Chainsaw Porting Theory

[awol]

I thought the intake was in the 90's? My bad

When I get to babbling about saws and porting, all of my sentences and proper grammer go out the window, and I get a little hard to understand!

 

[drf256]

A few years ago all the pundits were saying raise the exhaust........always raise it.

My how things change.

The new Echos have crazy low exhausts. I wonder if this thinking has changed with the OEM's as well?

Have Stihl or Husky followed suit on their newer offerings?

 

[Mastermind]

Nope........they are both too high on most models.

 

[David Young]

No secrets here. I kinda doubt that I've done two 562s that have exactly identical numbers, I haven't even had a wheel on my last 5 saws! I would say though, the numbers are near:

Ex 110
In 83
Trans 101

Alan are the transfer an exhaust numbers switched, am i missing something?

David

 

[drf256]

Alan are the transfer an exhaust numbers switched, am i missing something?

David

Good point David.

I didn't even look at the transfer number.

 

[awol]

Nope, just a brain fart; after dropping the jug I raise the transfers almost as much, leaving the ex alone. That leaves the trans at about 119.

 

[Keith Gandy]

Nope, just a brain fart; after dropping the jug I raise the transfers almost as much, leaving the ex alone. That leaves the trans at about 119.

Can u port a 372xp to be faster than a 562? Torque difference between the 2?

 

[drf256]

Damn,

This thread has made me think a lot.

Think my next 036 is gonna have a lower exhaust and is gonna pull all it can oil in style.

 

[mdavlee]

That's what I was looking for.

What comp do you shoot for in that saw?

I rarely check compression unless I'm asked.

 

[paragonbuilder]

Man I wish I had the time to experiment more! You guys are really helping me learn, I need to start playing with some saws!!!
Al I picked up a ms261 you can play with if you want. It will be a while before get to that saw. I just picked it up so I could study the stratos.... Seems to big and heavy for a 50cc saw.


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[drf256]

Man I wish I had the time to experiment more! You guys are really helping me learn, I need to start playing with some saws!!!
Al I picked up a ms261 you can play with if you want. It will be a while before get to that saw. I just picked it up so I could study the stratos.... Seems to big and heavy for a 50cc saw.


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I'm learning a lot here. I have a 362 builder here. It's 40% larger in size than an 036. I don't get it.

 

[mdavlee]

Nope, just a brain fart; after dropping the jug I raise the transfers almost as much, leaving the ex alone. That leaves the trans at about 119.

That was a little backwards. The one I did I went 102/120/78 only video I uploaded was this one.

 

[Keith Gandy]

That was a little backwards. The one I did I went 102/120/78 only video I uploaded was this one.

I like the auto tune saws! I cut 9 smaller trees yesterday with my 550 and I just cant find anything I dont like about it!

 

[Terry Syd]

Damn,

This thread has made me think a lot.

Think my next 036 is gonna have a lower exhaust and is gonna pull all it can oil in style.

Here's a way to see what you need for the exhaust. Use the old piston to try different blowdown figures. Start with a stock piston height and check how the saw cuts. Then trim 2 degrees off the front to the piston next to the exhaust port, try it again. Eventually, you will go too far and start going backwards. Go back to 'the best' figure (for whatever cutting YOU do) and cut that into the jug. Then put in a new piston and ring.

 

[awol]

Can u port a 372xp to be faster than a 562? Torque difference between the 2?

A xt or OE?

There is really no replacement for displacement, so in theory the 372 should be able to outperform the 562; I just haven't spent near as much time experimenting with them. The disadvantage with a 372 is the short transfers, and lack of crank stuffers.

 

[mdavlee]

A xt or OE?

There is really no replacement for displacement, so in theory the 372 should be able to outperform the 562; I just haven't spent near as much time experimenting with them. The disadvantage with a 372 is the short transfers, and lack of crank stuffers.

They can get good power. Real simple numbers with a little compression makes a big difference.

 

[Keith Gandy]

A xt or OE?

There is really no replacement for displacement, so in theory the 372 should be able to outperform the 562; I just haven't spent near as much time experimenting with them. The disadvantage with a 372 is the short transfers, and lack of crank stuffers.

OE. I have a 2007?

 

[Keith Gandy]

The crank stuffers and revboost are very nice in the 550/562s. My 550 with a 16" picco setup just plain and simple cuts like a limbing saw should!

 

[Keith Gandy]

1. A xt or OE?

There is really no replacement for displacement, so in theory the 372 should be able to outperform the 562; I just haven't spent near as much time experimenting with them. The disadvantage with a 372 is the short transfers, and lack of crank stuffers.

Does the xt not port as good as the oe or vice versa?

 

[mdavlee]

Xtorq has a lot heavier piston in it. They don't Rev as free as the oe