Husqvarna 572 build.

[Jake Dykstra]

So my buddy Nick talked me into playing with the 572.
He really likes my ported 372 so I did one for him. Says it's faster than his 500i 390xp blah blah blah. It should be those are all stock saws. Same 28 inch bar on all saws. Anyway he said I need to do the 572 and so why not.
All be honest my first attempt sucked. No faster than his muff modded (broken in) 572. I was a bit disappointed but wasn't surprised. I mean the 572 is a not torquey feeling stock.
So my stock numbers were 100/120/76 I think. Im thinking long stroke can take a higher roof...right? Well not on this saw apparently.
My first attempt was 98/112/77. And no torque. Also that was with a 030 pop up and 050 band cut 020squish.
Second attempt new piston and left it a flat top. 103/117/77 now this ran way way better. Lots of torque and a solid 25% faster in the cut.
Third attempt. New cylinder and piston.
Cut a 5* taper in the piston and matching in squish band. .030 at the outside edge of piston.
At least. 070 out of the band. A *s-word ton off the base. Which sucked because it required a lot.of clearancing of stuff.
103/117/80 this time. I was looking for a little more snort.
Ended up with 200psi static. Well I can now tell you that 200psi is to much. It runs hot as heck! When you first start it and make a few cuts it pulls hard but after like 3 10 second cuts you can't touch the cylinder within leaving marks on your hand. Then it starts to surge when you free rev it instead of that nice sound of it hitting the rev limiter.
Anyway what I'm saying is 175psi gives nothing up to 200 and runs much cooler.
Also no timing advace

 

[Jake Dykstra]

 

[Jake Dykstra]

So my question for 572 builders is:
If cut the base say .080 how does that effect the strato ports? Good or bad?
Would raising them.back up to stock be better? Or maybe. 040?
Please explain your answer.
Thanks

 

[huskihl]

Seems like a lot to cut the base. I only remove .040” from the band and then cut the base to set squish. I don’t touch the stratos or the intake. Put a big enough hole in the muffler and they are plenty sporty

 

[redline4]

Seems like a lot to cut the base. I only remove .040” from the band and then cut the base to set squish. I don’t touch the stratos or the intake. Put a big enough hole in the muffler and they are plenty sporty

That they are.
@bradb123 has an entire herd of 572's and they are all quick. And they can do it all day too.

 

[Jake Dykstra]

Seems like a lot to cut the base. I only remove .040” from the band and then cut the base to set squish. I don’t touch the stratos or the intake. Put a big enough hole in the muffler and they are plenty sporty

No doubt they are. I just wanted to see how much more there is.
I cut the dome off the piston last night. So nothing changed other than it dropped static to 175psi. Not as hot as it was but still plenty warm.
Im just wondering if adding more strato timing would help or hurt.

 

[srcarr52]

The stratos open when the top of the piston cut out is above the bottom of the upper transfer, so you've already added a ton of strato timing by dropping the jug so much.