Filling cotton inside of muffler?

Good idea.

Very interesting topic. As well, I see both sides to the possible outcomes. Good for Mifflin, but at the same time, possibly bad for starving / choking the engine. I guess if it does hypothetically work, one may be able to replace the cotton between flights to keep it from getting overly saturated. As well, if it was me, it may be worth a shot at running it with different amounts of cotton.

Hello Levent, I would not   use cotton there, because on the one hand it will saturate quickly, it can get hot and it can even ignite by the engine's flame output from the exhaust port. You are at risk of fire.
Be careful with steel wool, if the threads are fine, it is also ignited by exhaust flames.
You must use metallic material, but thick enough in diameter so that it does not catch fire or melt,
If you want to silence the cylinder, use a perforated iron plate - steel belt, as some Cox engines originally came, and that will lower the noise a lot, although you will also lose some power.

Either of those two materials steel wool/cotton would end up being ingested by the engine.

The stock Cox muffler is pretty effective as is.

If you want lowes noise posible try sort of silencer try m'y way

I want to achieve a very quiet muffler. Thanks for answers.

I found flame resistant, square section cord. They are made from asbest or teflon and used for stove lids. Perhaps it works.

Hi David, I want to make it more compact, without a silencer. Thanks.

Like this:


https://www.lenehans.ie/vitcas-stove-fire-rope.html

Maybe fill it with some sort of fiberglass? (Insulation, tape, something like that), but as noted before, it could get sucked into the engine.... how to retain it...

Hi Levent,
If you can find window screen made of aluminum you can try cutting a strip of it, roll it up to be able to fit in the muffler. The many layers would help disperse the sound waves without creating too much back pressure.

Dirt bike use som sort of like that stuf we call in french laine d'amiante its pact in last parts of the tune called pipe its silencer and its Not obstructed al around the tube wit lots of hole tink if u try that Not going To work use just smaler tube od inside the exaust wit lots of smal hole and dril in the exaust couple more hole Not as mutch like the one inside and it wil work sure dont fil the gap wit that stuf very bad if the engine ingestion if y was u y try Somting difrent

Folow coxadict Good solutions coper screen To wil have chance To work dont use coton

coxaddict wrote:Hi Levent,
If you can find window screen made of aluminum you can try cutting a strip of it, roll it up to be able to fit in the muffler.  The many layers would help disperse the sound waves without creating too much back pressure.  

Very good idea

The smaller the holes,the faster it will plug up with exhaust residue and gag the engine.  We constantly had to burn that crap out of plugged up Moped exhaust systems with a torch so they would run again!

When i attempted my amazon rc boat with a cox, i made an underwater exhaust for it, but when i would start it outside the water, i noticed lots of noise came from the engine itself and not all from the exhaust.

MauricioB wrote:Hello Levent, I would not   use cotton there, because on the one hand it will saturate quickly, it can get hot and it can even ignite by the engine's flame output from the exhaust port. You are at risk of fire.
Be careful with steel wool, if the threads are fine, it is also ignited by exhaust flames.
You must use metallic material, but thick enough in diameter so that it does not catch fire or melt,
If you want to silence the cylinder, use a perforated iron plate - steel belt, as some Cox engines originally came, and that will lower the noise a lot, although you will also lose some power.

'
I'm pretty sure the cylinder in photo was an early version designed to prevent fires.

Packing course steel wool has been used by modelers for years, not a big gain and why you'd bother, but not unheard of.

getback wrote:I think it will become wet with exhaust castor and choke the engine down / maybe loose steel wool?

Yea! that's it! steel wool.. or fiberglass stuffed in the header-pipe(s).. "glass-packs"..  ...... I'll try running some in my header-pipes.

edit; the exhaust-oil will drip-through the header; creating an acoustic-cushion (remember extrude-hone?) for the passage of the exhaust-note(s).. and drip-out of the pipe(s).. unless a sump is devised. Collecting/containing exhaust-oil wastes could help promote the further use of IC model engines at the flying-clubs.

What about a muffler like that MauricioB has?
It an old Tatone muffler and it look like a muffler like for bigger engines?

sosam117

MauricioB wrote:A good friend a long time ago gave me this accessory, because it must be something interesting to use, although when I do, I will put a pressure pressurizer for the fuel tank.

I've used this stuff in small stationary engine mufflers before. Just a common pot scourer.

It is best to try a rolled strip of fine screen mesh inside of muffler as coxaddict suggested.