| Author |
Message |
Jim Shepherd (Rv_safetyman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 17, 2005 - 3:20 pm: | |
Down the board a bit is a thread on a stainless steel muffler problem. It was custom built. Since the thread is getting a bit old and because this is a bit of a twist on the subject, I am starting a new thread.
It just so happens that today I am trying to fit a muffler into my Series 60 conversion in my Eagle. Turns out it is a huge task using existing mufflers. My Series 60 is a 475 HP setup and I think I need some pretty good flow (at least 3000 CFM at 2100 RPM). The outlet of the turbo is for a 5 inch pipe. I can find a short 5 inch inlet/outlet muffler that might fit, but it has a max flow of 2478. All of the high flow mufflers are long suckers and won’t fit. I know it does not make any sense that a longer muffler would flow more, but that is what the Donaldson specs say.
I would like to go with a 6 inch muffler (short) for the flow and still get a bit of muffling, but the shortest I can find is over 32 inches and won’t fit.
I have been the no muffler route before on a truck I made into a motorhome. It was just too loud and I want to be a “better neighbor” this time.
Soooo, I want to build my own muffler. Are their components available somewhere? If not, how does one go about making the parts? The shell and ends are no problem, but I can’t figure out what to do about the inside tube.
In lieu of building my own, is there a better source for a 6 inch muffler? Has anyone cut down a muffler to shorten it?
Jim Shepherd
Evergreen CO
’85 Eagle 10 |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 17, 2005 - 3:40 pm: | |
JIm,
First off, I didn't rerun your figures but if the 3000 CFM figure was derived from "displacment x RPM", I'd submit that the cylinder pressures and temps are considerably above ambient and will expand and your requirements are above 3000 CFM.
Mufflers attenuate sound by reflecting it about corners. The temps involved don't allow the interior sound-deadening like the genset sound boxes, they rely on frequencies, wavelengths and specified dimensions. Cuttin down a muffler may cause problems.
How bout splitting the downpipe and running thru 2 mufflers that are short enough? The other possibility would be extend the bumper slightly and go transverse across the back with the muffler????
Finally, I recall from physics class that a pulse thru a tube of a set diameter and length would express at a certain wavelength. I often wondered if a collection of tubes in parallel would break the exhaust pulse into "white noise" but I never tested the idea, quickly guessing that it was so obvious it would have been done if any merit to the idea.
Onward and Upward |
Gary Stadler (Boogiethecat)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 17, 2005 - 4:06 pm: | |
Why not just talk to a muffler pro? There's a lot more to muffler science and design than stuffing some metal downspout pipe into a can.
I've had extremely good relations with these guys, and they do a lot of big rig & bus stuff...
http://www.auto-jet.com/ talk to terry |
Don Fairchild
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 17, 2005 - 6:37 pm: | |
Jim, The book shows the 6V92T 322hp 2100rpm flows 2911cfm exhaust. the 12.7ltr 60 series 470hp 2100rpm flows 2877cfm exhaust. Try part # M140048. It is 6" in and out 30"s long. There are 4- 5" in the 26 and 28" long catagory.
Hope this helps
Don |
Jim Shepherd (Rv_safetyman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 17, 2005 - 9:47 pm: | |
OK folks, it did not take long to talk myself out of making a muffler. Listed below are a couple of replies to some of the posts and a question on a “muffler insert” that I hope some of you good folks might have some input on.
Marc, I got the flow from the DD site for generators. They were 14L engines, but I factored for that for my 12.7L. Per Don, I must have been pretty close. No room for a transverse due to the hitch.
Gary I went to Auto-Jet and it is a great site. I downloaded their catalog. They do not have a standard 6 inch muffler, but it sounds like they would make one.
Don, thanks for verifying the flow. That almost dictates a 6 inch inlet/outlet muffler. The Donaldson you mentioned is really large (12X18) cross section.
I got an off-board reply that sent me to: www.iowa80.com I had lost their catalog. BTW, if you travel I80 in Iowa, it is a very fun place to stop and they have a great truck show in July. At this site, I ran across an “internal muffler” or muffler insert (see item 08301). This is a device you insert inside a 6 inch diameter pipe. It is intended for a truck exhaust stack, but I would use it in a horizontal application.
The insert is really interesting to me. My problem is that if I have a relatively large diameter (10 inches or greater) muffler, I don’t have any length to work with (get your minds out of the gutter <grin>). If I can stick with 6 inch diameter, I think I can get the 72 inch length I would need for the insert.
Does anyone have any experience with this kind of “muffler” for this size of application (they are used in motorcycles and some custom type car applications)? Does anyone know who the manufacturer is (did a google search and came out empty handed)?
Thanks again for all the help!! This is about the last major FABRICATION hurdle – still have all the electronic fun to deal with.
Jim |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 18, 2005 - 3:13 pm: | |
Jim - cut them in half and add flanges to the "new" ends - still quieter than straight pipes - Niles |
Bill Gerrie
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 19, 2005 - 6:41 am: | |
Jim
Take a look at the site www.aero-turbine.com for a small muffler. It now comes with a 5" in and out and is no more then about 24" long. We are now useing it on a 6V92TA and it is working good. A little noiser then we thought it would be but compact. Bill |
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