A/C muffler

[Dale C.]

[Scott S.]

Re: A/C muffler

Dale, nice score!

For comparison, this one came off the '67. I don't know for sure if it's original or not (anyone?), but it has been on the car since at least 1977.

[Larry M.]

Re: A/C muffler

Scott:

Looks like an original 1967 model item to me. My 1967 factory air car has a similar manifold.

Larry

[Scott S.]

Re: A/C muffler

Scott:

Looks like an original 1967 model item to me. My 1967 factory air car has a similar manifold.

Larry

Thank you Larry, that's good to find out.


Dale, I tried a search on the '68 A/C muffler, but I only turned up Wayne Midkiff's Thread from June, with yours being the last (most recent) post in September (2009):
https://www.forums.ncrs.org/showthre...ffler&uid=9582

Yours appears to more closely resemble the '67 so that would seem a good indication that you found the right one, hopefully your original question will get a 'thumbs up' from somebody here who knows for sure.

[Wayne M.]

Re: A/C muffler

I finally found one, a 3923139 muffler for a 68 A/C compressor, see C60, D2. I asked about this puppy back last summer and got no response on it. I think the prior similar one was for “67” 3885128 where the left hose came straight out and aft, whereas this 68 3923139” comes down and then bends aft. ....

Dale --- Scott found my old post with the 3 pics (June 26 2009) before I could. Looking at my 1968 P&A30 catalog [1st issue Oct '67], it shows 3923139 as for 1968 Corvette only.

These mufflers seem to have been superceded quickly, as this same catalog shows muffler for '63 thru '66 (all) and '67 Corvete w/C.A.C. (427) (exc. Tri. Carb.) as number 3895917. What did the 400 hp C60's use ?

[Terry M.]

Re: A/C muffler

Dale,
I would expect to see the rectangular, or boxed type on original AC systems for 1969 to 1972. I think the connection tot he AC Compressor would be the same for 1968.

The style shown, commonly referred to as the binocular style, is a later (somewhat after 1972) SERVICE replacement.

BTW: Original muffler assemblies from 1968-1972 should have brass hexagonal rounded-top nuts that are tin plated. Some will have a manufacturer's logo on one of the flats.

[Dick W.]

Re: A/C muffler

Have to agree with Terry

[Dale C.]

Re: A/C muffler

Dick and Terry
If the boxed type were correct for production why is the reference in the AIM, for all three years 67, 68, 69, as being the binocular type with barbed connections for 67 and 68 and changing to the crimped type in 69? See pictures of AIM for each year. 67 left, 68 middle, 69 right.
Dale

[Scott S.]

Re: A/C muffler

Dale,
I would expect to see the rectangular, or boxed type on original AC systems for 1969 to 1972. I think the connection tot he AC Compressor would be the same for 1968.

The style shown, commonly referred to as the binocular style, is a later (somewhat after 1972) SERVICE replacement.

BTW: Original muffler assemblies from 1968-1972 should have brass hexagonal rounded-top nuts that are tin plated. Some will have a manufacturer's logo on one of the flats.

Hi Terry,

I'm trying to understand this, and the best photo reference I have available is Noland Adam's book (Vol. 2). It appears that BOTH styles were used, with the "binocular style" being more common:


Page 338 - middle picture (excellent close-up) - 1966 L36 engine with C60.
A/C muffler appears identical ("binocular" style) to the pictures above (please see post #2) from my Dad's '67. ONE hose connection to the "binocular" section.


Page 346 - only picture (very good top view) - 1966 base engine with C60.
A/C muffler appears identical ("binocular" style) again to the pictures above (post #2). ONE hose connection to the "binocular" section.


Page 392 - middle row, Right - 1967 base engine with C60.
A/C muffler appears identical ("binocular" style) to the pictures above (post #2). Looks like ONE hose connection to the "binocular" section.


Page 392 - bottom row, Left - 1967 base engine with C60.
A/C muffler appears different (square style, NOT "binocular" style) from the pictures above (post #2). Has a TWO hose connection to the "square style" part that connects to the A6 compressor.


Page 407 - top row, Left - 1967 base engine with C60.
A/C muffler appears identical ("binocular" style) to the pictures above (post #2). ONE hose connection to the "binocular" section.


Page 407 - top row, Right - 1967 base engine with C60.
A/C muffler appears different (square style, NOT "binocular" style) from the pictures above (post #2). Has a TWO hose connection to the "square style" part that connects to the A6 compressor.


Page 407 - middle row, Left - 1967 L79 engine with C60.
A/C muffler appears identical ("binocular" style) to the pictures above (post #2). ONE hose connection to the "binocular" section.


Page 407 - middle row, Right - 1967 L68 engine with C60.
A/C muffler appears identical ("binocular" style) to the pictures above (post #2). ONE hose connection to the "binocular" section.


Page 407 - bottom row, Left - (other side of left middle row L79 engine car) 1967 L79 engine with C60.
A/C muffler appears identical ("binocular" style) to the pictures above (post #2). ONE hose connection to the "binocular" section.


Page 407 - bottom row, Right - (another view of right middle row L68 engine car) 1967 L68 engine with C60.
A/C muffler appears identical ("binocular" style) to the pictures above (post #2). ONE hose connection to the "binocular" section.


I think that makes 10 pictures from 8 different cars (1966-1967) in the Noland Adams book, with only two (2) having the "square style", both on base engine cars. I don't know what conclusions can be drawn from this (if any), I'm just pointing out what I found in the only book I have with pictures of the specific part in question.

