Muffler questions

Engine troubles? Try here.
andy
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Location: Comstock, TX

Post by andy »

Well, the muffler issue is at least temporarily resolved. Took the 712 in for it's yearly inspection and my buddy George had to fail it, because of the leaks in the exhaust system. I ended up going to the muffler guy anyway to weld the junctions/connections between the exhaust from the manifold and the heat exchanger and from the heat exchanger into the muffler.

Inspected, re-licensed, and back on the road. Also, found out the 712 hasn't had insurance since last March. For some reason it wasn't on the same payment schedule as the rest of the fleet and the payment fell through the cracks and I got cancelled. Now that is fixed and the '12 is on the same schedule as everything else.

I'm sure that ya'll's good advice will be needed anyway before too much longer, but I've got a little breathing room.

Thanks again.

Andy
A bar F
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blackstack
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muffler sourse

Post by blackstack »

[quote=" I will try to get the muffler first and see what the muffler guy has to say. Then if he is going to need parts, I can pay extra to Scott for expedited shipping.
.[/quote]

When you find an appropriate muffler would you mind posting the source and the model number?

thanks
pinztrek
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Re: muffler sourse

Post by pinztrek »

blackstack wrote:When you find an appropriate muffler would you mind posting the source and the model number?
OK, someone write this down as it was a real pain to find again! :) Once I found it, a quick google shows it's documented on Jeurgen's site:

http://www.sdp-pinzgauer.org/html/muffl ... ement.html

Muffler model is an IMCO CM35. It's off of a Mercedes Sedan of some type, and IMCO was the only company I found still with that model, so I think it's kind of old. It's still available as of 2-3 months ago I know, but now listed as a "universal fit".

At the time I ended up flipping through hundreds of pages of muffler mfg catalogs at a wholesaler before I found it.

It's not cross referenced by any model, just says "mercedes sedans", which is of no use to the counterman who only knows how to use the computer. It also does not pull up most of the time as CM-35.

Scott deserves credit for the find, as he had posted this almost a decade ago in the original mailing list and I just happened to run across it in my archives. (I have all the old mailing list posts from start through several years stashed away)

I still have the catalogs. For those of you outside of N America, no idea if this muffler has a local match. But in UK/Europe I'd have to think there are still old mercedes sedans who use it

Here are the dimensions in inches:

Code: Select all

Body Size Width	6
Inlet Size	1.875
Outlet Size	2
Overall Length	20
Reversible ?	N
Shell Size	16.5
Again, buy a complete setup if you can from Scott, Dennis, etc if at all possible. You'll save yourself some hassle. I would have bought Scott's setup if he had offered it at the time.

To Dennis's point, you do need to cross brace the muffler. I found one of the original cross braces works fine with a new hole drilled in it.

Have fun,

Alan
Erik712m
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Joined: Sun Jan 21, 2007 7:52 pm
Location: Wichita, Kansas

Re: muffler sourse

Post by Erik712m »

pinztrek wrote:
blackstack wrote:When you find an appropriate muffler would you mind posting the source and the model number?
OK, someone write this down as it was a real pain to find again! :) Once I found it, a quick google shows it's documented on Jeurgen's site:

http://www.sdp-pinzgauer.org/html/muffl ... ement.html

Muffler model is an IMCO CM35. It's off of a Mercedes Sedan of some type, and IMCO was the only company I found still with that model, so I think it's kind of old. It's still available as of 2-3 months ago I know, but now listed as a "universal fit".

At the time I ended up flipping through hundreds of pages of muffler mfg catalogs at a wholesaler before I found it.

It's not cross referenced by any model, just says "mercedes sedans", which is of no use to the counterman who only knows how to use the computer. It also does not pull up most of the time as CM-35.

Scott deserves credit for the find, as he had posted this almost a decade ago in the original mailing list and I just happened to run across it in my archives. (I have all the old mailing list posts from start through several years stashed away)

I still have the catalogs. For those of you outside of N America, no idea if this muffler has a local match. But in UK/Europe I'd have to think there are still old mercedes sedans who use it

Here are the dimensions in inches:

Code: Select all

Body Size Width	6
Inlet Size	1.875
Outlet Size	2
Overall Length	20
Reversible ?	N
Shell Size	16.5
Again, buy a complete setup if you can from Scott, Dennis, etc if at all possible. You'll save yourself some hassle. I would have bought Scott's setup if he had offered it at the time.

To Dennis's point, you do need to cross brace the muffler. I found one of the original cross braces works fine with a new hole drilled in it.

Have fun,

Alan

Now that it's on the forum. It will be easy to find. :D I didn't realize how long scott has offered the MB muffler. Great find.
pinztrek
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Re: muffler sourse

Post by pinztrek »

Erik712m wrote: Now that it's on the forum. It will be easy to find. :D I didn't realize how long scott has offered the MB muffler. Great find.
Well, actually only until the next crash or hack. The forum has lost messages more than once. No slight to Vince, it's the nature of the BB beast, and has hit many, many forums.

Lot's of stuff people are asking about periodically were originally posted here, but have been lost. Jurgen saved some of it along the way. I had to go way back in the yahoo archives I have offline to find scott's original post on the muffler and even then could not find a way to order it. Finally found an IMCO wholesaler, looked through catalogs.

I'd love to see RSS turned on for this forum. I'd be happy to help set it up if needed. It would allow folks (like me) who want their messages to come to them to read just like email. Also an easy way to archive off messages to prevent loss during crashes.

Have fun,

Alan
andy
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Location: Comstock, TX

Post by andy »

Alan, thank you for your sleuthing time and abilities. I will be thinking greatfully of you in a couple of weeks when I go back to the muffler guy and ask him to get one of those mufflers and make me a longer exhaust pipe for the 712.

