Archive
AVAILABLE




TimberKing Sawmills



The Largest Inventory of Used Chainsaw Parts in the World

Toll Free 1-800-582-0470

LogRite Tools


Forest Products Industry Insurance

Norwood Industries Inc.

Sawmill & Woodlot Magazine



Wood Processing equpment. Splitters, Processors, Conveyors

Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL

Woodland Sawmills

Margeson Insurance

Peterson Swingmills

Pacforest Supply Company

 KASCO SharpTech WoodMaxx Blades

 Farmi Winch Direct

Forestry Forum Tool Box

Author Topic: Woods Porting  (Read 21448 times)

0 Members and 1 Guest are viewing this topic.

Offline Rocky_J

  • Senior Member x2
  • *****
  • Posts: 1572
  • Age: 49
  • Gender: Male
Re: Woods Porting
« Reply #20 on: February 21, 2010, 09:37:11 am »
But it is safer to run the saws with catalytic mufflers and ultra lean carb settings so there's no extra pollutants in the exhaust. All those things make the saw last longer! The government wouldn't do anything to make our saws burn up. They mandated ethanol, which protects our saw motors as well. Everything on the saw is there for the sole purpose of making the saw as powerful and as durable as possible. None of the government mandates will ever cost us a single minute of motor longevity. It's best to leave the saw 100% stock the way the government dictates it should be, because the government is so efficient and knows what is best for us.

All those mods that people talk about doing must hurt the saw, people are not as smart as the government.

Offline bandmiller2

  • Senior Member x2
  • *****
  • Posts: 6925
  • Location: Franklin Ma.
  • Gender: Male
Re: Woods Porting
« Reply #21 on: February 21, 2010, 09:41:16 am »
This subject has been flailed into submission but why wouldn't manufacturers make some of these minor improvements and call it factory porting or would the EPA get em.Frank C.
A man armed with common sense is packing a big piece

Offline Rocky_J

  • Senior Member x2
  • *****
  • Posts: 1572
  • Age: 49
  • Gender: Male
Re: Woods Porting
« Reply #22 on: February 21, 2010, 09:46:13 am »
They are not allowed. Fortunately, the EPA doesn't come into my garage and smog check my chainsaws. But new saws must meet set standards.

Offline stonebroke

  • Senior Member x2
  • *****
  • Posts: 2004
  • Age: 60
  • Location: warnerville NY
  • Gender: Male
  • I'm new!
Re: Woods Porting
« Reply #23 on: February 21, 2010, 09:50:02 am »
But it is safer to run the saws with catalytic mufflers and ultra lean carb settings so there's no extra pollutants in the exhaust. All those things make the saw last longer! The government wouldn't do anything to make our saws burn up. They mandated ethanol, which protects our saw motors as well. Everything on the saw is there for the sole purpose of making the saw as powerful and as durable as possible. None of the government mandates will ever cost us a single minute of motor longevity. It's best to leave the saw 100% stock the way the government dictates it should be, because the government is so efficient and knows what is best for us.

All those mods that people talk about doing must hurt the saw, people are not as smart as the government.



Are you sure you don't work for the Obama administration

Stonebroke

Offline Cut4fun

  • Senior Member x2
  • *****
  • Posts: 1487
  • Location: BUCKEYE STATE
    • Chainsaw Repair Site
Re: Woods Porting
« Reply #24 on: February 21, 2010, 10:36:19 am »
Well actually because of that my tree trimmer bud left his new ones stock for the 30 day warranty period Stihl puts on their pro saws . I imagine come about spring time he'll want a little enhancement done because compaired to mine his new ones are dogs . He's complained since he bought them as replacements for ones that were stolen .

That doesn't make sense, newer but slower.What's wrong with this picture  ???

Al did he get a new MS660 to replace that fine 066 he had and you brought to that one GTG?

If so look at that pencil eraser size outlet hole on the new 660. No wonder they cant get out of their way now days and are pigs new, they cant breath.

Online Al_Smith

  • Senior Member x2
  • *****
  • Posts: 7772
  • Location: Northwestern Ohio in the center of a giant corn field
  • Gender: Male
Re: Woods Porting
« Reply #25 on: February 21, 2010, 11:18:15 am »
Yes he did and as a matter of fact it is residing in my shed at the moment to prevent further theft .Sad to say that new one is a dog ,very discouraging for the one model of saw that pretty much has set the standards whereby most saws are judged by .

I kid you not I can out cut that thing with my 038 Mag ,sad indeed . :(

Actually unless it's something that requires the full use of the 36" bar on the Stihl he has been using a 281 Husky which will cut circles around that new 660 . The Husky is bone stock and 20 years old to boot .

