A/C muffler

[Jack H.]

Re: A/C muffler

I don't remember the conversation, Joe. But, current judging text teaches us to expect hoses with refrigeration clamps for 68-69E with the change to permanently crimped connections coming on-stream in late '69 production.

Plus all of the pix of '68 A/C equipped cars in the M.F. Dobbins book show the compressor manifold to be of the 'block' vs. 'binocular' style construction with dual Schraeder valves atop the block.

So, if I said that early Sharks had binocular style manifolds, I certainly can't find justification for such. However, flipping back a generation in M.F. Dobbins (mid-year cars), the binocular style manifolds are clearly in use...

This might be a nomenclature issue 'early vs. late' Corvette as opposed to 'early vs. late Shark'.

[Wayne M.]

Re: A/C muffler

or change to the light weight 3923139, with steel plate? Looks like a flat washer would work. ...... I am also curious about that steel support you spoke about, what it is, where its goes, and where to find one? ....

Dale -- I believe this is the steel reinforcing/backing plate that Jack H. mentions. Got this out of the boneyard. Of course, an aluminum manifold with outlet on the flat facing the rear won't work with this; has to be inlet/outlet from the bottom (or some other surface than rearward-facing).

Aside: this compressor is dated July 6th 1971 (1st shift) if I'm reading the tag correctly. Also, the back "6555302" cast head (without superheat connection) is dated E_20_1, but the mounting holes are drilled for metric.

[Joe L.]

Re: A/C muffler

I don't remember the conversation, Joe. But, current judging text teaches us to expect hoses with refrigeration clamps for 68-69E with the change to permanently crimped connections coming on-stream in late '69 production.

Plus all of the pix of '68 A/C equipped cars in the M.F. Dobbins book show the compressor manifold to be of the 'block' vs. 'binocular' style construction with dual Schraeder valves atop the block.

So, if I said that early Sharks had binocular style manifolds, I certainly can't find justification for such. However, flipping back a generation in M.F. Dobbins (mid-year cars), the binocular style manifolds are clearly in use...

This might be a nomenclature issue 'early vs. late' Corvette as opposed to 'early vs. late Shark'.

Jack------


I don't think we ever discussed it in a conversation. It seems like there was some thread on this quite a few years ago and that's where the issue came up. I only vaguely recall it but, somehow, I had gotten the impression from you that these "binocular" assemblies were the original configuration for early C3 and were extremely scarce. Admittedly, I didn't really pay a lot of attention since A/C stuff has never been of high interest for me and my recollection could be wrong by now.

[Joe L.]

Re: A/C muffler

Dale -- I believe this is the steel reinforcing/backing plate that Jack H. mentions. Got this out of the boneyard. Of course, an aluminum manifold with outlet on the flat facing the rear won't work with this; has to be inlet/outlet from the bottom (or some other surface than rearward-facing).

Aside: this compressor is dated July 6th 1971 (1st shift) if I'm reading the tag correctly. Also, the back "6555302" cast head (without superheat connection) is dated E_20_1, but the mounting holes are drilled for metric.

Wayne-----

The 6555302 plate dates back to 1962.

[Scott S.]

Did M.F. Dobbins midyear book change over the years?

Did the M.F. Dobbins book for 1963-1967 get updated over the years, with more pictures? Maybe even color pictures? I don't remember seeing any pictures of A/C compressors in the black & white midyear Vette Vues Fact Book, but mine is a second edition, 1977. Had it since I was a kid.


[Edit: I just checked one of the vendors, the M.F. Dobbins 63-67 Fact Book is in its 9th edition, with 378 pages. My copy only has 128 pages . I guess it's time to get the new one!]

[Dale C.]

Re: A/C muffler


Thanks to all
Dale

[Dale C.]

Re: A/C muffler

Wayne
Thanks for the picture, as you can see from that last picture of my flat surfaced muffler your plate design would probably work.
Dale

[Bryan M.]

Re: A/C muffler

Dale, can't fault you for going with your gut feeling. As other can attest, the 68s with an original unmolested a/c system are rare.

[Dale C.]

Re: A/C muffler

I am posting again because I save the pertinent threads and keep record of my questions. I just found out something that kind of adds to what Terry was saying about the binocular style being more a service oriented part. The Volunteer Vette Products book (page 165) shows support for the old binocular style 66 and 67, but not the elusive 68 only, 3923139. I still think for reliability the more service worthy square types made their way back in time to replace the less reliable and older binocular mufflers needing replacement, especially the even scarcer 68 model.

Thanks again
Dale

[Scott S.]

