Chainsaw Porting Theory

[Deets066]

Deets, I started out keeping note in a notebook.....but it was soon filled, then another...

I use Open Office now and keep my notes on the computer. Easier to find, and to add to as things change.

Haha, I don't ever plan to do near as many saws as you though

 

[Mastermind]

I by no means am looking for a magic recipe, but I however and I'm sure others like me may only ever grind on one saw and won't want to have to buy a new cylinder. They want to get it if not right then close. And having a basic understanding of what changes where can get you in the direction you are wanting to go is helpful. I for one have no illusions that I'm gonna build the fastest saw ever built, but I wanna make one I will be happy to run and if I make a mistake it's MY mistake and no one else's. My hope through this thread and other questions I have asked others that my knowledge base will expand and one day those mistakes will be less frequent.

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I think we have some really solid info on the site regarding porting theory. It's gonna keep getting better too.

 

[idiotwithasaw]

Most every post I make whether it's a question or an answer or thread I start my goal is to add to the knowledge and information here for others to find. I like to think that I'm not just asking for myself, but for someone like me down the road just as confused as I am now.

So I apologize if I ask a lot of what others might see as silly questions, but to some they aren't that silly, they are exactly what they are thinking.

Anyway ignore me and continue, a lot of good information here and I don't wish to impede the flow.

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[Al Smith]

Dave Nieger AKA "Big Dave" once told me he did't know any engine builder who didn't question his own work after the fact .It spite of how good it came out the question always arose,what if and how come .

 

[Mastermind]

Most every post I make whether it's a question or an answer or thread I start my goal is to add to the knowledge and information here for others to find. I like to think that I'm not just asking for myself, but for someone like me down the road just as confused as I am now.

So I apologize if I ask a lot of what others might see as silly questions, but to some they aren't that silly, they are exactly what they are thinking.

Anyway ignore me and continue, a lot of good information here and I don't wish to impede the flow.

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No question is a silly question.

Carry on.

 

[mt.stalker]

Popups give me vaginal soreness. Especially on Huskys.

Clean the sawdust out of your vjj , use some motul , It'll feel better in the morning .

 

[jmssaws]

Good read fellas.

 

[Magic_Man]

Well said Randy, I have kept some notes. But some of them are on paper towels, small pieces of paper, business cards, I've written on my bench too. I need to get a decent notebook to write the stuff down in.

I was the same way in my amplifier building and modding days. I have a pile of notebook scraps, backs of junk mail, etc. Unfortunately some of the best ones I did were never recorded. I would write down the base recipie but forget to note tweaks and changes I made before it left.

 

[Brush Ape]

Unfortunately some of the best ones I did were never recorded.

One of the earliest conspiracy theories guys has eventually been come to be known as, "The Hemingway Hoax." If you research it now with the advent of the net, you'll see things have escalated from the discussion as it once was. Now Hemingway's wife is vilified as somehow insidiously subjugating his carreer in a Paris train car handoff of his best work to the highest bidder in a James Bond-like scenario; the manuscripts yet to surface. I think there's a modern era Cuban or something now implicated in trying to forge something passable........the stuff of movies. However, at one time in the story as we were taught, he'd been on an expedition across Africa accumulating notes for months and lost them at the end when they sunk to the Nile River. He was forced to recreate the notes from memory and it became his most acclaimed work, (leaving that up to the reader.)

When I saw a bumper sticker in the 90's, which read; "When You Tell The Truth, You Don't Have To Remember What You Said;" I was reminded of the Hemingway saga. If you do something one-off, each time you have to pour over your notes and reconstruct it to make it a repeatable thing. When you grasp the theory, it becomes law in your mind at least through experience. That's where the rubber meets the road. And I'd rather meet the road with rubber than fresh pigeon poop. Too slick.

 

[Miller Mod Saws]

Looks like a thread I'm gonna haft to read when I get some time!

 

[Magic_Man]

When you grasp the theory, it becomes law in your mind at least through experience. That's where the rubber meets the road. And I'd rather meet the road with rubber than fresh pigeon poop. Too slick.

I would research and record the basic recipie. Once the amp was built I would use my knowledge and experience to tweak the sound to get what I wanted. Those tweaks are what I did not record. I guess honestly they are irrelevant, because each amplifier, like saws, are different. You can start with a basic recipie, but it takes knowledge and experience to get the end result your looking for due to these differences.

 

[Motorhead]

I would research and record the basic recipie. Once the amp was built I would use my knowledge and experience to tweak the sound to get what I wanted. Those tweaks are what I did not record. I guess honestly they are irrelevant, because each amplifier, like saws, are different. You can start with a basic recipie, but it takes knowledge and experience to get the end result your looking for due to these differences.

Had to read that a couple of times to get it.

 

[Brush Ape]

Yup, M_M I knew what you meant. And that's the beauty of valve amps-perfect sine waves rich in perpetual burn and laden with harmonics. Those aha moments with tubes usually have something to do with browning out.

 

[Motorhead]

Yup, M_M I knew what you meant. And that's the beauty of valve amps-perfect sine waves rich in perpetual burn and laden with harmonics. Those aha moments with tubes usually have something to do with browning out.

Lost me,

 

[beaglebriar]

How much can porting affect carb tune? How often are carb modifications or an upgrade necessary on a woods ported saw?

 

[Keith Gandy]

Yup, M_M I knew what you meant. And that's the beauty of valve amps-perfect sine waves rich in perpetual burn and laden with harmonics. Those aha moments with tubes usually have something to do with browning out.

My 2 favorites were a Marshall Bluesbreaker and a Mesa Boogie 50 caliber played on a Fender Custom Shop Strat Plus with mini humbuckers and coil taps that toggled between single coil and humbucker on the bridge and neck pickups

 

[jmssaws]

How much can porting affect carb tune? How often are carb modifications or an upgrade necessary on a woods ported saw?

Not much and not often.

 

[Deets066]

Depends on the porting if you go way low on intake, you will most likely be drilling the main jet

 

[riverrat2]

Excellent discussion.

I've been keeping notes since I first started porting saws. As I did more of the same models, I would update my notes to reflect changes to my "recipes". That has been the most valuable resource I have as a engine builder.

When a new model comes out, I start with small changes. Like .020" from the squish to see how much that changes the compression.

On the 661 I bought two new top ends before I learned what works, and how I wanted to do that saw.

That's just how it is sometimes. To really find the gains, you have to do some trial and error testing.

My suggestion is to always study the design. Then run the saw stock to get a idea of what it needs. For example, is it high strung, but lacking grunt? Or maybe it's strong, but lacks rpm...

Look at the design limitations. Like was said above.....how long is the piston skirt....how wide is it? Where are the ring ends? How long is the intake duration stock?

Most of the people that start asking me lots of questions are hoping for a magic recipe that fits every saw. That does not exist. Even different users want different things from the same saw.....

I can share every detail of my notes with another builder, but that doesn't mean they will get the same gains that I get. Port sizes, shapes, finishes, etc, etc. All these things matter to a certain extent.

freaking cat herders,,,, at it again!!!!

 

[wigglesworth]

Dave Nieger AKA "Big Dave" once told me he did't know any engine builder who didn't question his own work after the fact .It spite of how good it came out the question always arose,what if and how come .

One of the most intriguing saws I've owned was a DN 154SE. Wish I still had it. Made me wonder, that one did....