Vintage Double Hose

Has anyone put together a timeline for the various Dacor double hose regulators? What year did Dacor stop cataloging these regulators?
Thanks for any info.
Allan

Model R1 - 1955-1956
Model R2 - 1956-1959
Model R3 - 1959-1962 (with Dial A Breath)
Model R4 - 1962-1973
Model C2 - 1963-1966
Model C3 - 1966-1974
Model C3N-1974-1982

Address: Evanston (1955-1959) / Skokie (1959-1970) / Northfield (1970-Today(Mares))

More pictures: cg-45.com/index.php?option=com_content&view=category&layout=blog&id=112&Itemid=675&lang=pt

Thanks.

Adairrj

I see the R-1 and the R-2 predate the dial a breath. What are the differences between the R-1 and 2?

Jim

swimjim wrote:Adairrj

I see the R-1 and the R-2 predate the dial a breath. What are the differences between the R-1 and 2?

Jim

Hi Jim,
Just the label...they are identical!!
R-1

R-2

Thanks Adairrj! I had one that the serial number was around 1500. I was raising money for a project and sold it via ebay to a fellow in Japan for $350.00 US. It was a sweet example. It looked like it was never used.

simonbeans wrote: What year did Dacor stop cataloging these regulators?
Thanks for any info.
Allan

Here is a copy of page 12 of the 1978 Dacor catalog. Sorry for the poor copy. This is the latest catalog I have.

The Model C3-NB (Balanced) was cataloged in 1978 and other years. But there are no records of this model. The C3-NB was listed on a performance chart published by U.S. Navy Diving Unit Experimenatal, along with 36 other regulators (Historical Diver - Summer 2002, No. 32 - Volume 10 Issue 3)

I recently acquired what I think is a very early Dacor R3 with the Dial a Breath feature. Serial # is 6231, which is the earliest number I have seen for Dial a Breath. Anyone care to date it? I know that the Dial a Breath was announced in April of 1959. It has the original 1" hose loop and breathes between 'like a pig" and 'like a stuck pig".

Oink

The DACOR one inch hose loops are great for display and not much else. DACOR regulators in general were built Bullitt proof and heavy duty. Put a US DIVER hose loop on the reg. Dive it about four or five times. You will notice every time you dive it, the reg gets better. This has been MY Experience. The 1st stage diaphragms used in DACOR regs were heavy duty and stiff as my back after a dive weekend. The more exercise they get, the better they will perform. DACOR made really good regulators. Regrettably they are like us and get stiff, really stiff, with age. The only way to correct this is with exercise.. DOH!
I have a DACOR Clipper 2 that will breath just as well as a DA Aquamaster with all the new parts. You want to try it? Great. Unfortunately, I need new parts too and won't be diving again until 2022.

Jim

Thanks Jim,

One old, stiff mossback in need of exercise is probably enough for my house. I will take your advise and use a USD hose loop to see if it helps. The original tinnermans are in great shape as are the hoses and Dacor marked mouthpiece. I'm not too sure about the wagon wheels and mushroom valves. Hoses are stiff as an old tire and look like they might be an early experiment in radial tire technology. Probably best to test this in water deep enough to stand up in.

George

I've been rebuilding a bunch of Dacor regs lately. I ran into a source of parts and have been able to complete a few that were languishing in the bin. I got a few more complete regs as well. They are R-2s, R-3s, and R-4s. I was able to get some NOS main diaphragms, some good used diaphragms, NOS HP diaphragms, NOS exhaust mushrooms, NOS non-return valves, and some mouthpieces with wws, in both sizes.

It has been interesting to see this new stuff, and to take the regs apart. One thing that is striking is the different styles of main diaphragms. They are not all the same. There are early domed, later domed, and accordion pleated (of possibly two types). There are upside down domed exhaust diaphragms. There are several kinds of plates on them, as well.

Some are very flexible, and some have stiffened up with age. The stiff ones are recently removed from a regulator. The stored ones are nice and floppy. The Dacor diaphragms were not stiff when new, unlike the hoses which were rather.

The reason Dacor 2500s don't perform as well as a DAAM or some other 2 stage regulators is due to the simple second stage. Making matters worse, the R-1s and R-2s were made with the second stage positioned 90 degrees away from the intake horn.

The R-3 is a bit better. They positioned the second stage in front of the intake horn, making a more direct path into the intake. The second stage orifice is simply a drilled through bolt with a cone on top. A lever with a seat on the end seals it. The air jet from the second stage is blown into the face of the LP seat, and disperses into the box.

Coupled with the 1" mouthpiece and tiny, buried non-return valves, this all makes a fairly hard breather. Why they thought they needed to throttle the things even more with the dial a breath vane....

The R-4 can breathe as well as a DAAM due to its redesigned second stage. Part of the problem with R-4s is the second diaphragm. If you replace it with a duckbill, the exhalation effort is improved. The other problem is the too small mouthpiece with its small non-return valves. It is way better than the 1" set, but things are easier with a USD hoseloop. They called the larger mps 1 1/2", but they are significantly smaller than USD 1 1/2" mps.

I've had some C-2s, C-3s, and C-3Ns that are fine breathers, and they are basically no different than the R-4. In fact, the C-3N is a beefed up R-4 with a duckbill instead of a second diaphragm.

I have a great article that goes into the history and timeline by models, years, serial # ranges, design changes, etc. I will send a pdf to anyone interested. Send an email and I'll get you a copy!

According to the HDS's History of DACOR article [Vol. 23 No. 83 of The Journal of Diving History], the Dacor Diving-Lung series 2500 models R-2 and R-3 used the same exact can and label. R-2 regulator serial numbers ran from 2140 until 7756 with R-3 [Dial-A-Breath] serial numbers running from a verified low of 7876 until 34068.

This could mean a couple of things: 1) I have a very early, prototype Dial-A-Breath or [and much more likely] 2) in the 60+ years from when my regulator left the factory until I acquired it, the can was replaced with an earlier one, probably during servicing.

So it is probably just an early Dial-A-Breath with the 1" hose, and an R-2 can and label, rather than with the proper R-3 can and label. Produced sometime between spring of 1959 and the 1961 date when DACOR switched to 1 1/8" hoses.

By R-2 can and label, are you talking about the cover? The R-2 and R-3 used the same label and cover, but the mechanism box is different.