That's what they've done to our saws ladies and gents . >:(

Offline Cut4fun

  • Senior Member x2
  • *****
  • Posts: 1487
  • Location: BUCKEYE STATE
    • Chainsaw Repair Site
Re: Woods Porting
« Reply #26 on: February 21, 2010, 11:57:16 am »
Al your going to open that muffler up for him on the stock outlet aren't you  ;D and tell him to put a DP cover on it for $50 stihl cost or make one using the stock cover like I do on the 084 cover.
Check that cage in that new 660 inner muffler. I bet it is pretty restrictive to now days.

Online Al_Smith

  • Senior Member x2
  • *****
  • Posts: 7772
  • Location: Northwestern Ohio in the center of a giant corn field
  • Gender: Male
Re: Woods Porting
« Reply #27 on: February 21, 2010, 12:21:09 pm »
Yes I'll work it over for him when he says to . Usually on an 066 model all it takes is a little muffler work as they do pretty darn good even as a stocker .I imagine that muffler work would suit him just fine as far as any enhancement goes .

You know for most people just a little muffler tweak is all they ever want  because it does wake up the saw quite a bit .Besides that it is in essence free  if you do it yourself .

Like say a 200T .It's pretty much standard proceedure to jettison the screens on them by just about any pro user I've ever seen .The only people who don't are on the forums saying you shouldn't . In the real world it's much different . :D

Offline bandmiller2

  • Senior Member x2
  • *****
  • Posts: 6925
  • Location: Franklin Ma.
  • Gender: Male
Re: Woods Porting
« Reply #28 on: February 21, 2010, 02:48:16 pm »
Its sad what their doing to the new saws to save squat.Its safe to say I'll never be buying anouther new saw,got about 10 good saws if I live long enough to wear them out I'll be filling my depends with sawdust.Frank C.
A man armed with common sense is packing a big piece

Offline Screaming Detroit

  • member
  • *
  • Posts: 9
Re: Woods Porting
« Reply #29 on: February 21, 2010, 05:50:30 pm »
Seems that there are some good builders in the midwest, and a few out here in the west west. I have run some here from Dean and Jasha, and one DN saw. They all ran really good, but this was at some GTG events where people bring their good saws to.

As for bad porting, that can and does happen. Even from some of these builders. I have seen some not so well ported saws come on the market with some rather shady statments about performance. I also have to question when some guy wants to sell a woods ported 361, and will consider a trade for a stock 361. Makes you wonder why he wants a stock 361? Oops...

You need to treat the transfer ports with respect, and you can screw up the mechnical timing pretty bad if you mess up the ports. I have seen guys pull the jug gasket out of a saw (or thin it and put in a Bud can gasket) just trying to raise the compression of a low compression saw. They would have been far better served to replace the rings. I have also seen exhaust ports made too wide on Stihls that nearly clip the rings. I have also seen saws with gobs of low end torque, but they cannot cut for crap when WOT. Porting affects the torque and power curves, where they peak, and the response of the saw.

As for muffler mods in woods porting, that is typically done to help the ported saw move the gasses along better. Porting can be done in stages of complexity and stopped at any point, and some stages can be skipped:
1) muffler opened up and/or gutted and/or the CAT removed and carb re-tuned richer
2) cylinder ports opened up and polished
3) cylinder base turned down and the outside of the piston crown turned down
4) Transfer ports opened up and/or polished, piston lightened/polished
5) Carb rejetted or swapped out with a bigger carb
A non-limited coil can be added at any time.

Note also that some saws do not lend themselves to being woods ported. For example, the Stihl 1123 and 1127 line of saws. They have clamshell engines, and are nearly impossible to squish. So you can mod the muffler and widen and polish the ports, and retune the carb, and you are done. On my 310, I just opened up the muffler and re-tuned the carb. Easilly a 10% gain. Took all of an hour. On my 044 I added an 046 factory dual port muffler cover and retuned the carb. Similar results, but it only took 15 minutes. On my 066 I added a custom dual port cover, retuned the carb, and replaced the rev limiter coil. I got between a 15-20% gain from that one. On all of my 026s (five or six of them) I have done mild muffler mods to full port jobs. I am still messing with them trying to find the best setup.
In stage three you said turn down the out side of the piston, how much and is this so it inhales and exhales better?

Online Al_Smith

  • Senior Member x2
  • *****
  • Posts: 7772
  • Location: Northwestern Ohio in the center of a giant corn field
  • Gender: Male
Re: Woods Porting
« Reply #30 on: February 21, 2010, 08:13:57 pm »

       In stage three you said turn down the out side of the piston, how much and is this so it inhales and exhales better?
Those so called "Stages " are just terminoligy a few saw engine builders dreamed up.

