@#$% box muffler...

[zopi]

Just welded up that stupid muffler on the kohler fifteen for the third time...sucker cracks out at the inlet pipe....this time I did it in the premise that the bigger the glob, the better the job...
Next time I am just going to build a bloody muffler which does not suck.

Stupid design.

Wonder how hard it would be to power an Lt fifteen with a 1200 sportster engine.... . Sure would sound good.

[r.man]

I've also wondered if all small engines should have vertical tailpipes to put the exhaust away from the operator. Between lawnmowers, snowblowers and chainsaws I seem to be eating a fair amount of exhaust these days.

[zopi]

The exhaust blows away, but for ninety bucks to replace...what a piece of crap. Love the engine...hate the muffler...

Was thinking of taking a piece of driveshaft and lining it with glass mat, running a center tube through with a cutout and welding the sucker shut...ever see a woodmizer with glass packs? Lol...lake pipes...

[Don_Papenburg]

Forget the fiberglass . use a waterpipe (scd. 40 ) point it up ,cut to length .  longer =quieter
scd.80 will be mellower than 40
forget that all and put the sportster engine on it and run the straight pipes.

[zopi]

Neighbors would love that on a sunday morning...

We used to build truck mufflers when we could not find what we wanted...two pieces of driveshaft, inlet and outlet...drilled around, sheet steel box around with a baffle down the middle...they sounded pretty good...
I am more concerned with the lever arm versus vibration...'s why this bugger cracks out....next one is just going to be a tube and baffle with an uptake pipe...and as quiet as I can get it...
Took that stupid cage off too...I think all the weight of it was the biggest problem.

[Dewey]

I had the same problem with my 27 HP Kohler...  I solved it by bolting two muffler clamps to the top of the motor and clamping the verticle pipes so they don't vibrate back aned forth.... I havent had a problem sence   

[zopi]

By and large, that muffler is my only complaint with the mill...or the engine for that matter...
Aside from the fact that it is not a diesel...

[Brad_bb]

It is frustrating how loud some of these engines are.  Why don't the manufactuers have mufflers that seriously quiet them down?  I mean, guns with silencers really do the job.  This is one thing I've thought about when I buy a mill soon.  I want that engine quieted as much as possible.   How??

[r.man]

I once stuck a car muffler with a pipe on both sides right over the muffler of an old generator I was running to work on a building. That thing was driving me crazy and deaf in that order before I stuck the old muffler on it. It was downright quiet after that. I have often thought that small motors should have big mufflers that exhaust as far away as possible. Bad enough to be eating sawdust without exhaust gas thrown into the mix.

[eastberkshirecustoms]

It is frustrating how loud some of these engines are.  Why don't the manufactuers have mufflers that seriously quiet them down?  I mean, guns with silencers really do the job.  This is one thing I've thought about when I buy a mill soon.  I want that engine quieted as much as possible.   How??

It's pretty much 'accepted knowledge' that most huge, quiet mufflers are also restrictive to exhaust flow. While this is good for your ears, it also hinders power and economy. I believe the manufactures are trying to squeeze as much power and economy out of the small engines of today, so they have to balance this with the decibel output.

A gun 'silencer' reduces power output also and is actually a suppressor that requires the projectile to travel slower than the speed of sound, otherwise the muzzle crack will just occur at the end of the suppressor, making it useless. . The slower projectile will have less velocity than an unsuppressed equivalent. 

You ask how, well there are electronic noise canceling systems that read the exhaust note and 'bombard' the flow with directly opposite sounds- effectively canceling out all the sound produced. You could have a theoretically quiet exhaust with no restriction, but at a cost $$$.  

[Slabs]

A few years ago my neighbor was running an aincent Scag mower with a 18 Kohler.  The muffler had completely disintegrated and he was blowing out of a couple of stubs.  I made two flanges to mate the exhaust ports,  added a few inches of 3/4 inch conduit and half of a 3/4 inch coupling to each pipe and flange assembly.  Two 3/4 inch generic lawn mower mufflers and we had a fine set of rack-off pipes.  Had a fine little bark as he sped around the yard like a wild Indy racer.  It was one of the vintage Scags with the one'wheel sulky seat behind and he really liked to hot-rod it.

[5quarter]

Brad...you might want to consider an electric motor. You can lose up to 20% of your HP trying to keep your engine quiet. A mid-sized mill won't be any louder really than a riding lawnmower. I wear both ear protection and a face shield when sawing anyway, so the noise is not a factor for me.

[Brad_bb]

I think you can still reduce the noise without restricting the flow.  You need to absorb the sound waves before the leave the area of the engine.  That could mean sound absorbing panels, or redirecting the sound in the direction you choose.  When I get one, i'll have to do some experiments.

[Ianab]

One of the tricks is to create multiple "paths" through the system. This means the exhaust pulse arrives out the outlet spread over a period of time, and so is "muffled", it loses it's sharp crack, and the engine develops more of a "purr".

Of course to do this you have a much larger and more expensive muffler. Now if it's a top of the line BMW, you pay $5,000 for the exhaust system. With a small industrial engine, they use the minimum that OSH will let them get away with, and that usually means restricting the exhaust to quieten it, even if that means a loss of power.

Ian

[Old Hilly]

It's no great problem to adapt an automotive muffler to a stationary engine, once you work out where to put the muffler and how to connect it to the exhaust port. If space isn't a problem then you can hang the muffler almost anywhere where it won't get in the way. The old Briggs motors used to have a 3/4" waterpipe thread in the block to screw a "muffler" into. I used to replace this with a steel plumbing bend and fit what used to be called a "hot-dog" straight-through sports muffler. This brought the exhaust note way down but there are so many rattles and other noises that come out of air cooled engines that they are still noisy. This is one reason that motorcycle engines are mainly all liquid cooled down here in OZ, it makes them quieter and easier to get compliance for on-road use.
If the Govt. brings in noise controls for small engines you can bet that we will see liquid-cooled engines come on the market really quickly. Just don't ask about the price unless you have had your Heart medication first.

[Magicman]

I want that engine quieted as much as possible.

Sadly, much of an engine's noise comes from the engine itself, not the exhaust.  Since a sawyer is so close to the running engine, ear protection is a requirement.  

[millwright]

When I got my old lt30 it had a broken muffler, I took the pipe out of the 14 horse kohler and bought the smallest car muffler I could find and welded it to the pipe, it worked great and didnt seem to have any power loss.

[zopi]

@#$% muffler...still really getting used to the trailer...stepped up on the mill to reach across and kill the water and put my hand right on the bloody muffler...lets just say that it does not take me long to look a muffler over..

[Slingshot]

    "Took that stupid cage off too...I think all the weight of it was the biggest problem."
     ______________________________________________________________ 
   

      Sometimes we just can't win.



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[zopi]

Believe me, that is the first...uhhh...second thing I thought.
Cannot post the first thing I thought.