Should i grind a 572.

[Evan03]

Have two 572s so im debating bumping upper transfer alittle wider and blending smoothing intake castings.
Will this make gains leaving timming alone or will i just be grinding for fun.

With the removable transfer covers i kinda think i have to do it. Its calling me.

Deleting gasket i think transfer covers and skirt extensions have to be clearanced slightly.

I also have a good running 461 but upper transfers are hard to get to. But do have a good oem cylinder for it. And its kinda a beater saw so i wont be to sad if my grinding makes negative gains.

I just cut fire wood with 28 and 32" bars most the time in 30" plus sized wood. The 461 is working well with 32" just muffler modded. Ive yet to cut with 572 in the real world.

Faster is always better.


Thanks guys

 

[Jusgunn3]

Send one to one of the pros on here and see how you like it. The 572xp will need a machine work to delete the gasket the right way plus you will get a fully ported saw vs you just grinding away at bits. Just my 2 cents.

 

[Jake Dykstra]

Good muff mod goes a long way on the 572.

 

[srcarr52]

There is not any room to widen the intake, the piston limits how wide the port can be. I leave the intake alone as machine work adds the necessary duration. They do like a little more ex duration than stock and there is room to go wider there.

 

[cuttin]

View attachment 462209

The wife might be doing some port work as well!

"but honey, I put a towel down first"

 

[Evan03]

No wife, girlfriend doesnt live with me.

So i catt bump upper transfers towards intake and then blend lowers?

 

[chipper1]

No wife, girlfriend doesnt live with me.

If she'd complain about saws on the counter, probably not the one .
I can't help with the saw, but feel free to follow me for more marriage advice...

 

[Evan03]

My wife did allow me to work on saws in the kitchen and use the diswasher as a parts washer.

 

[Evan03]

Hoing cutting this weekend. Will run it as is currently muffed. Compare to 461 that has alot of grunt in the cut.

 

[srcarr52]

No wife, girlfriend doesnt live with me.

So i catt bump upper transfers towards intake and then blend lowers?

You can work the upper transfers towards the intake a little.

But the actual intake doesn't need any work.

 

[David Young]

when starting out porting we want to feel like we are making a difference porting what we can get too. Transfer flow is an easy thing to mess up. unless there are obvious ugly boogers in the transfers I don't think there is as much to gain as people think. I don't know the timing numbers on these saws if I was in your shoes the only things I may change on the transfers is the strato timing and raising the transfers with out widening.

However,
Srcarr and others mentioned, open the holy hell out of the muffler and exhaust port. these motors are an air pump that has the flow rate dictated by pressure differentials. The more the exhaust and muffler is cleared out and the pressure decreased guess what will happen with the preceeding stage if nothing is changed in that stage? You will have more transfer flow. You will also increase volumetric efficency because you have ensured that the left over burnt charge has been evacuated.

If you want to go further there are many people (pro porters) here that will cut a cylinder for you for $50. That's cheap when you figure I'm probably 3-4k in on a lathe and tooling to cut cylinders well.
once you have the cylinder cut you can really make some changes and reach for what is left on the table.

be careful.... this slope she's a slippery one

 

[Motorka]

SO no and buy new and then port it. This old ones on picture are half done.

 

[Evan03]

SO no and buy new and then port it. This old ones on picture are half done.

? Barely run

 

[Ketchup]

I’ve not ported a 572, but I would give it a bit more exhaust height and also raise transfers to a shorter blowdown. I wouldn’t stretch them. If you want more intake, you can grind the piston skirt.

Fair warning: Porting without machine work tends to be a little disappointing.

Muffler mod is the first step and usually where the real gains begin.

Edit: Leave your 461 at a muffler mod unless you have machining capabilities and a right angle hand piece.

 

[Evan03]

461

I’ve not ported a 572, but I would give it a bit more exhaust height and also raise transfers to a shorter blowdown. I wouldn’t stretch them. If you want more intake, you can grind the piston skirt.

Fair warning: Porting without machine work tends to be a little disappointing.

Muffler mod is the first step and usually where the real gains begin.

Edit: Leave your 461 at a muffler mod unless you have machining capabilities and a right angle hand piece.

 

[legdelimber]

Evan03, Where's the outlet? Got any more views/angles of that little tucked in creation of curvatude?
The final(?) round canister portion got a stinger (perforated?) tube inside, any baffling or is it some sort of resonant chamber?...
Or if there's a link somewhere already, someone point me to it please?

I remember someone mention building a "suppressor" style baffled muffler for a saw.
I've pondered the same idea for a backpack blower, where the bit of extra weight probably wouldn't be as noticeable or in the way of usage.
-------
edit: ahhh. (I need more sleep somehow) I see more pics of it over on the "show off your muffler mods" thread. Sort of puts me in mind of some of the pipes I've seen in the "long Tail boats" racing videos.

Post in thread 'Show off your muffler mods'

Today at 12:40 AM

Messing with the 461. Had given up on the pipe thinking it made it super finicky. Turned out carb was gunked up now shes solid purring on the pipe.

• Evan03

• 

 

[Jake Dykstra]

There is not any room to widen the intake, the piston limits how wide the port can be. I leave the intake alone as machine work adds the necessary duration. They do like a little more ex duration than stock and there is room to go wider there.

Interesting you like more exhaust duration. I did a 98 roof (100 stock) and it didn't have any grunt. I would have thought with a 39mm stroke a 98 would be enough.
On the next cylinder I used all the same numbers with a 103 roof and it pulls like a train.

 

[Jake Dykstra]

Heres the 98 roof all else the same. Stock 572 with same 28 inch bar and chain was about 13-14 seconds.

 

[Jake Dykstra]

Redo with 103 roof. All else the same

 

[srcarr52]

Interesting you like more exhaust duration. I did a 98 roof (100 stock) and it didn't have any grunt. I would have thought with a 39mm stroke a 98 would be enough.
On the next cylinder I used all the same numbers with a 103 roof and it pulls like a train.

My notes say they are at 102.25° exhaust (155.5° duration) stock. I raise them to 100° (160° duration).

They seem to turn out well.