Stock exhaust '67 Chrysler??

[Scoopy G]

Hello gents, My '67 Newport Custom is running great, no issues, EXCEPT, I can't get the exhaust quiet enough.

I am sure that in '67, the exhaust on this car was very quiet. Now here in 2020, with all the blabbering noise going on constantly, I just want my Newport to be quiet. I had a shop put on a couple of mufflers to replace the rusted ones, but it still isn't quiet enough. SO...

What was the stock setup in '67? Mufflers and resonators? What was the pipe size coming off the manifolds? Mine is dual exhaust, but with just a 2-barrell. Is the pipe too big, does it need to be reduced? I'm no exhaust expert as you can see, but I don't want to hear anything but the engine purring at idle. Thanks for any help.

 

[bigmoparjeff]

You've got a few things working against you on this issue.

Your two barrel 383 Newport would have left the factory with single exhaust, which is quieter than a dual system. As it looks like you know, the larger the pipe diameter, the louder the exhaust will be. I think the stock pipe diameter would be 2-1/4" to the muffler and 2" out. I don't think it would have had a resonator as original equipment.

Modern mufflers are not as quiet as what would have come on the car originally or what would have been available as a replacement for many years after the car was built. Mufflers designed for cars with catalytic converters don't need to be as effective at reducing noise because the converter itself lowers the sound level quite a bit, and the internals of most modern mufflers are now of this design. As the numbers of non-catalyst cars dwindled, the exhaust manufacturers saved money by phasing out the old design, quieter mufflers.

Adding a crossover between the two pipes will usually reduce the sound level a bit. Adding resonators would also quiet things down, but you may not have enough clearance on the left side to do this.

Jeff

 

[Davea Lux]

You might also try advancing the timing as this will take the rap out of the exhaust noise.

Dave

 

[Scoopy G]

Thank you Jeff, wow, this is exhaust knowledge I did not know. So, it seems as though a previous owner just wanted to "hop up" the car with a dual exhaust, despite the 2-barrel.
I just want the car to sound quiet...I realize this isn't in vogue. Thanks for the help.

 

[Scoopy G]

Thanks Dave, I wonder if advancing the timing might give the car a bit more low-end pep?

 

[Davea Lux]

Thanks Dave, I wonder if advancing the timing might give the car a bit more low-end pep?

Yes it could, advance the timing until you start to get a ping and then back it off about 1-2 degrees.

Dave

 

[Scoopy G]

Ill try it Dave, thanks.

 

[CBODY67]

I upgraded my '67 Newport 383 4bbl, with the factory single exhaust, to the '72 Chrysler 2.5" inlet/outlet muffler and associated pipes, from the y-pipe back. No resonator. It's just right with a stock-replacment Walker muffler. The factory dual systems had two mufflers, same part number from Walker. Whether the normal size or the later larger size I used.

My recommendation would be to put the STOCK size muffler under it, not a generic muffler shop muffler, from my experiences. I believe Walker still sells one, possibly also available through NAPA stores, too.

The problem I see is that you already have a "muffler shop" exhaust, as the car originally came with a single exhaust. Personally, I've had much better luck (fit, durability, factory sound) using Walker Exhaust items, but that was when we could still buy most of the system new. I believe all they now service is the mufflers and some of the hangers. Waldron, or similar, would be sources for a factory-configuration kit, with the TTI system being a little more "will fit with work" situation.

You'll need to figure out the pipe sizes of the mufflers, inlet and outlet, and go from there. Unless you get a complete kit, as mentioned, with stock mufflers for the C-body Chryslers.

Takre care,
CBODY67

 

[pgrz]

Almost a year ago I had a local shop fab pipes to replace a very rusted and broken original single exhaust on my ‘67 Newport sedan (383, 2 bbl), and the original muffler was 24” long. Here’s some photos of the old system and what replaced it. The muffler was stamped with the Pentastar and number 17806, which I think is the same as a Walker number. The pipe ahead of the muffler looked to have had a small stretch of resonator built in. The replacement system has a similar muffler, no resonator in the pipe, and has a nice hum from outside but SO quiet inside. As a low-optioned near-original sedan, quiet seems appropriate.

 

[CBODY67]

Walker was an OEM supplier, back then, but only items coming through the assembly plants and Chrysler parts would have had the Pentastar imprint in the metal, I suspect.

Any resonators were usually behind the muffler, beside the fuel tank and frame rails. But they could be replaced by a "resonator eliminator" rear pipe, too. I suspect that most were.

There were a few other OEM-level exhaust system/muffler brands back then. Maremont and Arvin were a couple.

Thanks for the pictures,
CBODY67

 

[BigblueC]

I had a shop put on a couple of mufflers to replace the rusted ones, but it still isn't quiet enough. SO...

What mufflers have you tried and what did you not like about them? This Info could help us steer you to something you would like.

 

[cbarge]

I would add a couple cherry bombs in the tailpipes right before the tips.
They will act as resonators and will quiet down the system.
Most Chryslers with single exhaust 440 had a factory resonator/tailpipe assembly...just an example.
I would also trim back the tips a few inches. They should poke out no more than the top of rear bumper.
Hope this helps.

 

[jct]

Find Walker Exhaust SoundFX 17827

 

[Scoopy G]

Thanks as always fellas for your advice. I took the car to the muffler shop yesterday, and got the "old guy", Charlie on the case. He tells me that the mufflers the first shop put on were super el-cheapo, practically hollow with just one baffle. They were designed for maximum flow and maximum noise! Charlie created an H-pipe between the two downpipes, added much better mufflers, and brought the tips in a few inches. Everything was welded, great looking job. Now the car is nice and quiet, and looks better with the tips shortened. Cost me $500. I'm very happy with the result.
Now should I go back to the first shop and ask for my money back?

 

[Hubie]

Thanks as always fellas for your advice. I took the car to the muffler shop yesterday, and got the "old guy", Charlie on the case. He tells me that the mufflers the first shop put on were super el-cheapo, practically hollow with just one baffle. They were designed for maximum flow and maximum noise! Charlie created an H-pipe between the two downpipes, added much better mufflers, and brought the tips in a few inches. Everything was welded, great looking job. Now the car is nice and quiet, and looks better with the tips shortened. Cost me $500. I'm very happy with the result.
Now should I go back to the first shop and ask for my money back?

 

[Hubie]

Price sounds good. I need the same on my 67. Can you find out the Brand and part# on the Muffler?

 

[Scoopy G]

I'll call them Hubie and see if they can give me that information.

 

[3175375]

Thanks as always fellas for your advice. I took the car to the muffler shop yesterday, and got the "old guy", Charlie on the case. He tells me that the mufflers the first shop put on were super el-cheapo, practically hollow with just one baffle. They were designed for maximum flow and maximum noise! Charlie created an H-pipe between the two downpipes, added much better mufflers, and brought the tips in a few inches. Everything was welded, great looking job. Now the car is nice and quiet, and looks better with the tips shortened. Cost me $500. I'm very happy with the result.
Now should I go back to the first shop and ask for my money back?

Move forward and learn from the experience.

and pictures!

 

[jct]

Just leave them a bad review