How to baffle a 2" dia. ss exhaust tube......screw mufflers!!!!!!!! 1. 2" dia. ss fender washer....see pic#1 2. Cut it in half....see pic#2 3....drill three holes...3/8" to 1/2" dia....see pic#2A 4....cut a slot 1/2 way through the 2" dia exhaust pipe see pic#3 5....insert the washer, and weld it in solid 6....move down the pipe approx. 3" and cut another slot, but cut it 180 degrees to the first cut 7....as the hot gasses go down the tube they are still expanding, so for your third cut move down 4" and make another cut, then 6'' then 9" ect.(stagger the cuts either 90 or 180 degrees) 8....I did seven (half washers) for my 181 c.i. Chevy II powered Model "A" rdstr p.u., and I've been running it like this for several years.....no tickets, but it is a little loud. I might add a few more washers some day, but it isn't high on my list of things to do. 9.... the ss washers are thin, so they fit in the saw cuts better than a Fat mild steel washer............. 10....Have fun experimenting with this, and let us (H.A.M.B.) know if you come up with a better combination
The 2" dia. washers are actually fender washers.............the hole in the fender washer is 1/2" dia.
It actually works very well. It is real easy to do, and the sound isn't "that" loud with only 7 half washers........ my wife thinks it sounds good, and says I shouldn't quiet it down. My 181 c.u. banger has a single exhaust pipe, with the 7 baffles..........that is the equivalent to a 362 c.i. dual exhaust v8, with 7 baffles in each tail pipe! Maybe a math wizz can calculate the exhaust restriction. With a 2" id pipe, it cuts down to a 1" opening, plus the openings for the 3- 1/2" holes, and half of the 1/2" center hole. What would the unrestricted opening be? The bottom line is that it works well, and would be real helpful on any hot rod where there isn't enough room underneath for any mufflers. Also I don't know if I made it clear, if you cut the slot exactly halfway through the pipe, you can just slide the 1/2 washer into the slot and the edge of the washer will fill the slot and make it easy to weld the slot shut. You don't even have to clamp it! Easy to do, and easy to add more if needed.
I haven't got a decent calculator handy, but if I did the math right you've gone from roughly 3.14 square inch to 2.26 square inch open area. So basically you've gone from a 2" diameter opening to a 1.75" dia opening. I'm not sure what you mean by step 7? If this is to minimize restriction, you've got it backwards. The washers will have a bigger effect in the hot area of the flow than in the cooler area. It's best to put them as far down the pipe as you can from a restriction standpoint, but they may not quiet things down quite as much if you do that. And the restriction probably isn't an issue anyway...
As the gasses are still expanding as they go down the pipe, you space the washers farther and farther apart, thus creating bigger and bigger chambers, which helps reduce back pressure. I came up with the washer idea, and my friend Wes, who is an engineer, explained the expanding gasses part of it.
Hmm... Waukesha... an engineer... If I had to guess, I'd say Wes does engine calibration work for Harley? ;-) Anywhos... the thing is, exhaust gas is more viscous the hotter it gets, opposite of what you'd think, so it's best to have as few restrictions as possible in the hotter part of the flow. It cools as it expands so becomes less viscous and less affected by the washers...
Actually I was saying that the Wes I know, who I think lives in Waukesha, is an engine calibration engineer with Harley... sure it was a longshot, but hey, you gots ta take chances sometimes .
Has anyone else tried this ? I'm just wondering how the sound is on your car. What engine are you running? Where did you place the washers, near the engine or near the back or somewhere in the middle. How many half washers did you end up using? You don't have to use stainless pipe, but it works out better to use the stainless fender washers because they are thinner than mild steel washers and fit in the hack saw kerfs better.
What kiind of sound do you get from something like this ? Glasspacky? Turbo mufflery? how would you describe it?
At partial throttle the Chevy 2 motor sounds like a loud model A, it has that same kind of sound. If you hit it and then back off it raps like a Chevy 6, but not as extreme. It's loud but not real loud or obnoxious. I sure would like to hear what other cars sound like. As cheap as this is to do, I would think someone else has tried this. Also if anyone is running straight pipes and think they are slightly too loud, adding a few washers would be easier than putting mufflers on. You could gradually add washers until you satisfied with the tone.
Sounds like a great idea. I'm currently building a Chevy II four banger. I was just thinkin about what kind of exhaust I'm gonna run today. And I just hapen to have a bunch of 2" stainless. Hows about some pics of the truck. Later Count
Count, here is a pic of my 29 "A" I scanned off an old photo. My buddy Wes, his brother Bill and I built this in the mid 80's. Antique Auto Sheet Metal (Brookville Roadsters) body, Rootlieb hood, TCI TCI frame, Pete & Jakes suspension, Chevy II (181ci) and turbo350 trans, and a 8" rear end.
...I like that roadster pickup and the fact it's runnin a four,...on usng stainless pipes; has anyone heard that stainless tubing is actually quieter by nature than standard steel tubing? I have a friend with a Chev V8 in a 47 Fleetline with dual stainless strate pipes that aren't that loud under normal driving conditions; but can be a little loud if you get on it. Any other experiences with this? ...I was just wondering if this washer idea would work using standard steel tubing, mite have to try that sometime.
Here is a pic of my 29 A rdstr pu with the Chevy 2 engine. You can barely see the exhaust pipe in front of the rear wheel in this pic.
Ive made street zoomies...used freeze plugs that had been drilled and drove them into the zoomie pipe. more/bigger holes = more noise/less restriction. Have fun !
I have a Stainless 4 into 1 header and straight pipe on my hi compression Model A engine. Sounds the same as stock so how do you make an A loud?
The general rule of thumb for pipe work is double you're diameter and quadruple your flow. Whats wrong with a rolled up bit of chicken wire stuffed down the pipe?
I have made several "mufflers" using similar techniques - some on larger diameter stainless, like this streetable champ car effort, with a removable baffle for on-track use.
I drilled them in a tube, since I had a 2" piece handy. The total area of all the holes adds up to around one square inch. I can drill more if needed, or enlarge the existing ones. With all that tailpipe volume upstream of it one square inch seemed like a good place to start. Even if I had rolled it I would have waited until the piece was rolled and welded before drilling so I could get a consistent roll up.
I built similar baffles for the Lakes style headers for the 215 Olds in my T roadster. I wanted a bit more silencing so I wrapped the center tube with stainless steel, steel wool and held it in place using thin stainless steel safety wire. Lynn
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