During paint prep, I discovered that my OEM muffler has a gaping hole in the side. I have to do something since the blast is scorching/sooting the new paint on the access panel.
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TinyPic insists on rotating this photo 90 degrees left.
I'm not even going to contact Gillig about their price. I suspect the OEM is overly restrictive, anyway. LuckyChow suggests what I think would be a workable patch, but a little research leads me to believe that a Donaldson muffler might be a reasonably priced option. Some volume increase would not be a problem, but DW often sleeps in while I'm driving. Rear bulkhead is well insulated, but that pipe is in her vicinity.
40 Series Detroit. I measure the muffler inlet at 4-1/2". I have about 48" of space before the current pipe goes through the roof panel, but nothing's stopping me from opening the hole if need be for a longer muffler.
Any thoughts?
TIA
United Mufflers or any school bus parts I think that is a Walker or Nelson muffler
Check that inlet tube size again. 4.5" is found most often on Caterpillar off road equipment. Not too many listings for on highway use with 4.5". Don't forget the inlet is (usually) I.D.
Here is a link to the Nelson catalogue pages. http://www.nelsonglobalproducts.com/catalogs/ (http://www.nelsonglobalproducts.com/catalogs/)
Thanks for the link, Jim. The inlet is 4-1/2".
Just bought a Donaldson truck muffler on ebay. 5" inlet and outlet. The inlet on my muffler measures 4-1/2", but I can't find anything that size in truck muffler catalogs. I will adapt to fit the new muffler. No big deal. The hardest part will be removing the old muffler.
My Gillig parts manual says that the OEM is a catalytic muffler. The new one will not be, but I can't imagine that being a problem. I would expect slightly better flow with the new, straight through muffler.
Jim
Really? 4.5" imlet muffler would probably be more expensive than the run of the mill 5" inlet. Quite a number of customers pitched their catalytic mufflers when their truck was brand new. The local Ford dealer (when Ford was selling heavy trucks) would send us catalytic mufflers for us to open them up and cut out the element. Apparently on Ford of Canada's instructions but that would be a closely guarded secret .... ooops.
BTW the Nelson number for your needed adapter is 900096A (5" OD - 4.5" ID). Between 20 - 30 $
Thanks again, Jim. I really appreciate your help.
Jim
If the engine has the waste gate turbo as most of the 466 engines have it will need the back pressure for the waste gate to work,but you can use what ever muffler you choose
Thanks, Clifford. I'll put up some photos as I change it.
Jim
Go on Donaldson muffler site. They have numerous mufflers from 2.5" up to 6". Should be less than $200. Good Luck, TomC
Quote from: Lostranger on April 26, 2015, 11:10:26 AM... My Gillig parts manual says that the OEM is a catalytic muffler. The new one will not be, but I can't imagine that being a problem. I would expect slightly better flow with the new, straight through muffler.
Jim
The 8.3 Cummins in my '03 Gillig (the donor bus) had a big catalytic muffler, too. I've run it in the shop a few times and even if it's run for 10 minutes or so, you can't see a wisp of smoke or soot and there's no smell of exhaust. I was pretty impressed. However, I'm pretty sure that there's no room in my new installation for a muffler that big so I'll probably need to change out for a "normal" muffler, too.
Thanks for letting us know your experiences, it's helpful.
What are you guys going to do about the code when the ECM finds out the catalytic converter is missing and not functioning,dealers won't help you BTDT
Quote from: luvrbus on April 28, 2015, 06:47:37 AM
What are you guys going to do about the code when the ECM finds out the catalytic converter is missing and not functioning,dealers won't help you BTDT
Does the ISC have a post-cat O2 sensor? I'm pretty sure the early ISBs did not, in which case the ECM does not monitor catalytic efficiency.
Clifford, how do you manage to always look on the bright side?
Inquiring minds and all.
Jim
LOL I just try too keep you guys out of trouble which is hard to do sometimes but I would call DD and let them run the serial number to see if the ECM is reading the catalytic converter on your series 40 or use a Pro/Link and check it yourself if you have one
At times like this being a good friend with Ken Arnold might be a good idea
uncle ned
New muffler arrived today. UPS damaged it, of course, but nothing I can't straighten:
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Tomorrow I'm gonna attempt to swap it into this space:
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And silly me, I finally paid enough attention to see that I had been measuring the lower end of an adapter clamp rather than the muffler inlet. In my defense, it's been dark and I was in a hurry both times I measured, but mea culpa. My new muffler has 5" inlet, and that MAY be perfect:
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More tomorrow night. Wish me luck.
Jim
P.S. I hate TinyPic. All of these images were rotated 90 degrees left, and I can find no way around it.
That's going to be a hard switch over. Why didn't you buy an oval muffler like what you have? That long muffler is going to be a PITA to try to get in. I would return that muffler (the damage is a good excuse) and look again for a more suitable one. Good Luck, TomC
Where is the outlet on your original muffler?
