hard time finding the right piston husky55

[PogoInTheWoods]

Last time I checked, only one guy in this thread has actually demonstrated that he knows what he's talking about.

It's been a very educational and amicable discussion with a good vibe for a change around here...one of the better threads I've read lately.

Be nice to keep it that way. Just sayin'....

 

[samhop]

a found a piston for my154se actually a 254 piston it has a bigger pin and looks a little higher so i think it would need a hat to go with the bushings but wood work.

 

[samhop]

I did the fuel line and filter than had to clean the carb it fired up seems strong, but i did not have time to get it in the wood.

anyone know how to post a video?

 

[PogoInTheWoods]

Interesting aftermarket idea, huh? Meteor's 46mm 55 top end...

(OEM is completely open port and doesn't have the bridge, but does use a non-windowed piston.)

So what say the masses..., open port or closed port?​

(pics courtesy of Definitive Dave from another discussion on the closed port/open port subject)






​

 

[wcorey]

OEM is completely open port and doesn't have the bridge, but does use a non-windowed piston.)

So what say the masses..., open port or closed port?

Still continuing along the learning curve I see, lol. I guess that's a good thing...
Maybe there's vindication here in the alternate venue.

So Quad port or dual...? 'Open quad'...?

 

[PogoInTheWoods]

LOL Yeah, couldn't resist passing the pics along considering the overall essence of this thread is what really got me thinking about the issue (relative to the Husky 50 series anyway) in the first place. One of the better and more civilized AS threads involving a couple of the more knowledgeable folks around here...at least back then. Haha!

Plus, Joey's solution IS the Meteor approach and nobody thought there was (is?) a "closed port" AM kit for the 50 series, which there arguably seems to be...sorta, at least these days. And from general opinion and video presented here, the design certainly seems superior to either of the OEM or other AM alternatives.

I'm sticking with "hybrid" as my "official" opinion since most folks would suggest if the charge is passing around a piston instead of through it that the ports are 'open' (as in all the way to the crankcase) regardless of a bridge, while a closed port design passes the charge through the windows in the piston as the cylinder ports are 'closed off' from the crankcase.

Actually, I think I'll go way out on a limb here with "quad hybrid". That oughta just about cover it, don't ya think? Ha!

 

[PogoInTheWoods]

BTW, I just got one of these kits in the mail from DDave today and it looks real nice. I'm anxious to get it on one of my 55 projects and see how it performs. From everything I've read in this thread regarding Joey's approach, I have a good feeling about how the 46mm Meteor kit is gonna fly.

 

[71dart]

That cylinder looks nice.It looks a lot like what Joey did only 'quad'ish. Let us know how you like it.

 

[Cantdog]

L

Interesting aftermarket idea, huh? Meteor's 46mm 55 top end...

(OEM is completely open port and doesn't have the bridge, but does use a non-windowed piston.)

So what say the masses..., open port or closed port?​

(pics courtesy of Definitive Dave from another discussion on the closed port/open port subject)

View attachment 395408

View attachment 395411


​

Sigh.......LOL!!!

 

[stihlbro]

BTW, I just got one of these kits in the mail from DDave today and it looks real nice. I'm anxious to get it on one of my 55 projects and see how it performs. From everything I've read in this thread regarding Joey's approach, I have a good feeling about how the 46mm Meteor kit is gonna fly.

By all means keep us posted on how it performs.

Joey

 

[nmurph]

Lots of CP cylinders don't use windowed pistons.

There are lots of OEM cylinders designed in a similar fashion as this Meteor set.

I'm fine with it being called a CP.

I may have to get one of these to compare it to an OEM CP.

 

[stihlbro]

The Oem closed port cylinder transfers are shaped as a loop, the open ports run straight up and take a direct 90 to the piston. I can't tell from the picture but does the meteor kit transfers run straight up and 90 like the factory open port???

 

[PogoInTheWoods]

I'll double-check a little later and report back.

And yeah, Robin, I know, I know!!! LOL

Was just hoping to get a little more discussion going over here in my never ending quest for controvers..., errrr, knowledge.

 

[troylee]

Brad, would having the 55 you built me, help in a direct comparison of this new theory on the 55cp. I could pack it up and send it your way, if you wanted.

 

[stihlbro]

With out having a actual meteor cylinder in my hand, it appears to me the transfers run straight up the side of the cylinder just like a factory open port does. The factory closed ports loop, you can tell by the clearance added on the flywheel side of the cylinder. So it being a bottom fed design, the divider added to the middle, the bridge to me is nothing more than for ring support and the fact it's 46 mm might be a good replacement for the the love of these saws to keep going. To say how it performs is going to be a debatable factor and until some one does the comparison it is yet to be determined.

Your thoughts?

 

[PogoInTheWoods]

I have all three lined up on the bench but won't be able to get to em for a while yet. Will post pics, but I believe you're correct in the closed port having more of a sweep compared to the very straight open port which is how I believe the Meteor is as well.

My thoughts? They usually get me in trouble, so I'll just sit back and observe for now! LOL

 

[wcorey]

The factory closed ports loop, you can tell by the clearance added on the flywheel side of the cylinder.

What about the Husqvarna 268 (op) or 42, they both have the 'loop' design you're referring to but no bridge. The cp and op transfer bulges look almost the same from the outside and are difficult to tell apart from this feature alone. Both of the open port ones have a vertical divider part way up, similar to quad port without a bridge.
Both are widely considered to be open port and with less performance than their closed port counterparts, 268xp, 242xp.
I have both versions of both cylinders to compare and the port sizes, shapes and timing are very close on each pair.
So where is the performance difference coming from?

 

[stihlbro]

Not sure, the looping of the transfer ducts??

 

[pioneerguy600]

Three things to consider, port timing, squish and cc`s/shape of the combustion chamber.

 

[Cantdog]

What about the Husqvarna 268 (op) or 42, they both have the 'loop' design you're referring to but no bridge. The cp and op transfer bulges look almost the same from the outside and are difficult to tell apart from this feature alone. Both of the open port ones have a vertical divider part way up, similar to quad port without a bridge.
Both are widely considered to be open port and with less performance than their closed port counterparts, 268xp, 242xp.
I have both versions of both cylinders to compare and the port sizes, shapes and timing are very close on each pair.
So where is the performance difference coming from?

The major power difference between open port and closed port cyls has nothing what so ever to do with where the transfers are fed from or whether or not the pistons have windows. The most important difference is the fact that in a what is commonly called a closed port cyl the upper transfer is static in size and flows, more or less the same amount of fuel and velocity, directed accurately into the combustion chamber though out the entire stroke once the piston passes (opens) it on the way down. The open port cly transfers open and get larger and larger as the piston get lower....thus slowing and not directing the charge as accurately into the combustion chamber. There are a number of other things that come into play when making power but the difference between CP and OP being the greatest. The early CP cyl all fed directly from the crankcase and had non windowed pistons....in the true Jonsereds some of these would include the 52, 621, 70, 80, 90, 111S and others. In the later CP cyls, the XP Husky 266, 268, 272 etc. etc. etc. and Jonsered 630, 670, etc. etc. had the loop charged transfers that did not extend all the way to the crankcase and had windowed pistons. These are simply two different approaches to the closed port cyl.

As you can see in Bill's pics of the 268 Gilardoni open port cyl the lower transfers do not feed directly from the crankcase but terminate 1/4" or so from the bottom of the cyl. This does not make this a CP cyl.......