Porting The Husqvarna 572XP

[srcarr52]

Them FB pages seem like a free fall into chaos.

I thought it was a competition to see who could give the worst advice?

 

[Brush Ape]

Old Farts Meet Smart Phones
Old Farts Meet Bart Jones
Old Bart Farts Start Bones
Bart Jones Phones Beat Fart Moans
Bart Jones Farts Smart Bones.

 

[TreeLife]

Excited to see this!!!

 

[huskyboy]

I’m curious if Randy raised the exhaust more than he normally would because of the long stroke. Seems like they tried to get somewhat of a balance in torque and rpm with the long stroke and stuffers combination?? Or maybe the small bore long stroke is to reduce the piston weight from what the 372 xt was? The 572 feels like it makes most of its punch in the midrange (not high or low in the powerband) to me stock. Makes me wonder how a 565 runs without the stuffers... hmm.

 

[huskyboy]

What was stock compression and squish? 150 psi or so?

 

[MustangMike]

Bore/Stroke is always a trade off. Longer stroke results in a lighter piston but more travel and higher velocity. Either camp can win as long as it is done right.

Generally, longer stroke provides more torque, shorter stroke more RPMs.

 

[Mastermind]

I’m curious if Randy raised the exhaust more than he normally would

Burp.

I prefer to resist posting about those details. Past experience has taught me that if I do, I end up defending my thought processes.

Just posting this build thread went against my better judgment.

 

[huskyboy]

Burp.

I prefer to resist posting about those details. Past experience has taught me that if I do, I end up defending my thought processes.

Just posting this build thread went against my better judgment.

No problem I understand sir

 

[rocco490]

eventually i will be getting a mmws 572 thanks for the thread on it

 

[huskyboy]

I think a lot of people like there saw to run a certain way or port it a certain way. That’s cool, it’s your saw and your $. Some like peak power (I find those types are usually cutting softer woods or racing it), some like all torque (I find those types could use a filing lesson) and me? I just want a good balance, good midrange power that doesn’t fall on its face when lugged a little. I think this is where all the different opinions come from but I could be wrong lol.

 

[Mastermind]

I think a lot of people like there saw to run a certain way or port it a certain way. That’s cool, it’s your saw and your $. Some like peak power (I find those types are usually cutting softer woods or racing it), some like all torque (I find those types could use a filing lesson) and me? I just want a good balance, good midrange power that doesn’t fall on its face when lugged a little. I think this is where all the different opinions come from but I could be wrong lol.

You're exactly right.

Also, people tend to see everything in black or white, right or wrong. When it comes to building performance engines there is no one size fits all approach.

Will raising the exhaust make power at a higher rpm? Not always.

Will more blowdown help performance? Sometimes.

Does the muffler need bigger outlets? Not in every case....

If I toss out a set of numbers will they help you port your saw better? I doubt it.

There are so many variables in not only the architecture of the engines, but in a user's ability to file a chain that matches the powerband of the engine.

If anyone is interested in details. Send me a message. I'm happy to share my spec sheets with anyone.....in private.

 

[old guy]

What was stock compression and squish? 150 psi or so?

My comp is 155-156 psi after 13 tanks.

 

[TreeLife]

I typically like the powerband from the factory, but want more of it. That's what I like in a port job. I use my dogs, I can file a chain, and I can maintain a saw properly. A work saw is a work saw.

 

[rocco490]

i like a wide user friendly torque curve and good chain speed not a peaky cookie cutter powerband. Every saw i have ran from mastermind has had this quality, wide powerband and good chain speed and i dont think thats by accident. Mastermind whatever your doing it works!

 

[MustangMike]

Does the muffler need bigger outlets? Not in every case....

Can I quote this??? (Sorry, I'm just a troublemaker)

 

[MustangMike]

I typically like the powerband from the factory, but want more of it. That's what I like in a port job. I use my dogs, I can file a chain, and I can maintain a saw properly. A work saw is a work saw.

That almost fits me exactly, except I really like torque, hate getting pinched and if the saw gives me another tenth of a second to save it I'll take it!

But I also like increased cut speed, just not at the expense of a broad power band. Like you say, more of everything.

 

[huskyboy]

When I’m bore cutting with a 24” bar buried in hardwood it’s like I’m running the equivalent of a 4 foot bar (24” x2) because I’m cutting with both the top, tip and the bottom of the bar at the same time. Forgiving power is appreciated and good speed to chase backcuts as well.

 

[Brush Ape]

Is this the new where I like my powerband thread? I like a broad powerband with off idle snap. Well I like broads but like them not too idle or I might snap.

 

[junkman]

I like green powerbands ,the orange ones don't hold the rpm in the cut with .404 chain.

 

[Mastermind]

I'm not sure I've mentioned this before, but I like turtles.