Husqvarna 50/51/55 - Meteor P&C Performance Build

[redfin]

Nice details here Josh

 

[watsonr]

Although visual presentation may catch your eye or the "perfect port shape" of the intake or exhaust... it may not make any difference when running the saw.

 

[wcorey]

Good stuff here...
Seems like just cutting the base for minimal squish would be an all-in-one improvement, moves both the int and ex numbers in a good direction.

I'm wondering if the vertical transfer divider is at least partly there to support the bridge, since
the transfer goes straight up and the bridge needs to be thin to avoid being a choke point.
It does appear that they just mimic-ed the op cylinder and then added the bridge without much thought to flow...
Of course the divider is also an obstruction but it is at least going in the right direction and may have some sort of benefit in directing flow.

 

[PogoInTheWoods]

Seems like just cutting the base for minimal squish would be an all-in-one improvement, moves both the int and ex numbers in a good direction.

My thoughts as well. That said, compression on mine w/o base gasket (and squish not even measurable with .032 solder) was still 162psi. I was surprised.

 

[watsonr]

Most ordinary people just want a saw to cut wood with no regard for squish, port shape or performance of +/- a second or two... we here are an elite group of chainsaw freaks! People in second and third worlds have a great day just to cut wood, find gasoline and eat dinner.

 

[Duke Thieroff]

Most ordinary people just want a saw to cut wood with no regard for squish, port shape or performance of +/- a second or two... we here are an elite group of chainsaw freaks! People in second and third worlds have a great day just to cut wood, find gasoline and eat dinner.

Agreed!

And these kits will make sure your saw cuts wood.

There has been some intrigue based around these kits though recently and it is my belief that Josh wants to shed some light onto them.

 

[watsonr]

And I'm all for it.....
My comment was to the I'd like to see a nicer finish and better port shape. I could care less about those aspects of the kit, I want to know if it runs well and functions as designed. I learned my personal opinion doesn't count for squat.

 

[Peter White]

Dis it just me, or do the OEM photos not show up? Hate it when that happens...

 

[Duke Thieroff]

And I'm all for it.....
My comment was to the I'd like to see a nicer finish and better port shape. I could care less about those aspects of the kit, I want to know if it runs well and functions as designed. I learned my personal opinion doesn't count for squat.

I'm right there with ya Randy.

My day job revolves around running a meat department for a regional grocer and I do $6 million give or take in annual sales.

I'm responsible for roughly 220 linear feet of self service case and 24 ft of presentation case.

There are some things that are synonymous with that business that is the same here...

90 percent of my business takes place out of the self service case, the other 10 percent is in the presentation case.

With that being said, maybe 90 percent of folks just want a piece of meat for dinner and the other folks want a piece of meat presented and displayed in the best possible manner.

Same with cylinders...90 percent want a good runner. 10 percent want a good runner that's pretty!

 

[Duke Thieroff]

Ain't no cylinder, even OEM, a perfect 10 under scrutiny.

But these are as close as it gets, for sure, at the price point

 

[PogoInTheWoods]

Still wonder about the excessive squish...

Also wonder where the point of diminishing returns occurs when shaving the base for tighter squish vs. the effect on the port timing when doing so...., at least in the case of this particular kit. I'm hardly there yet on my understanding of two-stroke theory and hope the topic sorta evolves to cover that aspect here in this thread.

 

[RedneckChainsawRepair]

Same with cylinders...90 percent want a good runner. 10 percent want a good runner that's pretty!

Me I just want good replaceable bolt ons for others to use as cheaply as possible. Thats all the end users around me care about.

Thanks to Saw Salvage and CCC for helping get the end products with the best prices in our hands to do chainsaw repair etc for other folks too.

 

[PogoInTheWoods]

There has been some recent press surrounding the 46mm Meteor Piston and Cylinder kit for the Husqvarna 50/51/55. I had a burned down Closed Port 55 donated to me by a good friend. As such, I decided it would be a good time to build this saw using the 46mm Meteor kit and provide an honest review of the product quality and out of the box performance.

Last time I checked, this was the subject and intended focus of the thread. Be kinda nice to keep it that way and let the man proceed accordingly.

Just sayin'...

 

[Duke Thieroff]

Still wonder about the excessive squish...

Also wonder where the point of diminishing returns occurs when shaving the base for tighter squish vs. the effect on the port timing when doing so...., at least in the case of this particular kit. I'm hardly there yet on my understanding of two-stroke theory and hope the topic sorta evolves to cover that aspect here in this thread.

My contact at Meteor stated that cylinders are cast from OEM castings, with minimal changes(to save on production costs), if any at all.

With that being said...I have made the following speculations (just somewhat educated guesses)

Let us consider that Meteor is located in Italy. What do we have here in the US that Meteor does not have in Italy?
The EPA!

Now we all know that some cylinders are designed specifically for the US market as a result of meeting certain EPA regulations, which I believe had some effect on this series of saw going from closed to open port design (correct me if I'm wrong.) In my educated guessing I have strongly considered that this cylinder is of OEM design, but from an origin us 'Muricans wouldn't be familiar at looking at as a result of different cylinders from different markets. I have a hard time believing that Meteor would import an OEM Husqvarna top end from the US bound for the US market whenever they could easily source one locally.


