Muffler packing material? What to use?

[ebinmaine 63,081]

I've been considering making my own muffler out of a particular piece of chrome pipe I have on hand.

I think I've come up with the idea for the basic structure okay.

1.25 inch tube with Bunches of holes set into the 2 in chrome tube.

 

My biggest question is what to use for packing in between the two tubes.

 

 

[SylvanLakeWH 24,118]

[littleredrider 408]

You can buy the material prolly from evilbay or amazon. Buddy did one with fiberglass insulation, Dunno what the dangers of that would be, but Im curious as well, I have a roll downstairs and gonna have leftovers lol....

[littleredrider 408]

https://www.amazon.com/fiberglass-exhaust-packing/s?k=fiberglass+exhaust+packing

[Achto 26,545]

I used fiberglass mat when I made the pipe for Radpferd. The same fiberglass mat that is used for making repairs on fiberglass.

 

 

Edited May 11, 2020 by Achto

[ebinmaine 63,081]

48 minutes ago, Achto said:

I made the pipe for Radpferd

Does the exhaust go THROUGH the fiberglass or did you use that only as a sound deadener?

 

[littleredrider 408]

Think it just absorbs the sounds...

[peter lena 8,050]

if you can get some stainless steel lathe trimmings, that will do it , they really stand up to heat , pete

[gwest_ca-(File Mod) 10,491]

I can't see fiberglass standing up to the heat.

If you had room a rock wool insulation will take the heat.

 

Garry

[WHX?? 46,729]

36 minutes ago, gwest_ca said:

can't see fiberglass standing up to the heat.

It will Garry, scrap piece got thrown in the shop stove and laid in very hot coals for hours didn't touch it. Rock wool is ceramic and will never burn, that's what is in side of class A chimney pipe. It might muffle noise better. 

[Achto 26,545]

1 hour ago, ebinmaine said:

Does the exhaust go THROUGH the fiberglass or did you use that only as a sound deadener?

 

Correct it is just used as a sound deadener.

[WVHillbilly520H 10,369]

One might say I have an upper hand on the the "exhausting" situation we have here as I worked for 22 years at Tenneco Walker Exhaust Systems in their only aftermarket facility in the USA,  Yes fiberglass is used as a sound deadening/absorbent yes the variant they used was heat resistant but NOT heat or flame proof , it did come in as bulk "pads" or strings that they calling "roving" used in "glasspack" mufflers and also their Super Turbo and Dynomax performance mufflers as well as their top tier O.E. style factory replacements line called QuietFlo... Here is some more insights... https://www.revzilla.com/motorcycle/bassani-exhaust-fiberglass-muffler-repack-kit ... @ebinmaine please don't "exhaust" yourself over this

.

[ebinmaine 63,081]

@WVHillbilly520H

Jeff I was hoping you would "pipe up"  and "sound off"  here.

 

 

After I posted this I was poking around on a Forest Service listing.

Never even occurred to me but it does make perfect sense that there are recommendations and approvals on certain products to prevent sparks from coming out.

 

I don't have a link to the product but I did see a fiberglass mat that is USFS approved.

 

 

Question... Is a straight through muffler normally considered to be more noisy than one which directs the gases through a set or two of baffles/holes?

 

 

[Achto 26,545]

1 hour ago, ebinmaine said:

Question... Is a straight through muffler normally considered to be more noisy than one which directs the gases through a set or two of baffles/holes?

 

Strait through is going to be more noisy. Also a small diameter pipe tends to have a higher pitch than a larger diameter pipe.

Edited May 11, 2020 by Achto

[WVHillbilly520H 10,369]

1 hour ago, ebinmaine said:

 

Question... Is a straight through muffler normally considered to be more noisy than one which directs the gases through a set or two of baffles/holes?

 

Short answer Yes, but with fiberglass packing or mat wrapped around the the louver or perforated tube the sound is (as with their Dynomax mufflers) considerably less than non-packed varieties or other brands.

[ebinmaine 63,081]

3 minutes ago, Achto said:

 

Strait through is going to be more noisy. Also a small diameter pipe tends to have a higher pitch than a larger diameter pipe.