They usually don't make catalytic mufflers in an oval format but it is possible I guess. Navistar added in a catalytic section to their in use mufflers in the beginning (early 2K) to experiment with which were 8.3" x 11" but switched to round for the actual production models.
That OEM muffler is double wrapped (outer jacket is crimped onto the edge of the body) meaning it is quieter than your chosen one both noise transmission through the muffler body itself plus higher exhaust noise level out the pipe. Some like it that way though.
This is due to the fact the original runs through a series of baffles (not a direct flow with possible one baffle like your Donaldson vertical version).
Most any 10x15 oval muffler is going to run you close to $200.00 and if it is double wrapped add some more. In the long run it may be better to spend some extra now and enjoy a quieter drive later but like I said, some like it loud(er).
Finally, 8 days after starting, I have the muffler job finished. Wasn't working on it all that time, of course, but it was certainly on my mind while I attended to other stuff that jumped in my face.
Tom and Jim, thanks for posting. I certainly appreciate your help.
I've posted the full update on my build blog: http://nomadicista.org/viewtopic.php?f=4&t=2541&p=20880#p20880 (http://nomadicista.org/viewtopic.php?f=4&t=2541&p=20880#p20880)
Here are the highlights. I started with this:
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And ended with this:
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Once again, TinyPic is rotating my photos 90 degrees left. Sorry. Nothing I can do.
I love the new muffler. Maybe a bit louder — only time I notice is when I'm driving beside a building — but it fits the space better, and the acceleration is dramatically improved. Can't wait to check MPG.
New upper mount came out well:
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With the hatches closed, no one would know it isn't stock.
I saved at least 70 pounds in this swap. I spent $120 on parts/shipping, and best of all, any future muffler swap will be quick, easy and inexpensive.
Glad the old one blew. It was an excellent excuse for an upgrade.
Jim
Quote from: Lostranger on May 07, 2015, 07:39:38 PM... Glad the old one blew. It was an excellent excuse for an upgrade.
Jim
Good looking work, Jim. I hope to be there in a few weeks and I'm bookmarking your photos.
Great job Jim looks clean, mea maxima culpa, lol ::)
Dave5Cs
Nice work. If heat gets to be an issue you can install a diffuser upstream of the muffler, given sufficient straight tubing section.
Jim, where are you thinking heat might be a problem?
Just based on the fact the OEM was double wrapped. Not only does it reduce noise it reduces the heat of the surrounding area. If that was one of the original design criteria then some concideration may need to be given to the heat issue.
Bluebird owners have had a few fire problems replacing the double wall muffler with a single wall, I am happy you told Jim I stayed out of it ::) as i know the series 40 (DT466) can reach EGT in excess of 1100 degrees under a load
I could easily wrap this muffler with header wrap. Would that be a good idea? What is a diffuser?
Jim
Blanket insulation is the best if Mike (Lowtide) didn't take it all I may have enough left I can send you for shipping to wrap your system I'll check and see
Thanks, Clifford.
I realize that what I'm about to report is in no way scientific or definitive, but I find it interesting. Had the bus on the interstate today for the first time since the muffler swap. Ten miles at 65 mph. Engine up to temp the entire way.
When I arrived at the tire shop, I immediately went back to the access panel beside the muffler. It's the closest thing to the muffler in any direction. Used palm of my hand to feel this panel from top to bottom. It was barely warm to touch. The original muffler got this panel much warmer to touch, but only on the lower half.
When I got back home, I did the same test again and also opened the rear hatch so I could feel the inside of the access panel between the muffler and the side. Same story. Barely warm to touch.
I need an IF temp gun anyway, and I'll try to get one soon, but so far, I see no indication that excess heat from the new muffler will be a problem.
Jim
P.S. The coolant temp seemed to run a few degrees lower than it did with the old muffler, but I can't be sure without further observation. Ambient was about 90 degrees F.
Anyone still looking I have a Nelson muffler 5" in and out. But shipping would be $$$. If the muffler you removed is a Catalytic it may have some value, the cats from some cars have a good junk value.
Good to hear. The old system could cause the panels to warm up more because of proximity to the panel (size) or because it is an offset design (looks like from here) which creates more heat requiring the "double wrap" in the first place but having limited success. If the straight(er) through design of the Donaldson vertical muffler runs cooler then no worries. Enjoy the fuel/power benefits and the hot rod sound. ;)
Nice KISS installation.
Can't find a picture of a diffuser but have a look at the "twin" tip of a late model Ford 3/4T Super Duty there are small "flaps" bent in to create a venturi to draw in atmospheric air to mix with the exhaust gases. This does two things, reduces the exhaust outlet temp significantly and dilutes the exhaust much the way the 70s-80s cars used an air pump to meet then current emission standards.