Re: A/C muffler

Dale,

According to the Corvette Black Book 1953-2009 (Antonick), there were 5,664 Corvettes with C60 / air conditioning produced in 1968, a substantial increase from the previous year (3,788 in '67, and jumped to 11,859 produced with C60 in 1969).

With 5,664 Corvettes produced in 1968 with A/C, it would seem that there has to be enough of them around in original condition for a meaningful sampling. What is the best way to target 1968 owners specifically, with a brief inquiry about whether their car has factory original A/C, and if so, what kind of compressor muffler was it originally equipped with? An attached picture of the part in question should eliminate any potential confusion.

How did Noland Adams (and other authors) carry out their various options sampling inquiries? However they did it, it might (ought to) be a lot easier and faster with modern technology. Even a tiny response rate from actual owners would probably be sufficient in this case.

[Dale C.]

Re: A/C muffler

Scott
Boy I would have to think about that. My wife says we Vette people are kind of anal and a project like that would be a tall mountain for me to climb. Just finding parts for a 68 is enough but trying to verify them also? I'll look around though.
Dale

[Terry M.]

Re: A/C muffler

Scott: The increase in 1969 C60 equipped Corvettes may be somewhat explained by the large number of Corvettes produced in that model year. Not all of the increase is explained by those numbers, but some of it.

John: If you want to take on the 1968 C60 research project, an ad in The Driveline might get you some responses. The traditional way we have done this kind of research has been through attendance at meets, and not just NCRS meets, but in the case of 1968s they appear so infrequently more aggressive methods may be necessary. Word of mouth will do wonders once other 1968 enthusiasts find out about your quest. You may eventually find 1968 owners contacting you and inviting you to view their cars. You will meet a whole new group of friends.

Traditionally restorers have had to do their own research when others have not already done it, so you are not alone in having to verify the configuration of various parts. There have been a number of 1968 enthusiasts here on this board, and what is now called networking can pay large dividends -- if you want to take the time and make the effort. You may have questions other than about C60, and a network of 1968 owners could quickly provide answers to all sorts of issues.

Others have done it -- it is how and why the various registries exist.

If you do decide to take on the challenge, I would suggest your first step is to contact the 1968-1969 National Team Leader, Chuck Berge. There is always a chance someone else has already plowed this ground, but lacks the ability or desire to get on this board. And Chuck may be able to put you in contact with some 1968 owners who can help you.

[Scott S.]

Re: A/C muffler

Scott
Boy I would have to think about that. My wife says we Vette people are kind of anal and a project like that would be a tall mountain for me to climb. Just finding parts for a 68 is enough but trying to verify them also? I'll look around though.
Dale

I wasn't thinking of anything complicated, although it certainly could be, depending on how much time and effort you wanted to put into it.

I was thinking of something fairly simple, along the lines of either doing a search of the C3 registry for '68 owners, copy-and-paste each available email, and send a broadcast email one time to however many 1968 owners you came up with. Even if it was just five or ten people, they would be exactly the right people to be asking. Attach a picture of the part you're checking along with a brief description of the problem you're trying to solve and then wait for the replies.

I'm not familiar with any of the Corvette registries yet (I'll get to it), but it seems like there was a way to contact people through the registry, at least those who volunteered an email address. A quick Google search turned up this one: http://www.c3vr.com/

You could also start a Thread specifically referencing the year 1968 (that might have helped with this Thread too) in the CF, the CAC and a few others, requesting that owners of '68s with factory A/C to step forward and sound off. If I was a '68 owner I would check a Thread with 1968 in the title, just because there are apparently so many things unique to that model year. It seems like half the battle is locating a few other people "out there" who have an original A/C system, and these methods (and others) shouldn't take too much time or effort.

I'm surprised no one from THIS forum with a '68 and original C60 has stumbled across your Thread yet. Between the several popular Corvette sites/forums, hopefully you could get enough replies that going the C3 registry/broadcast email route wouldn't even be necessary.

[Bryan M.]

Re: A/C muffler

I had a good collection of pictures that showed the 68 sb with a/c due to having owned one for 12 years. I gathered the pics from various sources.
Unfortunately, the pics are on an old computer that bit the dust. I will have to say that in most of the pics that the owner is touting originality, the car had the block type a/c muffler.

It would be great to have more 68 data. I always questioned if all the sb 68s with a/c had the idle solenoid set-up. Especially, the early 4-speed cars.

[Dick W.]

Re: A/C muffler

Just got back from looking at a fairly original '68 with C-60. It has the rectangular block..