Muffler fabrication and materials

[sen2two]

I'm going to be making my own aluminum muffler to shave a few pounds. It will have a 5 inch aluminum body about 18 inches long. An entrance and exit of 3 inches. Also a three inch perforated stainless steel center tube and hopefully, if I can find them, stainless steel mesh cones. Its basically a rip off of a flowmaster Hushpower muffler. But in aluminum. Google will show a cut out of this.

https://www.google.com/?gws_rd=ssl#safe ... er+muffler


After some research, it seems the best packing I can find is called Superwool.

http://www.morganthermalceramics.com/pr ... re/blanket


This is where I found I can purchase it. But I'm unsure if its the same product since there's not much information. Has anybody used this before, and know of a reliable source?

http://www.axner.com/superwoolfiber-1th ... rsqft.aspx


Also, a preffered place to buy stainless perforated mesh tube and cones. I found a few. But just in case the knowledgeable people on here have found a better source, post it up!

[bob]

My last attempt at a DIY muffler was a disaster. They were stainless oval boxes and they "panned" at tickover . they cracked up over a period of time and if I revved the engine in anger the air filled with the stuffing as if someone had shot a duvet with a 12 bore shotgun . The writing you see pressed into the cases of the aftermarket units is not there for show, its actually strengthening them, I gave up and bought some after this.

Bob

[seven13bt]

We used stainless steel wool from McMaster.com for our race mufflers. It came in 5 lb reels.

Also had to occasionally replace the perforated core. Used SS perforated sheet (0.060" 304) from Mcmaster to fab 4" OD tube.

The case was 8" round SS 304 and lasted more than 10 years.

[horizenjob]

Here's a few pointers. I have some more somewhere...

http://www.coneeng.com/index.html

http://www.headersbyed.com/hc_ventext.htm

http://www.exhausting101.com

[Lonnie-S]

Here are a couple of other things to look at:

http://www.acsindustries.com/products/a ... fault.html

http://www.fibretech.com/microtex.html

http://www.piteraq.dk/flight/muffler.html

Baffles, tubes, inserts, etc. ==> http://www.carchemistry.com/

Cheers,

[gavin_eakins]

Hi sen2two,

I've had great results with Acousta-fil. Not quieter, just doesn't blow out.
I used to use scrap fibreglass insulation (my Dad had a fibreglass factory). It would eventually blow out, even with (say) woven glass wrapped around the perf tube.

Acousta-fil is put in loose & it expands with heat.

Cheers - Gavin.

[sen2two]

The prefforated stainless sheet metal from McMaster is more expensive than I thought. It comes in at about $50 for a piece big enough to make one muffler. I'm Making It 18" long with a diameter of 3" where the exhaust will pass through.

I might just go with a pre-made prefforated tube made for mufflers. I found these for around $40. Unless I can find a cheaper sheet metal option that dosnt involve me drilling a couple hundred holes.

[Bent Wrench]

I would not use any metal packing. I'd be real concerned about it migrating into the cylinders.

Having witnessed how pieces migrate in motor explosions,
combined with how reversion can make fuel standoff above a carb.
I would never use such a product on one of my motors...