Luckily the 710 made it through it's inspection today without any hitches and it's good for another year.

Really do appreciate what you've done here and I hope it doesn't get lost again.

Andy
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pinzinator
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Post by pinzinator »

Has anyone ever added a converter when installing a new muffler? I wonder how that would work, assuming there is room to install one.
M Wehrman
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Post by M Wehrman »

***** Has anyone ever added a converter when installing a new muffler? ****

Unless you are running EFI,preferably a full feedback system , a converter would be a short lived thing. The carbed Pinz runs much too dirty to allow the cat to work. It would plug up,and besides you stand a chance of setting fire to the great outdoors! :lol:
Mark
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68 Haffy
pinztrek
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Exhaust -> Cat -> EFI

Post by pinztrek »

Mark's right.

Even with EFI there are operating ranges (both low & high) where we choose to make the mixture richer than a cat would like.

You could probably make a pinz run on a perfectly "stoich" system, but it won't run as well or as smooth. And depending on circumstances and opinion, you may be missing some cooling from the normally rich mixture.

There are lot's other circumstances when we chose to have the mixture run right at stoich (which is the "perfect" air/fuel ratio for complete combustion, 14.7).

You really don't want to run lean, and likewise running too rich does not work as well either. There is a range that the pinz engine is happy, and it's wider than I would have thought.

If you have to meet emissions EFI would be a very good start. I'm pretty confident I could make one pass seventies emissions with our current tuning.

But to move to modern emissions you have to start changing your engine design. The long stroke 6 cyl engines like the famous slant six did not die because they were bad engines, it's the fact that it's much harder to meet emissions on long stroke engines. So now you see square or shorter stroke engines. Same for valve size/timing, injector locations, etc.

There's also a reason you don't see many classic air-cooled car engines in modern production... they typically like richer mixtures, and that just won't work for emissions.

While we are talking air/fuel mixture, here's a question for us gearheads to ponder: For a given HP output there is a required fuel mixture. Make more HP and fuel usage goes up, all other things equal. And for that fuel mixture, a required air volume. It's basic chemistry, stoichometric.

when we go from carbs to EFI *in the pinz*, we're not changing volumetric efficiency for the most part- the amount of air & fuel the engine can process. That typically requires valve/cam changes.

So the amount of fuel to produce a specific HP pretty much stays the same even with EFI (in the pinz world).

So how do you increase gas mileage? certainly the carbs ran way rich. But were they 25% rich? You can artificially improve mileage by running lean, but with lot's of undesirable side effects. (engine life being the main one).

But it's very difficult (technically impossible) to make more HP and have fuel usage go down unless you are really changing the internal efficiency of the engine. Or going lean, one.

I think one answer might be that if you make more torque lower, you don't get into the higher HP (and fuel usage) ranges. But that's just a theory. Hit the go pedal less.

Not much to do with mufflers, but since we went down the EFI path, just something to ponder. Mufflers do factor in one aspect: oversized exhaust decreases backpressure overscavenging the engine, and sometimes reduces torque. I don't think we are there with the pinz. But neither was the muffler a constraint.

Any thoughts?

Have fun,

Alan
norcal pinz
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Post by norcal pinz »

This looks exactly like the muffler set up on my K, it was on there wen i got it.
710M 1972
710k 1974
todds112
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Post by todds112 »

I got one from Scott at EI. It has a Mercedes emblem on it. unfortunately the last I heard he wasn't offering them anymore. Too bad, it matched right up. Improved ground clearance too.
1973 712M
ExpeditionImports
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Post by ExpeditionImports »

Hi Guys,

A little update on these. Last year we had discontinued the exhaust systems as we are not completely sure it is a "do it yourself" option. Quality control issues, as well as everyone wanting their own slight modification made it a nightmare to manage.

The waterjet flanges are sitting here, so I will run another batch of the Mufflers. Piping will be up to the individual customers and or their exhaust shops.

In addition, if you want to go it alone with the Imco muffler and don't want to cut and re-use your flange, I do have the flanges available.

I have seen NUMEROUS successful muffler jobs done on the Pinzgauer. A quality shop that knows what they are doing should not have any problem setting someone up.

Last but not least, the Imco muffler is NOT extremely robust. So if your truck is runnng like crap and likes big backfires... save yourself the money and get your problems fixed prior to installing the muffler. Most warranties will be against rust out/defects. A muffler blown apart from the inside does not usually fall under warranty.

Cheers,

Scott
Expedition Imports Corporation
Vallejo, California
www.expedition-imports.com
"You didn't buy a Chevy..." "Hows that Amazon tech support working out...."
blackstack
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IMCO Muffler

Post by blackstack »

Hey Scott!!

Which IMCO muffler are you talking about? The CM35? All of the shops I talked to said they could not get it as it was discontinued.

I called IMCO and they confirmed that and said they didn't manufacture one with a similar configuration (2 in 1 out)

Looking forward to your new muffler offering

Bob Gray
ExpeditionImports
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Post by ExpeditionImports »

Hi Bob,

Jury is still out on this. The conversation went somewhere along the lines that the mufflers are on SFO (special factory order) and they would run a batch if I bite off a substantial number. We will see what the end result is.

Cheers,

Scott
Expedition Imports Corporation
Vallejo, California
www.expedition-imports.com
"You didn't buy a Chevy..." "Hows that Amazon tech support working out...."
lindenengineering
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Post by lindenengineering »

pinztrek and others
Here's a link to get absorbing before bedtime!
http://franzh.home.texas.net/lean.html

Some manufactures are getting there, even Honda did make some significant strides with its stratified engine in the seventies.
This makes good reading
Dennis
OOOps no customer bashing now
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