[Terry M.]

Re: A/C muffler

Dick and Terry
If the boxed type were correct for production why is the reference in the AIM, for all three years 67, 68, 69, as being the binocular type with barbed connections for 67 and 68 and changing to the crimped type in 69? See pictures of AIM for each year. 67 left, 68 middle, 69 right.
Dale

Lots of the drawings in the AIM are not accurate. You can not rely on fastener head drawings, clamp configuration, and many other drawings -- especially when the part number changes and the drawing doesn't. The AIM drawings were for the workers to assemble the car, not for them to identify the parts they used. They used the parts they were supplied.

This is also why one can identify typical factory production from original cars. ALL the parts books and AIMS and even TIM&JGs are only tools to confirm the originality of the cars. They all contain errors. One must do due diligence to determine what is accurate and what is not.

BTW: I am pretty sure the 1968-69 TIM&JG describes the AC manifold with a block shape, and I know the 1970-72 does.

[Larry M.]

Re: A/C muffler

Scott:

See my earlier #3 post. My car is lo mile (26,000) with the original dated A-6 compressor and correct dated/logo hoses. The chance is REMOTE that my compressor block is not original to the car....and it is the binocular type as shown in the 1967 AIM and in Noland's book.

The 1968-69-70 etc C3 cars may be different, which is what Terry and Dick were saying based on their knowledge and experience. The C2 and C3 cars do not all have to be the same. There were many differences even in very similar components between the two models.

Larry

[Scott S.]

Re: A/C muffler

Scott:

See my earlier #3 post. My car is lo mile (26,000) with the original dated A-6 compressor and correct dated/logo hoses. The chance is REMOTE that my compressor block is not original to the car....and it is the binocular type as shown in the 1967 AIM and in Noland's book.

The 1968-69-70 etc C3 cars may be different, which is what Terry and Dick were saying based on their knowledge and experience. The C2 and C3 cars do not all have to be the same. There were many differences even in very similar components between the two models.

Larry

Thank you Larry,

I was confused when I read Terry's comments that the "binocular style" was a later service replacement (post-1972), and then confused more when I checked the Adams book and the pictures of the midyears showed both kinds.

If I understand better now, it seems that the binocular style was correct at least up to 1967. I don't know why the square or "block" style appeared on two midyears in the Adams book.

The picture of the part Dale originally posted is different from the "block" or square style seen in two of the Adams book pictures, and also different from the binocular style in the majority of the Adams book pictures.

So I am still unclear about what the correct, original part looks like for the 1968, related to Dale's original inquiry.

I didn't mean to take this Thread off in a different direction, I'm just trying to understand.

[Dale C.]

Re: A/C muffler

Larry, me too on the trying to understand. I have a very unique AIM as it's an origional and not a reproduction and showes the C60 for the 68 as I posted above. They could not have shown a 72 or later in 68, so there was one of these binocular 3923239 hanging around in 68 and it was different from the 67 version and also used the old clamps and not the newer style crimped on hoses.
Dale

[Wayne M.]

Re: A/C muffler

Thank you Larry,

I was confused when I read Terry's comments that the "binocular style" was a later service replacement (post-1972), and then confused more when I checked the Adams book and the pictures of the midyears showed both kinds.

If I understand better now, it seems that the binocular style was correct at least up to 1967. I don't know why the square or "block" style appeared on two midyears in the Adams book.

The picture of the part Dale originally posted is different from the "block" or square style seen in two of the Adams book pictures, and also different from the binocular style in the majority of the Adams book pictures.

So I am still unclear about what the correct, original part looks like for the 1968, related to Dale's original inquiry.

I didn't mean to take this Thread off in a different direction, I'm just trying to understand.

Dale, Scott, Larry et al. First of all, Scott, very good analysis (I needed a magnifying glass) of those C2 pics in Noland's Vol 2. But those two that you call "square" are flat plates (not a manifold) and are surely aftermarket. This leaves us with the '66 and (other) '67s. The '66s have the "binocular" style (love that term ) and have a Schraeder valve on both sides in a horizontal plane (ie. facing motor and facing RF tire). It appears that for 1967, they eliminated the inboard Schraeder valve (this surprises me).

As for 1968, my old post showed what I bought from the dealer in the early '80s, but it had the GM tag with #3923139 on it, so I just assumed it was also TFP for 1968, and SERVICE for all prior years (as of the 1970 catalog).

AIM's are notorious for not updating the artwork any more than necessary. Example is 1965 where they show a muffler assembly that resembles a 1963 style, or (maybe) 1964, but not 1965, which was "binocular" with outboard valves. Mind you, they do list an optional manifold, but the primary number 3826079 updates to 3885128 by Jan of 1966 (for service), and this number updates to 3895917 by Dec of 1966. This latter may be the '67 AIM listing with ONE outboard Schraeder valve.

I'm really surprised that more original '68 owners have not jumped in here.

[John H.]

Re: A/C muffler

The '66s have the "binocular" style (love that term ) and have a Schraeder valve on both sides in a horizontal plane (ie. facing motor and facing RF tire). It appears that for 1967, they eliminated the inboard Schraeder valve (this surprises me).

Wayne -

That's correct. Both '66 and '67 used the "binocular" style of muffler block, with the inboard valve deleted on 67's.