Thread Tools
Jan 11, 2020, 02:21 PM
Registered User
Thread OP
Discussion

Muffler packing


I remember back in the day that lots of engines used muffler packing to quiet and change the tone of the engines in everything from cars to lawn mowers. Now I see that most 2-stroke dirt bikes have a special chamber to stuff with packing for tone and as a spark arrestor. I was just wondering if that stuff could be used in gas 2-cycle mufflers to tone them down. Lots of people complain about the noise and how to reduce it. Just wondering.

https://www.amazon.com/s?k=muffler+p...b_sb_ss_i_5_15
Sign up now
to remove ads between posts
Jan 11, 2020, 02:32 PM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by JimboPilotFL
I remember back in the day that lots of engines used muffler packing to quiet and change the tone of the engines in everything from cars to lawn mowers. Now I see that most 2-stroke dirt bikes have a special chamber to stuff with packing for tone and as a spark arrestor. I was just wondering if that stuff could be used in gas 2-cycle mufflers to tone them down. Lots of people complain about the noise and how to reduce it. Just wondering.

https://www.amazon.com/s?k=muffler+p...b_sb_ss_i_5_15
There are lots of ways to quiet down sound. However you can't just stuff the packing in our typical muffler and expect it to work. You still need a good pathway for the exhaust gas to evacuate or you will lose a lot of power and choke up the engine. The idea behind quieting down the sound is to slow the exhaust gas by diverting it. The process result in additional weight.

The pattern flyers were about the best in quieting down their engines back in the mid 1980's. They did ok to some extend but the whole idea was not very successful because not only does the engine makes noise the propellers were making a lot of noise. So the long stroke 2 cycle engines came about to slow down the RPM. Then by 1987 the 4 stroke engines came on the competition scene and the rest was history.

It is all a big compromise of a lot of variables. Just stuffing packing will mitigate one area of the entire noise issue but will not resolve the total picture.
Jan 11, 2020, 03:15 PM
Still gassin' it.
Of course it can be done, but you need to have a muffler that can be opened up and boxed again at will, because you will be exchanging that packing stuff regularly. It tends to clog up from the residues caused by the oil in the fuel.
Jan 11, 2020, 03:19 PM
Registered User
Thread OP
Those gas engines are especially loud and the mufflers don't do much to reduce it. Most of the Gas mufflers seem like the Pitts type and are little more than a manifold with two pipes hanging down. I know all about 'can' mufflers and just thought some folks might could use some packing to help them. All the dirt bikes have them. Brass wool maybe??
Jan 11, 2020, 03:21 PM
Still gassin' it.
I don't know if Zimmermann mufflers from Germany are availlable in the US? They are brilliant (quite literally), beautiful, and don't use packing.

https://zimmermannschalldaempfer.de/
Jan 11, 2020, 03:32 PM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by 1967Brutus
I don't know if Zimmermann mufflers from Germany are availlable in the US? They are brilliant (quite literally), beautiful, and don't use packing.

https://zimmermannschalldaempfer.de/
They are. I still have one for my gas helicopter. Still very noisy though.
Jan 11, 2020, 03:36 PM
Still gassin' it.
Quote:
Originally Posted by SeismicCWave
They are. I still have one for my gas helicopter. Still very noisy though.
??? Noisy??? A Zimmermann? They are usually quieter than anything out there. Most Zimmermanns, even the tuned pipes, focus more on noise reduction than performance increase.

My gasser heli's were very acceptable with Zimmermann (they were subcontractor for Vario and made most of their model-specific exhausts).
Jan 11, 2020, 03:44 PM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by 1967Brutus
??? Noisy??? A Zimmermann? They are usually quieter than anything out there. Most Zimmermanns, even the tuned pipes, focus more on noise reduction than performance increase.

My gasser heli's were very acceptable with Zimmermann (they were subcontractor for Vario and made most of their model-specific exhausts).
Well noise level in many ways is objective. I am hard of hearing and I actually want my plane to be noisy so I can hear it now. However one of my neighbors did walk over when I was flying my gasoline powered Xcell with the Zimmermann muffler and commented about it was noisy. Then again he is no longer my neighbor and was a strange person. Another story is that the Zimmermann actually came loose and the sudden noise increase startled me into a rather hard landing on an inclined surface and had a rotor blade strike the ground.

I have another muffler (aluminum, lighter but larger) from Century helicopter and the noise level to me was not much different between the two.

