Expansion Chamber

[064 stihl]

Will painting a expansion chamber effect it?

 

[MasterBlaster]

My guess is no.

But I'm just a climber.

 

[ccicora]

It will burn off the paint if you use the wrong paint or flake at the welds if it is brassed. I would just add freash coats as needed. As for the smoking problem use stove paint.

Later,
Chris

 

[Lawn Masters]

Using a stove paint works to solve the issue of the paint just burning off pretty quickly, stove paint is made to withstand the heat of a hot fire that burns at temps way higher than a saw will ever reach normally.

BTW: what is an expansion chamber? I've heard of them but dont know anything about them. what does one look like, and what does it do?

 

[rmihalek]

An expansion chamber is a special exhaust pipe that is designed to make a chain saw very loud. This way, your co-workers in the woods can hear your saw running and know when to get out of the way of the tree you're about to drop. There's an old expression among loggers: Loud Pipes Save Lives.

 

[Lawn Masters]

now I misunderstand completely, I now get the picture with more clarity and logic. Thank god, now I know what an expansion chamber is.

 

[ray benson]

Believe this has been posted before- expansion chamber
http://www.arboristsite.com/showthread.php?s=&threadid=1869&highlight=expansion+chamber

Ray

 

[glens]

Originally posted by oldsaw-addict
BTW: what is an expansion chamber? I've heard of them but dont know anything about them. what does one look like, and what does it do?

The first part of your post notwithstanding, your question does merit a response.

An expansion chamber is a two-stroke engine device which uses shapes and sizes of exhaust plumbing designed to specifically address the problem of fresh charge escaping the combustion chamber prior to the exhaust "valve" closing, thus being wasted.&nbsp; Construction is basically like two funnels, large ends facing each other, connected by a chamber often shaped like a well-fed largemouth bass.&nbsp; At design frequency, temperature, and density of the exhaust gas pulses, the sonic pressure wave created when the exhaust "valve" opens is harnessed and timed to reflect back toward the exhaust port, pushing back into the cylinder the new, fresh charge that has just escaped out the opening.&nbsp; It's similar in result to a forced-induction system (supercharger or turbocharger) in that, though to a lesser extent, <i>more</i> fuel/air mixture ends up in the combustion chamber than would "normally" be there.&nbsp; Rather like free power; but really just increasing efficiency in this case.

A thousand words are worth a picture.

Glen

 

[ehp]

064 paint does not hurt your power on a pipe but if you are running gas your pipe does get alot hotter than if you are running alcohol so your paint may bluster at the header

 

[Typhoon]

Was getting ready to answer that, but Glens said it perfectly!

 

[064 stihl]

Thanks for the info. Thats what I wanted to know was about the power.

 

[cybergeek23851]

Sorry to drag up an old thread but, while sitting here at my computer today, I decided to design my own expansion chamber. It is just a very basic design ( give me credit, I'm new to this), and I wanted to know what I could/should change, and overall just give me some feedback on it. Sorry about the spelling mistake in the pic. It's a new (to me) cad program.

 

[ehp]

well here is my 2 cents, take it or leave it.
first by your picture it looks like your are using a 0 degree header , they work but 2.7 to 3.2 degree taper header works alot better , you will have more torque with the tapered headers,
it looks like you donot have a dwell section in your pipe , it is the big centre section that is flat in the middle of the pipe, i know some designs donot use them but i find the pipes with them work better , just my 2 cents

 

[cybergeek23851]

Thanks. I've never designed one before, and I just designed it out of boredom this morning. I also realize that it was lacking the angle there. The program is new to me and I am having to re-learn CAD design. If I was building it, I would have included that in the design.

 

[ehp]

if your design is correct then building a pipe is no big deal , but you need the numbers to work before you start cause trying to get the pipe to do what you want after you made it by cutting here or there usually makes a big mess

 

[Al Smith]

Expansion chambers[tuned pipe]

My old bud,I went to apprenticeship school with,was a national ranked Kart racer,in the 70's.He used mainly,101 piped McCullochs.He had a special pipe that could be adjusted,by 1/4" increments,for temperature ,track conditions etc.[ changed the "sweet spot} on the engine.Worked very well for him,but alas,he has not one Mac part left.

 

[cybergeek23851]

I realize that there is a lot of science behind it, I just designed it based on some of the designs that I had seen in the past.

 

[ehp]

There is nothing wrong with trying different stuff, that is how you make gains , just because someone tells you that is the way it is to be done , that should not stop you cause you may figure out something that the others have not, nothing is writen in stone and around ever corner there is a better wagon wheel

 

[jokers]

Originally posted by ehp
if your design is correct then building a pipe is no big deal.....

Well here is what is probably a stupid question, but do you roll your own cones and cylinders or is there a place to buy the sheetmetal preformed?

Thanks, Russ

 

[ehp]

Russ I cut my own cones, I have a small roller that the rolls are 1 inch diameter, but still i use my hands alot to shape the pipe, it is not as hard as most people would want you to believe on building a pipe as long as the volume of your pipe is correct for what you want to happen, 99% of building a pipe is done before you ever cut a piece of metal, welding it together is not that hard just takes time, the one I build are ,
the header is 18 gauge,
diff, dwell, baffle and stringer are 24 gauge