What thinks you on this matter?


Sometimes I wonder if compression is as valuable as we make it seem Poge.

The jury is still out on that in my opinion....

The reason I say that is I've had some mean Poulan saws which had bare aluminum bores and chromed pistons (3400s and some others) which run absolutely fantastic on 130lb of compression. 140 is generally considered stout for that series of saw.


Maybe we can get someone in here with saw building experience to chime in and talk about compression and how much difference 10-20lb of compression makes in the real world.

You know one without all of our fancy measuring devices just so we can "know."

Say you're at a GTG and a saw runs unbelievably well, is the compression a question or has the saw already spoke for itself regardless of what kind of measurement we want to put on it?

Obviously compression is an important thing, it's one of the big four that an engine needs to run, but if it's healthy do we need to get all messed up over a few hundredths of an inch?

Is compression really the all important thing in what makes a healthy engine, if good port timing and quality materials we're removed from the equation? Could the engine run well on 200lb of compression alone or is it just a piece of the pie?

I guess the question is, could I tell a saw, on the same chassis had 10 more lb compression, without the help of a gauge?

 

[Duke Thieroff]

Last time I checked, this was the subject and intended focus of the thread. Be kinda nice to keep it that way and let the man proceed accordingly.

Just sayin'...

Tell Josh to put the beer can down and get to typing!

 

[fearofpavement]

I've got a couple of these saws in line for refurb so this is an interesting thread for me.

 

[Uzi]

I'll be following this one really closely. I rebuilt a CP 55 with a no-name 51 piston that I cut windows into last year because I couldn't find anything that fit the closed port cylinder. Some people myself included were skeptical about it cracking and coming apart in a blaze of glory at 14k rpm. It hasn't and I've used it a ton but its great to know there something out there hoping its runs as good as the factory CP cylinder.

 

[watsonr]

Sometimes I wonder if compression is as valuable as we make it seem Poge.

The jury is still out on that in my opinion....

The reason I say that is I've had some mean Poulan saws which had bare aluminum bores and chromed pistons (3400s and some others) which run absolutely fantastic on 130lb of compression. 140 is generally considered stout for that series of saw.


Maybe we can get someone in here with saw building experience to chime in and talk about compression and how much difference 10-20lb of compression makes in the real world.

You know one without all of our fancy measuring devices just so we can "know."

Say you're at a GTG and a saw runs unbelievably well, is the compression a question or has the saw already spoke for itself regardless of what kind of measurement we want to put on it?

Obviously compression is an important thing, it's one of the big four that an engine needs to run, but if it's healthy do we need to get all messed up over a few hundredths of an inch?

Is compression really the all important thing in what makes a healthy engine, if good port timing and quality materials we're removed from the equation? Could the engine run well on 200lb of compression alone or is it just a piece of the pie?

I guess the question is, could I tell a saw, on the same chassis had 10 more lb compression, without the help of a gauge?

I did a threat a few years ago (maybe not that long but something like that) and said the same thing... its a number relied on to determine running condition all to much here. So many threads about "my compression is 140" do I need a rebuild". I've got saws that run in the 85-115 psi range and they run pretty well. I don't think the average guy could tell the difference between 140 and 15o by the "seat'o the pants meter". Built a Dolmar 6400 with a BBkit, had 120psi, threw chips 20', ran like the dickens! Started easier than the 160psi 64cc top end and out cut it, could tell with my eyes closed. Put the gauge to it, 120... still ran great and still does. The new owner is a personnel friend, you couldn't get that saw from him at twice what he paid for it, he cuts production firewood, going on two years for that saw now!

I think it's part of the equation, not the solution. It adds to the bottom line... torque. Saws like Stihl and Husky run much higher RPM and I believe they need more compression to run. A lower compression in a shorter duration of time has more effects on a running high RPM saw than lower compression over a longer time period if that makes sense and I believe a good running saw has more to do with spark timing than we realize. Saws that have high compression and the spark timing is off, run like crap!

130psi on a Homelite XL-Super runs at 6000rpm and runs pretty well. A Stihl at 13,000 rpm with 130psi won't run well, if at all.... why? We took some compression away... I do believe there is a minimum number needed, what that number is I couldn't tell you. I also believe that compression number needs to be more when RPM is increased.

After all is said and done, our favorite saw builders are fine tuning the compression and port timing. What happens when they leave compression alone, saw still runs on increased volume... means less torque, I can't push down as hard.... The correct fuel/air mixture (whatever the volume), compressed at the right number and sparked exactly at the right time = a running saw.

I may be screwed up....just my thought on lower compression.

 

[RedneckChainsawRepair]

120psi to 140psi easily felt IMO in my 372's when I was running them. When down to 120 they just didnt have the pop pop pop and easily pulled over at start. Still ran and cut fine at 120psi. But knew it could be so much better.

The 140psi was after only 30secs of run time. Wonder what it is up to today.

120 on left, new right

 

[drf255]

Subscribed