pipes

[mt.stalker]

Where do you guys get those expansion chambers ? There is so much theory,
etc. involved in building them. Way to complicated for this home boy !!!

 

[romeo]

You just try to get as much of the theory down as possible and start building them. So far the best theory I have found was my own through lots of trial and error. If you don't want to get into it there are a few guys out there building them for other people. The biggest problem I have found with most programs and formulas is that they are designed for bikes.

This might be the wrong way to do it but the best I have done is to copy some successful pipes (from pictures), threw in some trial and error, and came up with my own formulas. It will be tough to get someone to give you the answers your looking for.

 

[timberwolf]

So true, the material on bike pipes and also modle planes is as likely to lead you amuck as it is to help.

Rpm is different, port timing is different, temperature is different, and the power band needs of a race saw and a motor bike are different.

 

[saws43]

where in ontario are you I am also here and have built pipes

 

[timberwolf]

About 45 min west of Ottawa.

 

[cedarheaven]

Expainson Chamber

It's too bad Dennis hasn't responded to these threads as I know for fact that he has a software program which details every aspect of tuning an expansion chamber for each individual saw. Whether it be a Mac 101 or his racing saws. If your that interested look for the software program on your internet or motorcycle shop. I know one thing, it ain't cheap but it tells all; where to expand, contract and distance between each varible. I've been fortunate to have watched this program in action and if your that serious it's worth the bucks (BIG Bucks).

 

[timberwolf]

It is easy enough to calculate pipe dimentions without software, the numbers get worn off the calculator but it's not too bad and the pipes come out pretty close.

Calculating the cone layouts for simple cones is a bit more math intensive, I have found this manageable by inputing the calculations into excel and having the computer do the number crunching.

To make angled cones to form curves in a tapered pipe section is another whole level, but the end result is a much beter formed pipe.

Layout is everything, if you don't have a perfect fit between cones before starting to weld it is going to turn out like crap.

 

[J.Walker]

You just try to get as much of the theory down as possible and start building them. So far the best theory I have found was my own through lots of trial and error. If you don't want to get into it there are a few guys out there building them for other people. The biggest problem I have found with most programs and formulas is that they are designed for bikes.

This might be the wrong way to do it but the best I have done is to copy some successful pipes (from pictures), threw in some trial and error, and came up with my own formulas. It will be tough to get someone to give you the answers your looking for.

Could you explain how pipes work? Does the exhaust gas create a vortex in the expansion chamber which inturn pulls more fuel through to create more rpms? I thought that muffler mods helped saws run better by reducing backpressure, but pipes do what?
I need some schooling on pipes on saws so I can sleep better at night. lol
Thanks
J.Walker

 

[saws43]

So true, the material on bike pipes and also modle planes is as likely to lead you amuck as it is to help.

Rpm is different, port timing is different, temperature is different, and the power band needs of a race saw and a motor bike are different.

you may have had this offer before but you are the brains I am the welder can we work together?

 

[J.Walker]

you may have had this offer before but you are the brains I am the welder can we work together?

Saws43 No welding for you today... It's your birthday... Have a good day!

 

[J.Walker]

Could you explain how pipes work? Does the exhaust gas create a vortex in the expansion chamber which inturn pulls more fuel through to create more rpms? I thought that muffler mods helped saws run better by reducing backpressure, but pipes do what?
I need some schooling on pipes on saws so I can sleep better at night. lol
Thanks
J.Walker

Hey Romeo could you help me out, I just need to know

 

[rahtreelimbs]

Could you explain how pipes work? Does the exhaust gas create a vortex in the expansion chamber which inturn pulls more fuel through to create more rpms? I thought that muffler mods helped saws run better by reducing backpressure, but pipes do what?
I need some schooling on pipes on saws so I can sleep better at night. lol
Thanks
J.Walker

If I understand it right (anyone feel free to correct me here) it all comes down to the soundwave inside the pipe. When the pipe is built just right the soundwave will actually pull more fuelmix into the motor (and the pipe) and when the sondwave reverses (due to the cone shape, cone size and distance) it pushes the fuelmix back into the motor!


Think of an expansion chamber as a toilet plunger..............same basic effect!!!

 

[J.Walker]

Saw a old go-cart racer a few weeks ago. The muffler pipe had a slip cone at the end to add or take away from the pipe system. A different rpm point for the turns?
Thanks everyone for the help. I just needed to know.

 

[drmiller100]

the diagram can help some. theory can help some.

easiest is to find a pipe that works on a similar engine, and think about what each part does.

the headpipe doesn't screw up the pressure wave.
the diverging cone "sucks" exhaust out of the combustion chamber, and lengthens the charge wave.
the converging cone shapes the charge wave at least until the diverging cone reforms it.
the stinger sets static pressure in the pipe.

saw guys for the most part don't understand the stinger.

to figure turns in the pipe, measure the center of the pipe for distance.