STEVESRCWORLD

My Feedback: (23)

i have a warbird that i am currently building and i am installing a 26cc size engine. i want to take the stock exhaust off and make a open header and let it run out of the bottom of the cowl or angled back. will it effect the way the engines run's? will it make more or less power? i am a welder and machineist and have access to aluminum tubing and all the parts to do so. but i don't want to adversely affect my engine. thanks

mogman

Do you fly with a club, or out in the boonies somewhere? Noise is a BIG issue at a lot of fields and a lot of sites have been lost due to noise.
Just something to think about. A straight pipe will be noisey.
Cheers, Dave.

Tired Old Man

My Feedback: (1)

Performance wise it probably won't be much different than with a stock muffler. Perhaps even a little better performance. Conventional wisdon is that a two stroke requires some back pressure to perform well but if the pipe was long enough or had a bend or two in the right places it would work. Noise will be somewhat louder but not as much as most would expect. Stock mufflers really don't "muffle" very well.

Charley

My Feedback: (2)

What engine is it? What kind of muffler does it have? Without this info it's impossible to make a judgment. Some "muffle" better than others and present more restriction to flow.

My suggestion is to run it on the bench to get a feel for its performance and noise quotient. Then, since you have the skills, make up a muffler system that fits, run it with this on it and compare notes.

Just remember that noise is our enemy!

CR

BaldEagel

Had to jump in, its just very nice to see at least a couple of people talking sence about noise issues and the fact we should keep them down, more power to you chaps.

Don't muffle silence.

Mike

STEVESRCWORLD

My Feedback: (23)

i beleive you guy's are right. i think i will just leave the factory muffler on. it is a xyz 26cc engine. the muffler look's like a weedeater muffler with a single outlet on it. just for curosity. what size straight exhaust would be bood for this size engine? 1/2, 3/4 or what?

Charley

My Feedback: (2)

Since you just don't get it : 1/8" !

CR

Tired Old Man

My Feedback: (1)

1/8" is definately is not.

I fly at a few places where noise is not ever an issue, and probably won't be for a decade or more to come. Now I'm fully aware that there are noise nazis out there just as there are smoking nazis, and alcohol nazis, but has anyone contemplated that this person my not have any type of noise issue where he flies? There are still open spaces in unpopulated places in this country yet.

I'm only guessing but I have a feeling that he knows what will work without a problem where he's at.

altavillan

My Feedback: (1)

The port timing of the enginewill tell you how long the exhaust header needs to be for best power and response. I have engines that need 9" and engines that need as long as 14". I would think you would want the exhaust at least 6" long so cool air can't get into the cylinder too fast after shut down. Make the header from a size pipe that will be compatible to a cannister/tuned muffler when you get tired of the sound. AI or Mack's would be places to look. You'll just have to experiment with lengths.

STEVESRCWORLD

My Feedback: (23)

YES I DO GET IT! since i own 150 acres that will never leave my family, i'm pretty sure that if the deer and squirrels start complaining then i'll change it.since i am the president,secretary,safety officer and noise police at my club then i'll worry about what happens here. if you don't have anything to say about what i am trying to experiment with. then turn the channel. thanks pat for your help. you're the best.

khodges

My Feedback: (1)

Measure the diameter of the stock outlets and calculate their area. Then take a single tube that is closest to this. Make it longer than you need by 6 inches or so. Mount it to the engine, test run it and measure rpm at mid to WOT. If it's okay, leave it alone, if not, shorten it in increments and retest at each increment until you get the performance you want. Put whatever bends you need in before you start shortening it.

Noise isn't really the problem. People complain because they know you're having more fun than they are.