The reason for a pop up piston is several fold .If you cut a pop up it maintains the compression better ,causes the flame front to spread better and in essense raises the exhaust port without exposing a lot of piston to the exhaust which has a tendency to burn the piston .

Not everyone does it and still have really good running saws .It's just one method to enhance performance .

How much of a pop up depends on who is doing it I suppose .I have an 038 mag with a 30 thou pop up and a 200T with 12-15 thou . I've seen as high as 40 or so thou on saws done by others .There may be higher than that but none I've ever personally seen .

Offline windthrown

  • Full Member x2
  • ***
  • Posts: 244
  • Age: 56
  • Location: Great Pacific Northwest
  • Gender: Male
  • Never give a inch!!!
Re: Woods Porting
« Reply #31 on: February 22, 2010, 01:32:36 pm »
Windthrown,you must fall in the "lot of man" catigory,I've never cut west coast.Only know northeast trees.How does porting affect the longevity of a saw in the work envourment??If you used two identicle saw one wood ported outher not which would live longer?? thanks Frank C.

Well, I do not fall trees with my willie. ;)

"Woods" porting as it is called is targeted to modifying a daily runner, so the porting is less aggressive/lighter than for a race saw. If they are done right, a woods port can enhance the life if a chainsaw. They will run cooler and breathe better and have more power. If they are done wrong, they can create a less lively saw. For these reasons I generally leave the transfers alone and leave the mechanical timing set to stock or near stock values. I do light port grinding for better engine breathing, shave the jug down just a smidge, open up the muffler to original stock design or a bit more, and tune the carb richer. Also note that in most cases a modified saw will not gain any value on the market. As stated, porting will void the warantee, and in many cases builders create some odd-ball saws that just do not have the power that would be desired from a ported saw. However, when they are done right, the ported saws have better power, better response, they run cooler, and in many cases they will outlast their stock cousins becasue they do not run as lean. Lean saws run hot, and running hot can lead to engine scoring, typically on the cylinder wall below the exhaust port where the most heat builds up. 

As for why companies do not port their own saws, it is the result of US EPA laws. In many cases they do make more open saws, but they are not for sale in the US. For example, the European Stihl 361 and 290/310/390 saws have better (more open) mufflers and richer carb settings. In many cases they originally made and sold more opened up saws in the US and they have become choked up over the years due to Federal EPA (and California state) regulations. The Stihl 026/260 is a good example of this. The early model 026 mufflers had more or larger ports in them, and the carbs were fully tunable. Now they have choked up mufflers and smaller ports, internal baffles, and they have limiter caps on the carbs to keep them from being richened up. By law no dealer can modify a chainsaw or face stiff penalties from the EPA. The EPA sent out flyers and notices to all chainsaw and small engine dealers late last year warning about doing any modifications. Owners are not restricted or limited by these laws though. ;)

Stihls: 440R, 361, 360, 310, 260, 211, 020T. Husky: 372xt.
I ship Stihl saws down under: message me for details.

Offline windthrown

  • Full Member x2
  • ***
  • Posts: 244
  • Age: 56
  • Location: Great Pacific Northwest
  • Gender: Male
  • Never give a inch!!!
Re: Woods Porting
« Reply #32 on: February 22, 2010, 02:21:40 pm »
Quote from: Screaming Detroit
In stage three you said turn down the out side of the piston, how much and is this so it inhales and exhales better?

The main reason to turn down the piston crown is not for better gas flow from an intake to exhaust gas flow perspective (in some cases it actually screws it up *see below). Nor would you turn down the piston alone. That would lower the compression and make the squish larger (both bad from a performance standpoint). The main reason that pistons are turned down is for increasing engine compression when done in combination with turning down the cylinder. Higher compression will usually result in more power. To increase compression, most builders turn down the base of the jug. You can also remove the base gasket, or use a thinner gasket to get the same effect. Turning down the jug a lot or using a no gasket may casue a problem in that the outer crown of the piston will hit the top of the cylinder at TDC in the outer squish area. To prevent this from happening, the outer rim of the piston crown is turned down which domes up the piston crown center and prevents the piston from coming into contact with the cylinder head at TDC. The second reason that pistons are turned is to get a thinner squish band area. This has to do with the combustion chamber and piston crown shape. The gasses are pushed out of the squish area from the outside of the cylinder/piston just before TDC toward the dome area of the cylinder 'head'. This causes good movement and mixing of the fuel, prevents dead space and pockets of exhaust gas from forming, prevents uneven burning of the fuel, and helps to prevent pre-ignition. These are all good things.

