Woods Porting

[JohnG28]

Ok, Im still a little new to some stuff regarding saws, and I have read about people woods porting saws. What exactly is woods porting?

[windthrown]

Woods porting may be any of a number of things. They typically include: opening up the muffler (by grinding, drilling, or adding factory port options), opening up the intake and exhaust ports (by grinding and polishing), lowering the jug by milling or using thin/no gasket to raise the compression (called squish), turning down the piston around the top edge to allow for more squish, and tuning, rejetting or replacing the carb to allow for a richer gas flow. More radical porting may also include modifying the transfer ports and/or changing the mechnical timing of any or all of the ports (by grinding and polishing). It may also include removing material from the piston to make it lighter and polishing the piston ports under the skirts. It may also include changing the coil out to a non-limited type if it had a coil RPM limiter. Typically woods ported saws have a higher WOT RPM (at the max of factory specs, or higher). Generally the woods port is a less radical version than race porting, as the woods port is done on a saw that is intended to be a work saw run all day in the woods.

[JohnG28]

Thanks for the info, i figured that it had something to do with mods to muffler, but had heard those mods referred to as just muffler mods, so I didnt know if there was something different that I was missing...sounds about like the equivalent to tuning a sports car to tweak out more performance, and many saws would be the woods equivalent of a sports car, thanks again for clearing that up for me

[Cut4fun]

To give you a idea, a comparison between a stock Jonsered 490 and a ported Partner 5000. Same type piston and cylinder is used on both saws. Now the 490 only has 325 stihl RS chain and the 5000 pulls 3/8 stihl RS.

Now be warned not all builders get the same gains out of there ported saws. BEWARE and check and choose your builders closely, you may not be getting what your paying for. Just because they are hyped up by others dont make them good builders. 

stock 490

http://www.youtube.com/watch?v=3HwYSciPjIA

ported 5000

http://www.youtube.com/watch?v=VOFqt6cO0zc

[thumper]

other than my hyped up self  a cheap mic, all sorts of grinders and a basic idea of porting (maybe death of saw )  who actually does reputable cylinder work for work saws, at a good price? nobody in my area does this type of thing. they all think im wasting my time when i modify anything.

[Cut4fun]

nobody in my area does this type of thing. they all think im wasting my time when i modify anything.

I can't figure out what area your talking about without telling us. 

[thumper]

the great old northern maine..

[windthrown]

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.

[Al_Smith]

It's a lot of fun to twiddle and fiddle to soup up a saw . I've had pretty good luck at it myself but it's not for everybody .

You can't just carve away on them though without a plan of action or chances are the end results will be less than desirable . It does little good to have an engine that runs 15,000 RPMs but doesn't have power to push a pizz ants motor scooter .

[Rocky_J]

I've bought porting work from several builders over the years and have learned that nothing is guaranteed except inconsistency. I've had a couple exceptional saws, several duds and most have had modest gains but not as much as I expected. I guess the couple of exceptional saws have ruined me. Most of the builders I've dealt with (after following them on these forums) have horrible turnaround times. 6-8 weeks is average and sometimes your saw can disappear for several months, then you are the bad guy when you complain. I've weeded through a lot of saws (and builders) and finally have every saw in my arsenal ported and performing to my satisfaction. It hasn't been cheap or quick.

I have high hopes for the latest builder I've used. He did a very nice job on my 395xp last year and was thorough and prompt with it. I like the fact that he's a perfectionist. Unfortunately he's in Ontario, Canada so the shipping back and forth isn't cheap, and using UPS isn't an option due to Customs duties and taxes. But considering what my saws earn me over their lifetime, a few dollars shipping is nothing.

[JohnG28]

Thanks again for all the clarification guys, its appreciated, and thanks for the videos Cut4fun, they definately show the differences well

[bandmiller2]

You guys must be alot of man.I keep trying to outwork my 046 stihl and loose every time,it wants more wood I want a nap.I think the money spent for porting would be better spent on sharp files,only my opinion,old and grumpy.Frank C.

[bandmiller2]

Rethinking the porting thing I can see where a bucket jockey could use a ported saw where weight ,compact size and power are important.If you can cut a branch quick enough before it realizes its been cut it will fall straight down not swing on its hinge.Frank c.

[Al_Smith]

It's just neat to have a fast saw . In my case it's a challange to make it fast .

Some people like souped up cars, computers ,fast boats .For me getting the saws built is a much fun as operating them but then again I'm just a tad eccentric 

[Cut4fun]

A timber faller broke down how much more production he took in on a day when using his woods ported saws. Like he stated time is money.

[windthrown]

You guys must be alot of man.I keep trying to outwork my 046 stihl and loose every time,it wants more wood I want a nap.I think the money spent for porting would be better spent on sharp files,only my opinion,old and grumpy.Frank C.

Hmmmmmm. I could bog down my stock 460 falling 3 foot DBH trees. They are fairly easy to over-lever and bog with the dogs set in a buck or back cut. Even with a razor sharp chain. I added a DP muffler cover to my 044 with a light port mod and it easilly runs with the stock 460 now. A tad less weight and way less vibration than a 460. Easier to control, less tiring. I sold my 460. I don't need it, and the vibration killed me when I used it.

The 460 DP muffler cover for my 044 was $35 at Stihl. The labor to port my 044 was 'free'. Well, the tach cost me $85. But anyone would be well served in getting a good tachometer if they make a living off of their chainsaws. When they were stihl available, a new 440 with a DP cover was a lot cheaper than a new 460 as well. Money to buy lots of files with. 

440 vibration: 4.2/4.5 m/s*s ( measured left/right )
460 vibration: 4.2/6.0 m/s*s ( measured left/right )

440 weight: 13.9 lb. (full wrap like I have 14.8 lb.)
460 weight: 14.6 lb. (full wrap 15.2 lb)

[bandmiller2]

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.

[Al_Smith]

Most people have pretty good luck as far as longevity of use from most "enhanced " saws . I suppose there are exceptions to that rule though .

Stop and think about it though .If all you did was reduce the back pressure on the muffler  and retuned the carb it first will run better and produce more power .In addition it will run cooler . It would make sense that alone would add to longevity of usage .

Fact is residing in my shed is my dads old saw he worked over some 30 years ago .That old Mac still cuts as good today as it did in 1980 .Actually better than it did factory fresh . Still starts on 4-5 pulls after sitting 6 months . Just one example but I'm sure there are more .

[Rocky_J]

But Al, changing anything on the saw will instantly void the warranty!!! 
Then it will die and I won't be able to do anything because the dealer will scold me for changing my own saw!!! 

 

[Al_Smith]

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