 

1 minute ago, WVHillbilly520H said:

Short answer Yes, but with fiberglass packing or mat wrapped around the the louver or perforated tube the sound is (as with their Dynomax mufflers) considerably less than non-packed varieties or other brands.

 

 

 

 

Very nice. Thank you.

 

I'll take a picture of a drawing I made up and a couple of pipes I'm thinking of using later on today.

 

I'd like to have this "relatively"  quiet.

 

[CCW 1,201]

@WVHillbilly520H Can you over pack a muffler?  Can a muffler affect performance of the engine?  I have always wondered about the second question.

[ebinmaine 63,081]

1 hour ago, CCW said:

muffler affect performance of the engine

In bigger engines.... DEFINITELY.

 

To some smaller extent even a little single would be "choked" by the wrong muffler.

[WVHillbilly520H 10,369]

1 hour ago, CCW said:

@WVHillbilly520H Can you over pack a muffler?  Can a muffler affect performance of the engine?  I have always wondered about the second question.

Yes in effect you can over stuff/pack a muffler as we had flow meters and scales to control the amount of packing/roving blown into each assembly by engineering specs... 2cd answer Yes the overall design (flow route/number of internal partitions) of a muffler the size and type of internal tube(s) whether double or single louvered or just perforated/punch and the pattern of both and open or packed all affects not only sound but how it helps (free flowing/scavenging) or hinders (back pressure)... Think large O.E. mufflers to meet federal noise pollution requirements but then small aftermarket "performance" mufflers not quite quiet but mpg and seat of pants dyno improvements... Ok back down off the soap box for now.

[WVHillbilly520H 10,369]

3 hours ago, ebinmaine said:

 

Very nice. Thank you.

 

I'll take a picture of a drawing I made up and a couple of pipes I'm thinking of using later on today.

 

I'd like to have this "relatively"  quiet.

 

Just remember the sound of an engine is just the remnants of fuel mixture spark "explosion" that are exhaust pulses... Some sound better (ex SB/BB V8 cammed up through headers) vs most any 4cyl through a "fart can" Fast&Furious muffler J.M.Humble.O.

[littleredrider 408]

I bought one of those fart can mufflers for my 4 wheeler to try out. It was LOUD. But what's funny, is about every ATV muffler is the same, basically a glass pack, just looks different from the outside, but some charge an insane for a stupid muffler. The fart can is a straight thru design, inlet is 2 1/4" but think it opens up inside the muffler. I have Borla's on my truck, and they are straight thru, but are quiet. I've always wanted to build a muffler, maybe I can be rich like Flowmaster lol. 

[bc.gold 3,399]

People often confuse rock wool with ceramic wool, these are two different animals.

 

ROCKWOOL products have a high melting point of 2150°F and can operate at high temperatures.

 

Ceramic wool has a working temperature up to 2300°F and a 3200°F melting point

 

 

 

[tom2p 2,393]

5 hours ago, CCW said:

@WVHillbilly520H Can you over pack a muffler?  Can a muffler affect performance of the engine?  I have always wondered about the second question.

on a two stroke engine - especially a small two stroke - the muffler can make or break the performance 

 

not only can affect the total horsepower - but the amount of power produced throughout the operating range (various rpm's)

even something as minor as repacking (replacing) worn / oil-soaked packing on a straight through muffler makes a difference 

 

[ebinmaine 63,081]

11 hours ago, WVHillbilly520H said:

... Some sound better (ex SB/BB V8 cammed up through headers) vs most any 4cyl through a "fart can" Fast&Furious muffler J.M.Humble.O.

 

Agreed.

 

It's rare I hear a 4 anything on the street that sounds reasonable to me...

 

 

[ebinmaine 63,081]

11 hours ago, WVHillbilly520H said:

muffler

 

 

Here's a descriptive drawing of what I'm thinking.

 

Keep the small pipe one solid piece for structure.

Drill a few dozen holes.

 

I'd use rivets instead of welding only because I don't want to discolor the chrome.

 

 

Here's the pipe section I would cut in half to make 2 mufflers.