There are several 'rules of thumb' regarding the limits to take the squish. The squish is measured at the outer edge of the piston at TDC. Typically you measure the squish by poking a thick solid solder wire bent at the tip into the spark plug port and push it in to touch the side of the cylinder wall with the piston below TDC. Then pull the piston up to TDC and back down, and then remove the solder wire and measure the thickness of the squshed end. A stock saw might have a squish of 0.035-0.04". Typically a woods ported saw would have a squish somewhere around 0.02", and a race saw might have as little as 0.01" squish. The stock and building recipies vary a lot in terms of squish. The piston turning limit is that you do not want to turn the piston down into the top ring slot, and you need to leave a gap (minimum 0.1") between the crown and the top ring slot.  

* Note that turning the piston and cylinder base down both change port/mechanical timing of the intake, exhaust and transfer ports. They also counter each other; lowering the jug directly lowers the ports, and lowering the piston crown in effect raises the ports back up. Typically squish is decreased on a ported saw, so the net effect is that the ports are lowered. Note also that you can increase the squish by turning down the cylinder without turning down the piston. But in this case, you are lowering the ports.
Stihls: 440R, 361, 360, 310, 260, 211, 020T. Husky: 372xt.
I ship Stihl saws down under: message me for details.

Offline John Mc

  • Senior Member x2
  • *****
  • Posts: 2632
  • Age: 52
  • Location: Monkton, Vermont
  • Gender: Male
Re: Woods Porting
« Reply #33 on: February 22, 2010, 06:10:43 pm »
Windthrown,you must fall in the "lot of man" catigory,I've never cut west coast.Only know northeast trees.

Remember, Windthrown mentioned he is bogging it in 3 ft DBH trees. probably not too many of them in your neck of the woods, are there, Bandmiller.
Small time fire-wooder in a neighborhood cooperative.

If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Offline bandmiller2

  • Senior Member x2
  • *****
  • Posts: 6925
  • Location: Franklin Ma.
  • Gender: Male
Re: Woods Porting
« Reply #34 on: February 22, 2010, 09:04:26 pm »
John,there are more than you think,just yesterday I was walking in my neighbors woodlot many ewp in that 36" catigory wether their solid to the core I don't know.Most of the logs I get are from a tree service and come off old estates and yards some are real lunkers but I don't like working with them,16" to 18" is what i like.Frank C.
A man armed with common sense is packing a big piece

Offline JohnG28

  • Senior Member x2
  • *****
  • Posts: 1317
  • Age: 31
  • Location: Central New York
  • Gender: Male
Re: Woods Porting
« Reply #35 on: February 23, 2010, 11:54:33 am »
Well I got a chance yesterday to see a fully done saw, stihl 046, ported, squished, mm, in action, and I can definately understand now why someone would mod their saw, that thing ate the tree like nothing, when my warranty is up on my saw I may look into some light mods, and thanks to forum member mark for the demo and look at your operation, appreciate all the info...thanks to all of you as well for all the details and great explinations of everything
Stihl MS361, 460 & 200T, Jonsered 490, Jonsereds 90, Husky 350 & 142, Homelite XL and Super XL

Offline Mark K

  • Senior Member
  • ****
  • Posts: 613
  • Age: 36
  • Location: verona ny
  • Gender: Male
Re: Woods Porting
« Reply #36 on: February 23, 2010, 10:42:06 pm »
Glad to have you stop by. Let me know if you want that 361 done. I'm thinking about having my newest 385 done. I'm trying to contact the builder that did the 046. Feel free to stop in anytime.
Husky 372's-385's,576, 2100
Treefarmer C7D
Franklin 405
Belsaw m-14 sawmill

Offline Rocky_J

  • Senior Member x2
  • *****
  • Posts: 1572
  • Age: 49
  • Gender: Male
Re: Woods Porting
« Reply #37 on: February 24, 2010, 07:55:56 pm »
Here's a video from today of my seven year old ported Husky 346 (46cc). I've never been inside the motor since it was ported and it gets run a lot.


Offline JohnG28

  • Senior Member x2
  • *****
  • Posts: 1317
  • Age: 31
  • Location: Central New York
  • Gender: Male
Re: Woods Porting
« Reply #38 on: February 26, 2010, 12:37:50 pm »
Nice Rocky, looks like youve got quite a ripper there
Stihl MS361, 460 & 200T, Jonsered 490, Jonsereds 90, Husky 350 & 142, Homelite XL and Super XL

Offline Rocky_J

  • Senior Member x2
  • *****
  • Posts: 1572
  • Age: 49
  • Gender: Male
Re: Woods Porting
« Reply #39 on: February 26, 2010, 04:53:40 pm »
I've had four other 346's built for me by three builders and none have come close to matching this one. I have another one on order with yet another builder right now, which was why I made the video. The saw wasn't prepped at all for that clip and hadn't been serviced in over a week. And probably 30 minutes cutting time since the last chain sharpening. I don't race saws, I just work them.