Gas engines are noisy. However some of the Bisson mufflers actually put a "growl" into the gas engines which make rather neat sound. The problem with quieting the noise level has always been weight.

I have a muffler here that I use on my Super Tigre ST3000 when I do test at home. I believe it is made by J'Tec. They adapted two muffler to the end of a chamber and call that the snuffler muffler. The two mufflers are from the gardening equipment. Made of steel and pretty heavy but very quiet. I have no idea what kind pf packing material or construction is like with the mufflers since they are not easily taken apart.

http://www.jtecrc.com/snufflermufflers.htm
Jan 11, 2020, 03:48 PM
Still gassin' it.
Gasser helies are going to be loud, no matter what you do, it's the nature of the beast. But the Zimmermann mufflers in my experience are the "go to" if you want quiet off the shelf. The only thing I know that can be quieter is home made. If you know how and what to do (which I do not know… not really).
Jan 11, 2020, 03:50 PM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by 1967Brutus
Gasser helies are going to be loud, no matter what you do, it's the nature of the beast. But the Zimmermann mufflers in my experience are the "go to" if you want quiet off the shelf. The only thing I know that can be quieter is home made. If you know how and what to do (which I do not know… not really).
LOL, we are both online and typing. Look at the snuffler muffler. I guess they can be adapter to helicopter use for close quarter flying. I wouldn't want to use them on an airplane because of the weight. I wouldn't use them on a heli that is weight sensitive either.
Jan 11, 2020, 07:33 PM
Registered User
Quote:
Originally Posted by 1967Brutus
Of course it can be done, but you need to have a muffler that can be opened up and boxed again at will, because you will be exchanging that packing stuff regularly. It tends to clog up from the residues caused by the oil in the fuel.
That they do. I don't know if you remember the old pass-through glass pack mufflers (they still use them today). But when you first installed them, they were quiet as hell. You had to wait for the carbon to stoak up the fiberglass packing, to develop a more throaty sound out the pipe. In a model engine, the oil would chock up the packing fairly quickly.
Jan 11, 2020, 07:53 PM
Grumpa Tom
Kmot's Avatar
I have done it and yes it does quiet the engine down and does not make a significant power loss, for a sport plane anyway. I used the large mesh stainless steel scrubber pads and just cut them up and used enough to pack a muffler.

https://www.amazon.com/Products-Extr.../dp/B01B5BXHF2
Latest blog entry: My new AT-6
Jan 11, 2020, 07:59 PM
Grumpa Tom
Kmot's Avatar
The camcorder microphone did not make the sound level difference as noticeable as it was in person.

GMS 76 Muffler Comparison (2 min 44 sec)
Latest blog entry: My new AT-6
Jan 11, 2020, 08:39 PM
Registered User
earlwb's Avatar
For gas engines you pretty much have to go with canister mufflers to reduce the engine noise. The little small mufflers just cannot be quieted much if any. Yes you could add some baffles or stuff it with atainless steel wool, but it just won't work as well as a canister muffler will.
Latest blog entry: yes I still fly airplanes too
Jan 11, 2020, 09:10 PM
Play that funky music right
kenh3497's Avatar
Quote:
Originally Posted by ClubFlyer
That they do. I don't know if you remember the old pass-through glass pack mufflers (they still use them today). But when you first installed them, they were quiet as hell. You had to wait for the carbon to stoak up the fiberglass packing, to develop a more throaty sound out the pipe. In a model engine, the oil would chock up the packing fairly quickly.
I used to "fill" them with oil before installation. They would smoke like hell but the "fire" would burn out the glass making them loud from the get go!

Ken


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Making 3 cell Li-Po pack from two salvaged 2 cell pack... Delicate operation ??? woodylepic Batteries and Chargers 4 May 05, 2016 04:59 PM
Discussion Saddle pack vs single pack jester_s1 Off-road Cars 7 Mar 02, 2016 10:36 AM
Discussion CHARGING DJI PACKS and NON DJI BATTERY PACKS AVAILABILITY shredmandan Multirotor Drone Talk 2 Jan 09, 2016 12:32 PM
Discussion Multiple Smaller Packs in Parallel or One Large Pack? daBKLYNdoorman Batteries and Chargers 10 Dec 08, 2015 01:34 AM
Discussion Making a 2s pack from 2 1s packs Devedander Batteries and Chargers 1 Nov 06, 2015 04:08 AM