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chainsaw expansion chamber

Posted: Tue Feb 08, 2011 9:20 am
by ToddP
20 guage 304 stainless.

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Re: chainsaw expansion chamber

Posted: Tue Feb 08, 2011 10:12 am
by GWD
OK. I have several chain saws but can't imagine the use of that expansion chamber unless there was some serious porting and tweaking going on.

On the other hand, if the point is to demonstrate fabbing and welding skills it is quite impressive.

How about some more details on the performance gains and related facts.

Re: chainsaw expansion chamber

Posted: Tue Feb 08, 2011 1:06 pm
by ToddP
You pretty much hit it on the head.

I bought the saw to remove a big elm in my front yard. I grew up in the 70's and owned several 2 stroke motorcycles.

I just thought it would be cool to put an expansion chamber on a 2 stroke engine. The saw is very powerful out of the box for only 42cc.

It worked very well to fell this tree, so lack of power was not an issue for me. I also hope it sounds a little different when it runs

I have not run the saw yet with the pipe, so I can't comment on the performance increase/decrease. Saw is stock, no exhaust port mods.

I had a CZ motocross bike that had what they called a snail pipe. I tried to model the bends along these design ideas. I used a free internet program called java pipe to get some design parameters. They are based on exhaust port cross section area, displacement and rpm.

Also I used a program called cone layout to print unfolded patterens on a inkjet printer . The pipe is made from 23 cones. Lots of welding practice, as I just started doing tig welding with a used thermal arc ta 185 I picked up. Before all I ever used was a mig machine.
I stumbled on Jody's videos, and have learned a lot by viewing them and thought this pipe would expand my fabbing skills.

I am really happy with the TA185 and am also learning a lot about welding aluminum. Forums like this are great for noobs like me .

Re: chainsaw expansion chamber

Posted: Wed Feb 09, 2011 2:05 am
by jakeru
That is really cool; thanks for sharing. 20 gauge stainless = .036"?

Re: chainsaw expansion chamber

Posted: Wed Feb 09, 2011 12:19 pm
by ToddP

Re: chainsaw expansion chamber

Posted: Wed Jul 27, 2011 5:49 pm
by MACHINISTATLARGE
:ugeek: I have seen enough ( the video). "Orderly, fetch the nets and the coat with the extra long sleeves.". :twisted:

Off the wall, very warped, quite hilarious. Keep us informed of your future efforts. :mrgreen:

Pat

Re: chainsaw expansion chamber

Posted: Wed Jul 27, 2011 8:23 pm
by kermdawg
WOW that thing sounds exactly like a 2 stroke dirtbike :)

Hey how long did it take you to fab it up and weld it out?

Re: chainsaw expansion chamber

Posted: Sat Jul 30, 2011 8:52 pm
by Tritium
That video make me long for the days of my youth and a Honda Elsinore. :lol:

Thurmond

Re: chainsaw expansion chamber

Posted: Thu Jul 07, 2016 4:03 am
by Ez_Za
Thats awesome, wondering if you could give the details for replicating this?
Unfortunately i don't have time to strip down my chainsaw, and get the necessary measurements being the middle of winter.


Cheers