Chinese clone saw cylinder.

 

[bwalker]

Did any of the saw porters on here cringe when they saw the finish of those 564 cylinder ports? Ewwww.

What is the weight on that ridiculously tall piston?

It doesn't matter. Port finish has no effect on unsteady gas flow in a duct. This is because the area next to the surface sees little movement.
The only port I want with a fine finish is the exhaust port for the purpose of limiting carbon buildup.
The piston is no doubt on the heavy side. Strato pistons always are.
I do wish it had a Mahle cylinder.

 

[bwalker]

I’m also not a huge fan of the really deep honing marks, but I suppose nitpicking isn’t warranted unless they actually have some teething problems.

I am. Hold more oil and break in quicker.

 

[EFSM]

I am. Hold more oil and break in quicker.

Maybe so, although I’d rather have the machining marks on the piston doing the oil holding. Also, a quick break in means higher rates of ring wear. I have seen the worst ring wear in Husqvarna products.

 

[bwalker]

Maybe so, although I’d rather have the machining marks on the piston doing the oil holding. Also, a quick break in means higher rates of ring wear. I have seen the worst ring wear in Husqvarna products.

The peaks of the cross hatch are quickly worn down( which is why stringing out break in is not a good thing). After that point wear is no more rapid than with any other finish. Having both the cylinder and piston hold oil is a good thing.
When you send a bike cylinder in for replating from a reputable company they come back looking like the pictures here. Factory cr500 cylinders look exactly like this as well. Its actually pretty normal for both cast iron and plated two cycle cylinders.
I havent seen abnormal ring wear from Husky, Stihl, or Redmax.

 

[Outback]

The ring isn't rubbing across the piston under the pressure of combustion. Its being forced out against the cylinder walls. Regardless of the smoothness of your piston ring wear is faster on cylinders with no cross hatching.

 

[bwalker]

The ring isn't rubbing across the piston under the pressure of combustion. Its being forced out against the cylinder walls. Regardless of the smoothness of your piston ring wear is faster on cylinders with no cross hatching.

Yes, because they hold less oil and have more bearing area on the ring.
Regardless this is sorting fly shat from pepper. Saws have such a low output that they dont wear rings fast at all. For instance a 250cc dirt bike will toast rings in 100 or less hours. A 125cc less than half that. Even a cr500 which makes peak power at 6500rpm won't go near 500 hours. Most saws will easily exceed this with some going well over 1000 hours.
When I logged I would run ported or non ported with a muffler mod 372xpg's for an estimated 800 hours in a year. I would re-ring and run them for a bit longer then religate them to backup duty. Never had to replace pistons, never lost compression and never had any engine failures doing this. Always ran 32:1 with good oil. I gave one of my ported XPG's to a friend back some around 2007 and he is still cutting firewood with it. I also fooled around with a Dolmar 7900 and Stihll 440's same story with those.

 

[jurchybald]

The owner is on firewood duty these days so expect he will tell soon.

What's the verdict? Mine is on the way.

 

[EFSM]

The peaks of the cross hatch are quickly worn down( which is why stringing out break in is not a good thing). After that point wear is no more rapid than with any other finish. Having both the cylinder and piston hold oil is a good thing.
When you send a bike cylinder in for replating from a reputable company they come back looking like the pictures here. Factory cr500 cylinders look exactly like this as well. Its actually pretty normal for both cast iron and plated two cycle cylinders.
I havent seen abnormal ring wear from Husky, Stihl, or Redmax.

It’s hard to tell from these pictures, but I’d say the honing is rougher in this 564 cylinder than average. You’re right in saying that crosshatching is important; the point I was trying to make is that I’d rather see more numerous fine crosshatching rather than fewer deep crosshatching marks.

The ring and especially the piston wear I see on Husqvarnas is better attributed to the low wrist pin position on newer strato engines. They’re not the only manufacturer to use tall pistons, but for some reason I see a higher rate of piston wear on them than other brands.

 

[Kongpils]

What's the verdict? Mine is on the way.

He likes it very much. Easy starting and smooth power.

 

[bwalker]

It’s hard to tell from these pictures, but I’d say the honing is rougher in this 564 cylinder than average. You’re right in saying that crosshatching is important; the point I was trying to make is that I’d rather see more numerous fine crosshatching rather than fewer deep crosshatching marks.

The ring and especially the piston wear I see on Husqvarnas is better attributed to the low wrist pin position on newer strato engines. They’re not the only manufacturer to use tall pistons, but for some reason I see a higher rate of piston wear on them than other brands.

I would think/hope the company supplying the cylinder knows what the are doing.
In regards to your comment on Husky strato saws and premature ring wear. You very well be right. I dont put enough hours on them anymore. It will never become an issue for me with my limited usage.
I will say that I do have alot of expiereance with very high hour Husky and redmax blowers which use very similar piston designs and never noted anytging weird ring wear wise. A blower isnt a saw though and not close.

 

[EFSM]

I would think/hope the company supplying the cylinder knows what the are doing.

I agree, but competence is so lacking in today’s world that I’ve become somewhat cynical.