Milling with a ported saw?

[the westspartan]

Hey guys,

I have been milling pine with my 441 for over a year now and love it. I have been thinking about getting it woods ported just for the hell of it and so that I could get into some slightly bigger stuff.

Just wondering if any one here has any thoughts on milling with a ported saw verses a stock saw. Advantages/disadvantages?

 

[Can8ianTimber]

my 3120 is ported and it made a big difference. Stays cooler, more power. I used walkers saw shop in Canada and I have to say they are the first honest saw shop I have ever delt with. $200 plus shipping is all it cost.

 

[gink595]

I'm going to give my ported 7900 a try now that it is ported, just as a durability test

 

[BobL]

Hey guys,

I have been milling pine with my 441 for over a year now and love it. I have been thinking about getting it woods ported just for the hell of it and so that I could get into some slightly bigger stuff.

Just wondering if any one here has any thoughts on milling with a ported saw verses a stock saw. Advantages/disadvantages?

There are two ways of looking at what porting will do.
1) Generate more RPMs, to cut more/faster - but will the rest of the saw last as long?
2) Stay at the same RPMs and cut cooler for longer - saw lasts longer.

To cut faster, a greater chain speed is essential. This requires higher revs, or more power so the sprocket size can be increased. There may be an argument that the latter is preferable since just increasing revs means the rest of the saw will wear out quicker, although the former means greater loadings on bearings etc.

Ultimately it depends on the engineering/manufacturing margins used on the rest of the saw. I imagine the corners cut on cheaper saws means they will not be able to handle it long term. For quality saws one hopes the better quality components can take the extra loads.

If a mild/moderate port is used, some win/no lose combination of all of the above seems possible, ie use a bigger sprocket and since saw runs cooler most components should wear no quicker than a regular configured saw.

BTW : Most saws will benefit immediately from a simple muffler mod but watch your ears!

 

[the westspartan]

Thanks guys. I was told by a friend to expect a loss of torque in a ported saw, which seemed contrary to everything I had read.

 

[Brmorgan]

Thanks guys. I was told by a friend to expect a loss of torque in a ported saw, which seemed contrary to everything I had read.

Yeah your friend needs to go back to the books on that one. A proper porting job will generally allow the saw to run at a higher RPM due to increased fuel delivery, AND produce more torque over a wider RPM range, or what is commonly known as an engine's power band. While I haven't used it a LOT for milling, I have made a few cuts with my ported 181SE. And I have to say, my muffler-modded 395XP would be very hard-pressed to outcut it, even with the 14cc advantage.

In theory a ported saw should run cooler and last longer, due to the increased fuel flow pulling more heat off of the metal. However as others have noted, certain parts like bearings wear due to the pure number of revolutions they can take in their lifetime moreso than due to increased heat. If I had a choice though, I think I'd rather have to replace a bearing or two once in a while than the piston and/or cylinder, so IMO keeping the engine topend cool is more of a critical factor in the overall life expectancy of a saw. There is also the work productivity factor - if, say, the saw's life is cut short by 10% but it is 20% more productive due to the modifications, are they worth it? It might depend on your own ability to maintain and repair saws; I can do most any repair job myself if I have the parts, so the odd breakdown here and there, while frustrating, isn't the end of the world for me.

 

[tmeyers]

I need an 090 Sthil

I don't know if porting out a saw is the answer. But gigger is better! By the way does anyone know where I can get an 090? I have an Alaska saw mill and I need the extra power.

 

[motomedik]

Had a chance to compare some ported verse non or only muffler modded saws this weekend.
It occurs to me that some saws might gain torque as well as hp and or RPM when ported, especially if they were a bit lower on the toque to begin with. Some saws have a more torquey power stock, and seemed to lose torque to gain hp when ported. Also depends on the builder how they might mod for their personal preference to get the gains.
I'd be sure to let the builder know of what your intentions are with your saw before you ship it. If you plan to mod your milling saw the builder should take into consideration that it IS A MILLING SAW.

 

[woodsrunner]

I would talk with Timberwolf before you go too far with this. He is a member here. And a pretty good authority on building saw engines. I considered modding my 395 and I talked to him about this and in the end did not modify my saw. Timberwolf really knows 2 strokes and I trust his opinions.

Scott

 

[Coalsmoke]

Out here on the west coast where the timber is big, modified saws are common. My saw doctor that builds saws for a lot of guys here did my 395 XPG very nicely, port and polish, 3120 muffler, shaved head and performance piston, and some other little extras. It is a nice thing having the power of a 3120 in the package of a 395XP. Just make sure that whatever is done to it is balanced by the fuel system so you don't lean it out on the high end.

 

[WoodChuck'r]

I have been told recently that with porting one loses a lot of their low end and the power band smooths out a bit more. But (from what I was told) you can't push on the saw as much once it's been ported - it'll cut faster but any real grunt the saw has will be gone.

Strange.

 

[BobL]

I have been told recently that with porting one loses a lot of their low end and the power band smooths out a bit more.

When a port job reduces low end power that is normally accompanied by a peakier, not a smoother power band. That sort of a port is what is used for a racing saw. Woods ports are designed to lift power across the whole rpm range.

But (from what I was told) you can't push on the saw as much once it's been ported

Once again that applies to a racing ports. You can actually push harder on a woods port. I don't think any saw should be pushed, if a saw and chain are set up right it should self feed with a light pressure.

it'll cut faster but any real grunt the saw has will be gone.

If it cuts faster it must have more grunt - read Brad's post.

 

[timberwolf]

There are gains that can be had by porting a saw for milling, However the standard approach of just increasing the port durrations and bumping compression might not be the best though.

A milling saw needs torque more than it needs RPM, ported for more torque and the saw will hold more RPM in a heavy cut and cut faster. If compression is increased much over stock heat will be a problem on a CSM.

 

[Gumnuts]

$0.02 from downtown McCrae / Victoria / Au......

With milling I am locking the top end Although revs drops somewhat in
the cut ... the power band for milling is viewed somewhat differently than
a woods ported power band.
For the protection of the saw when milling a richer setting is recommended .This setting does loose revs in the bottom/mid range.....it is mid range to high rev range we are looking to.
For porting a saw for milling ,others more pronounced and knowledgable
than myself have suggested just widening the ports / muff to help with mid range torque in the cut and keeping it cooler / opening up the muff (as Bob implied, use good ear protection).That's as I understand it.
Have one 084 with this set up....can't give you stats on the diff but would say it does pull better in the cut ( mid-range)/ faster ,than before the rebuild.
Refining the set up with 8 pin and smaller gauge helps speed the cut up .
Bob and Aggiewoodbutcher posted a great thread on timed cuts using different sprockets and gauges ....worth reading - if you have'nt done so already.

 

[Gumnuts]

There are gains that can be had by porting a saw for milling, However the standard approach of just increasing the port durrations and bumping compression might not be the best though.

A milling saw needs torque more than it needs RPM, ported for more torque and the saw will hold more RPM in a heavy cut and cut faster. If compression is increased much over stock heat will be a problem on a CSM.

Thanks Timberwolf ....short and sweet.

 

[the westspartan]

I am doing it!

Thanks for all the feedback everyone! I am doing it. I made an appointment with "The Snellerizer"! I am dropping the 441 off to him over the holidays as his house is on the way to my folks place. I explained to him that this is a saw I use for milling and he assured me that I would see power gains across the board.

I plan on making and posting some before and after videos of milling and bucking.

I can't wait!!!!