Packing a muffler, wire wool or wadding

[Sutol]

Started to make the new muffler for the tractor as the factory horizontal box with a little pipe facing forward was rotten.

The chrome pipe is inch and a half and the muffler is tree inch tube, just had it hanging round in the garage.

What hould I pack it with do you think.

Needs to be cheap, cant afford any fancy special stuff

 

[Jeff Lary]

When I was in voc school I made one for my 100cc dirt bike I took the pipe and drilled a bunch of 1/4 holes in it ,Then I slid it into the shroud section which was about 2" bigger than the pipe.I then stuffed the space in between with single ought " O " steel wool then capped the other end when finished. Sounded pretty good.
I welded the end cap on before I started the bike so I could not have made any adjustments that was a mistake,... as I should have removed a little bit of the steel wool it seemed a little restricted to me. So untill I ran the unit I would not weld the end on ,that way if ou need to add more or take some out you can.

 

[Sutol]

When I was in voc school I made one for my 100cc dirt bike I took the pipe and drilled a bunch of 1/4 holes in it ,Then I slid it into the shroud section which was about 2" bigger than the pipe.I then stuffed the space in between with single ought " O " steel wool then capped the other end when finished. Sounded pretty good.
I welded the end cap on before I started the bike so I could not have made any adjustments that was a mistake,... as I should have removed a little bit of the steel wool it seemed a little restricted to me. So untill I ran the unit I would not weld the end on ,that way if ou need to add more or take some out you can.

Mmmmmm, mine is to be padded only around the inner pipe so as it is straight though, hopefully the noise will be absorbed via the half inch holes and muffled by the padding

Edited because I missunderstood reply (old person) was it too quiet then even though it was straight through?

 

[westcliffe01]

What you want is fiberglass ROVING. You buy it on a roll (like an oversized cotton reel) and you peel it off that and stuff it into the space between the inner and outer tube.

I don't recommend holes bigger than 1/8" and it may be better if they are smaller (more work to drill). Keep the length of the tailpipe (from where the holes end to the end of the exhaust pretty long (20-30")) else it will have a "bark" to it. It helps a lot if the end is directed away from the operator (sounds obvious).

The steel wool will be corroded away in a few weeks, unless you can get stainless steel wool which is much harder to come by. Generally, unless the volume of the chamber is several times the engine swept volume, it is only going to take the edge off. Thats the way it is.

 

[Sutol]

What you want is fiberglass ROVING. You buy it on a roll (like an oversized cotton reel) and you peel it off that and stuff it into the space between the inner and outer tube.

I don't recommend holes bigger than 1/8" and it may be better if they are smaller (more work to drill). Keep the length of the tailpipe (from where the holes end to the end of the exhaust pretty long (20-30")) else it will have a "bark" to it. It helps a lot if the end is directed away from the operator (sounds obvious).

The steel wool will be corroded away in a few weeks, unless you can get stainless steel wool which is much harder to come by. Generally, unless the volume of the chamber is several times the engine swept volume, it is only going to take the edge off. Thats the way it is.

The chamber is at least twice the swept volume I would say, maybe more. Its only a small two cylinder machine and wasn't too bad with just a pipe on it, need to take the crack out of it and dull it down a bit.
could block the pipe so that the gases have to exit the pipe into the chamber then back into the pipe higher up passing through the wadding.

I'll have to buy some wadding, dont want to but seems the best idea as the muffler will outlast the tractor as it is all thick wall pipe.

 

[otis whitehead]

Here in the states we have this stuff called "Brillo" pad. I think they have a stainless version of it. Its a pot scrubber for the kitchen.

 

[Sutol]

Here in the states we have this stuff called "Brillo" pad. I think they have a stainless version of it. Its a pot scrubber for the kitchen.

Yea we have Brillo pads as well, I think I have also seen stainless scourers without soap in the cheap shop, two in a pack.

Great idea.....thanks

 

[Jeff Lary]

Mmmmmm, mine is to be padded only around the inner pipe so as it is straight though, hopefully the noise will be absorbed via the half inch holes and muffled by the padding

Edited because I missunderstood reply (old person) was it too quiet then even though it was straight through?

Yes I ment the space berteen the two pipes as well not the interior of the exhaust itself.

 

[The Haymaker]

Moose Racing Competition Muffler Packing - Dirt Bike Motocross - Motorcycle Superstore

 

[Craig Clayton]

I have been reading over the other postings. The way I understand a muffler it is much like a expansion chamber. The individual exhaust blasts enter and they buffered to hit on the next blast with the effect to kill the loud boom to each other.
All the gas that goes in must come out. Expect it comes out in a smooth flow.

A silencer on a gun ( TV only knowledge ) collects that sonic boom of expanding gas and kills it.

I would go to a muffler web site and see what they claim their internal parts look like.


Craig Clayton