Ford CMP muffler

[Jacques Reed]

Hello Hanno,

Attached are two photos of an original muffler as installed on a Ford Ambulance at the Bandiana Army Museum in Australia.

It shows the front end of the muffler very close to being in line with the rear step plate bracket.

The third photo is of an original rear bracket on my F15A. With my generic muffler installed, which is the same length as an original, the position is very close to the museum example. To prevent confusion from the photo, my tailpipe has an adaptor which mates the 1-5/8" tailpipe to the 2" outlet of the muffler. When installed, the adaptor fits inside the outlet and the smaller end goes into the bracket. The pipe was left a bit longer for fitting.

Something which is sometimes overlooked, which I have inadvertently done, when shopping for replacement mufflers is the position of the inlet and outlet relative to each other. My replacement one has the inlet and outlet 180 degrees apart.

The museum example shows the inlet at the 6 o'clock position when viewed from that end and the outlet at the 3 o'clock position when viewed from that end (90 degrees apart). I intend to juggle my exhaust pipe a bit to ensure it hangs properly but it would have been nice to have it all line up from the start.

Hope this is of some help in locating it on the truck and sourcing a correct one.

Cheers

[Private_collector]

Hanno,

I have contact details for a company in USA that can make an exact copy of original muffler. Just haven't found where I stored their details. May have posted their name onmy resto thread. Still looking!

[Private_collector]

Found the guy who can make your repro muffler to Ford specs.
http://www.ebay.com/itm/1932-41-FORD...38e891&vxp=mtr

He is still sellling on ebay, and the above link is to one which is already pretty close.

Hope it helps.

[Hanno Spoelstra]

Originally Posted by Private_collector

Found the guy who can make your repro muffler to Ford specs.
http://www.ebay.com/itm/1932-41-FORD...38e891&vxp=mtr

He is still sellling on ebay, and the above link is to one which is already pretty close.

Tony,

Thanks a lot, $100 is not a bad price but I'm sure the shipping will probably double that. I'm looking to buy locally.

Hanno

[Hanno Spoelstra]

Originally Posted by Jacques Reed

The museum example shows the inlet at the 6 o'clock position when viewed from that end and the outlet at the 3 o'clock position when viewed from that end (90 degrees apart). I intend to juggle my exhaust pipe a bit to ensure it hangs properly but it would have been nice to have it all line up from the start.

Jacques,

Certainly of help as I was wondering about the offset for the in- and outlet pipes.

Can you confirm the measurements listed by Tony W.: 6" diameter, 18" length, 2" inlet and 1-5/8" outlet pipes?

Thanks,
Hanno

[Jacques Reed]

Hi Hanno,

Those dimensions seem correct. A ford Truck manual for wartime trucks, not CMP type however, also gave the muffler dimensions as 6" Diameter and 18" long. Would reasonably assume the mufflers are the same. Ford tended to keep it simple and use off the shelf items whenever possible. By example: the choke and throttle knobs on the CMP being the same as used on their passenger cars of that era.

Two sets of original exhaust pipes also confirm that the muffler inlet ID is 2"

I cannot independently verify the 1-5/8" ID outlet on the muffler as I used Tony's information from brackets he supplied me, however the careful analysis of both original tailpipe and rear muffler brackets makes me 99% certain it is 1-5/8" ID. (1-3/4" OD pipe is too big a stretch in the brackets). A Dennis Carpenter Ford Reproduction car tailpipe bracket I have also indicates tailpipe sizes were 1 5/8" OD.

Hope this helps.

Cheers

[Stew Robertson]

Hi Hanno
I think there is a difference between 12 and 13 cabs
I have an original ford 12 pipe that the muffler slid over and
the muffler was welded on at each end
I will see if I can find the picture of the pipe

[Hanno Spoelstra]

@ Jacques, certainly helps! I have passed on the dimensions to my friend's local garage, he's sourcing a muffler for me.

@ Stew, I would be interested to see the differences between 12 and 13 Cabs. Could you make some pics?

Thanks,
Hanno

[Jacques Reed]

Hi Hanno,

Glad to help.

As a matter of interest here is the Chinnis Carpenter, I mean Dennis Carpenter passenger car tailpipe bracket in the jury rigged tailpipe bracket I made to get the position right.

The new tailpipe in it is 1-5/8" OD. As you can see it fits well and the next size up, 1-3/4" would be a stretch to get it in, let alone close it.

Having said that Dennis Carpenter so is not necessarily the final say on it. They do not always get it right, especially on their Chinese made stuff. The 5/16" carriage bolts in the brackets they supplied were UNC threads with a 13 mm AF nut! A 1/2" AF spanner would no way fit on it. Also going by the crossover pipe clamp on two original exhaust pipes I have they are both 5/16" UNF not UNC threads on the carriage bolts. Would reasonably assume they would use the same type bolt throughout to keep it simple. Maybe a minor thing but shows lack of research on their part.

Hope this is of interest.

Cheers

[Private_collector]

Just emailed the company in USA that builds custom muffers & exhaust systems.
If what I have read is correct, shipping to Aus is around $55 AUD.
At that price, I am happy to purchase. Muffler cost is $120.

The following, are the specs. I have taken from this thread, and my enquiry about supply is based on those requirements. If you feel any of those specifications are NOT correct, please let me know, and I will ammend my requirements to the manufacturer.

Specifications needed as follows:
Round Muffler with Domed Ends
Length: 18 inches
Width: 6 inches
Inlet pipe ID: 2 inches
Outlet pipe ID: 1-5/8 inches

Inlet pipe location: 6 o'clock (as viewed from inlet end of muffler)
Outlet pipe location: 3 o'clock (as viewed from outlet end of muffler)

I don't know if these would be any cheaper if multiples ordered, but I will ask, if anyone expresses an interest.