Noise-noise-noise

[loquin]

Well, I tried the temporary setup with the tubular muffler.

It appears to be slightly louder than the pancake style, but, I like the way it sounds more. It's a little deeper sounding, 'throatier' muffler. The high pitched popping noises are just about gone.

Once the permanent setup is in place, I can swap the mufflers out easily, to get a better feel for which one works best...

Here's how I think I'll need to mount it. (ref the attached sketch)

I'll need to add a short piece of aluminum angle, to extend the friction drive channel, then, fasten the flange ell to the angle. The sketch is in two parts - the top half is a top view of the 'Plumbing' between the existing muffler and the flange ell. The bottom half is a side view of the remainder of the 'Plumbing,' between the flange ell and the adapter. Either muffler can then just thread into the adapter. I'll use a short section (less than 2 inches long) of the silicon tubing, along with a second hose clamp, to hook up the entended exhaust pipe to the existing muffler.

 

[Stink Bike]

I'm excited!
It looks like you have the noise problem solved.
Great work.
What type of motor have you fitted it to?
Could you show us a photo of you finished work.

Mick

 

[loquin]

It's going on a Mitsubishi TLE-43, on a Staton friction drive. The manifold is done & painted. When it's dry, I'll post a photo of it. As well as installed.

 

[loquin]

Here we are. The first pic is of the exhaust pipe, ready to install.

The next two are the as-installed pictures.

Now, it's not as quiet as it was I was testing the configuration. (The test configuration was using a 2 ft. section of copper pipe, as well as the entire foot-long section of silicon hose.) I believe that this extra length was 'tuned' for a lower frequency than the bulk of the engine sound output. It's still substantially quieter than without the extra plumbing though, so I'm going to stay with it.

 

[Hive]

With Smaller MOtor

I went a little smaller, but have to wait to test...details in other thread.

 

[larymor]

I tried Lou's muffler idea on my 4 sroke Robin/Subaru and it is not worth the effort on this engine....made such little difference it is not worth doing. Just a heads up for R/S or other 4 strokers.

 

[Hive]

I Agree

The added muffler idea is not worth the time. You can see more here: http://www.motoredbikes.com/showthread.php?p=113108#post113108

We have spent some time and money and saved others some time to apply elsewhere.

Have copper mesh for sale... :]

But, I do think that if the muffler was attached directly to the engine, by removing the stock muffler box and using an adapter, the results might be different.

Simple is always best.

Amen to this project.

 

[loquin]

I haven't spent quite enough of either yet, Hive...

I DO agree, that small and noise reduction don't go together, though.

My results were promising. As it, the one I built reduces noise levels enough to use it. But, there's a couple more avenues to check out before I'm done.

 

[ptglass]

Here's a somewhat wacky idea for you. Has anyone thought of using a small oil filter for a muffler? I saw where someone used an oil filter as a silencer on a gun. Just use a hole saw to make a hole in the opposite end and thread the other end on a piece of pipe and connect it to the engine. Never tried it, but it might work.

 

[loquin]

They use a heavy filter paper on the inside. It would catch on fire after a while, & poof! Your baffling goes up in flames. It would add some extra realism to a custom flames paint job, though!