Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

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Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564657 Hello guys,

Sorry my writings in English instead of Swedish, but I'm looking for pop-up pistons for Husq 560 & 550. I couldn't find them anywhere in the internet markets of USA, China or Europe. Only pop-up pistons for old models.

Since these saws are made in Sweden do you know where should I ask for a OEM Pop-Up pistons?

Thank you in advance and greetings from Finland.

-Andrei-



   TS
Husqvarna
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564658 What is a pop Up piston

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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 Firar 10 år som aktiv medlem på skogsforum! 
#564661 Is it from Husqvarna? If so you can order from any dealer. If not its harder...

Pop up pistons is were they take the outer parts of piston a bit and allow cylinder to be lower so they can loose a bit of the volume above TDC, right? Make less volume in a bigger volume...

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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564662
Westra Aros skrev:What is a pop Up piston

It is a piston which increases a squish in a cylinder and as a result you get more torque. I have also a Stihl 261 and I can easily find a pop up piston for it, but for a newer models of Husqvarna I couldn't.

   TS
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564666
Mange skrev:Is it from Husqvarna? If so you can order from any dealer. If not its harder...

Pop up pistons is were they take the outer parts of piston a bit and allow cylinder to be lower so they can loose a bit of the volume above TDC, right? Make less volume in a bigger volume...

Yes, but pop up pistons are more like a normal ones but with a small "metal disc" on top, so if you use only pop up piston no need to correct cylinder ports :smile:

Official dealers offers only normal pistons, at least here in Åbo.

   TS
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564668 http://opeforum.com/threads/husqvarna-5 ... -up.14793/

Thats what I found on Google.

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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564672
vinterrojarn skrev:http://opeforum.com/threads/husqvarna-550xp-pop-up.14793/

Thats what I found on Google.

Ok thank you, but in this case the guy took a metal from a piston and droped a cylinder down, which affects a timing in cylinder and port opening.
For example for Stihl 261 you can find a normal piston with "extra metal disc" on it, which increases a squish and you won't need to drop the cylinder down and modify ports.

It is like a mild tunning with lower effort than porting. Together with muffler mod you can have more torque and use a bigger sprocket, which increases chain speed, etc.

   TS
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 Firar 10 år som aktiv medlem på skogsforum! 
#564768
vinterrojarn skrev:http://opeforum.com/threads/husqvarna-550xp-pop-up.14793/

Thats what I found on Google.

I think thats the way most do it unless you cast piston yourself.
Andrei M3P skrev:Ok thank you, but in this case the guy took a metal from a piston and droped a cylinder down, which affects a timing in cylinder and port opening.
For example for Stihl 261 you can find a normal piston with "extra metal disc" on it, which increases a squish and you won't need to drop the cylinder down and modify ports.

It is like a mild tunning with lower effort than porting. Together with muffler mod you can have more torque and use a bigger sprocket, which increases chain speed, etc.


When lowering cylinder they change the timing ports open and close. Thats part of the trick.
There is a lot of talk about squish and increasing it by removing compressed fuel air mix volume in TDC.
Were do you find 261 pistons with disk on them?
Most do the work themself on original parts.
Just raising compression is not the same as reducing/increasing squish.
Squish volume is the volume above piston at TDC.
Squish band is the clearance needed on the outer parts of piston top so it won't hit the top.
I rather fill the volume there is in TDC more than reduce volume.

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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564793 Probably metal disc is a wrong word for this, I just didn't know how to explain it better, here is the picture

   TS
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564802
Mange skrev:
vinterrojarn skrev:http://opeforum.com/threads/husqvarna-550xp-pop-up.14793/

Thats what I found on Google.

I think thats the way most do it unless you cast piston yourself.
Andrei M3P skrev:Ok thank you, but in this case the guy took a metal from a piston and droped a cylinder down, which affects a timing in cylinder and port opening.
For example for Stihl 261 you can find a normal piston with "extra metal disc" on it, which increases a squish and you won't need to drop the cylinder down and modify ports.

It is like a mild tunning with lower effort than porting. Together with muffler mod you can have more torque and use a bigger sprocket, which increases chain speed, etc.


When lowering cylinder they change the timing ports open and close. Thats part of the trick.
There is a lot of talk about squish and increasing it by removing compressed fuel air mix volume in TDC.
Were do you find 261 pistons with disk on them?
Most do the work themself on original parts.
Just raising compression is not the same as reducing/increasing squish.
Squish volume is the volume above piston at TDC.
Squish band is the clearance needed on the outer parts of piston top so it won't hit the top.
I rather fill the volume there is in TDC more than reduce volume.


With pop up piston, you don't need to touch ports and piston edges and it still will increase compression, because of extra metal volume "AKA disc" on top of it.

The reason I don't want to drop cylinder is because when you do it, the explosion in the chamber doesn't spread on the whole surface of the piston but concentrates in the center of piston. It is because piston edges are too close to the cylinder top, so the center of the piston suffers more pressure and with time it wears down faster.

Of my mind, for more compression, in time of explosion is better to decrease volume in the center of chamber not at the edges, so the power will spread all over the piston, as the chamber and pistons are designed.

   TS
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 Firar 10 år som aktiv medlem på skogsforum! 
#564823 If it is explosions things go kaboom ansd is no more. Its uncontrolled.
The thing that happen after spark is a flame front that expand in volume. It is very controlled and cumbustion chamber, sparks position, flame, expansion is all very controlled.

Increased compression can be done in more than one way. Not just decreased volumes in TDC.

Once in a while I get to compare seeral identical saws. I often talk about a time I had several husqvarna 44 to play with.
All original, all performed different and had different settings and performance.
Same cc though...

There is a lot that can be done to a saw before you get going on mashining parts.

All parts ox engkne create a configuration. Single changes made affect it, but multiple smaller changes affect it more.

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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564830
Mange skrev:If it is explosions things go kaboom ansd is no more. Its uncontrolled.
The thing that happen after spark is a flame front that expand in volume. It is very controlled and cumbustion chamber, sparks position, flame, expansion is all very controlled.

:grin: Ok, you got me :lol:

Now to the point, where to get pop-up pistons for newer Husqvarna chainsaws? 550, 560, 572...

All I can find from market is older models 55, 346, 357, 372, 395, etc.

   TS
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 Firar 10 år som aktiv medlem på skogsforum! 
#564837 Can you find pop up pistons for 55, 346, 357, 372, 395, etc.
Were do you find them?

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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 
#564879
Mange skrev:Can you find pop up pistons for 55, 346, 357, 372, 395, etc.
Were do you find them?


Yes, for example here:
https://www.ebay.com/p/Hyway-POP-UP-pis ... 8024704913

   TS
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Re: Where to find Pop-Up pistons for Husqvarna 560 and 550 ?

 Firar 10 år som aktiv medlem på skogsforum! 
#564896 Yes, there you go.
Wonder if they have HVA261 pistons? Original they have cup in piston top on them, opposite from pop up so to say.

Fredrik Reuter
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