Vintage Double Hose

Been looking at the C3 and R4 dacor doublehoses...pulled the schematics off Bryans downloads and am curious.....

C3 I understand is a unbalanced 2 stager.....but the R4, if my readings from the drawings is correct, is also an unbalanced 2 stager.......is this correct?

What purpose does the double diaphragm have on the R4?, Exhaust goes thru the second dia. and past a mushroom.......why? Why change the simple exhaust flutter valve of the C3?

I suspect the multiple linkage of the 2nd stage main dia levers in both the C3 and R4 produces enough resistance that it isn't as sensitive with cracking pressure as the RAM, is this also true?

Any insight will be appreciated, before I spend any hard earned cash....

This is just my OPINION and I know I’ll get some grief from some folks, especially Rob. I had 0 experience with Dacor double hoses….But a few years back they were plentiful and at that time pretty cheap. I purchased 3 R4’s with the intent of building parts kits for them and working on performance enhancements. My results came out like this.
1. Dacor double hoses are built TOUGH! Built like a Tiger tank. Hoses and all.
2. Parts were fairly easy to reproduce. Except the LP seat (crucial) which looks like a small round ball cut in half….I tried and tried and never came up with the right durometer of rubber that I was happy with.
3. I could never get one to breathe in the league of even a DA. I tinkered and fooled around with all sorts of lever height adjustments and various other things but nothing much helped. I attribute this to two things.
a. I don’t know my a** from a hole in the ground when it comes to Dacor double hose regulators.
b. The two main rubber diaphragms were either too stiff to begin with or had gotten that way with age. I had no new ones to compare them to. I was able to source some exhaust valves that would work that were used in modern BC overpressure valves.
4. The 1” valves in the Dacor mouthpieces are too small to provide adequate air flow. Once again this is only my opinion. I found the beasts much easier to use with USD hose and mouthpiece assemblies.
5. Dial A Breath….Marketing ploy IMO….

I did get a lot of Dacor doublehose parts in a big lot of parts I purchased. All except a bag of high pressure seats were given to Jerry Powell….AKA Dacor Jerry. He is the whiz with them as he worked as a tech for them for many years. He has a busy schedule and does not post much. I’m sure that Sea Hunt Jerry or Dan can tell you how to reach him.
I hope they are some others out there that can be more helpful but I thought my lessons from losses might save you some time and some coin….

Sorry to ramble on so much! I'm starting to sound like Helmet Boy and lord knows I don't want that!!

When I started diving in the early 60's I usually dove with 4 other kids my age. One had an USD Aquamatic which has been discussed far beyond my affection for that reg. My best buddy had something in the USD single hose group, but I can't remember what it was. The other two divers was a brother and sister. They had the Dacor Dial-a-breath. Tom, the brother died a decade or so ago as a bush pilot in Alaska and his sister, Sandy (I think) was the gorgeous long-legged beauty we all wanted as a dive buddy. Those Dacors were on a par with the Aquamatic, like sucking syrup through a straw. But, and this was the memory that has lasted, that extra inhalation effort really gave Sandy some beautiful lungs. See, Dacor did have a better idea. About the double diaphram concept, well, let's leave that for another tale.

I heard once that they used the double diaphragm thing to avoid patent infringements, but that is just what I heard.
I had a diving lung for years and I thought it rocked but the stiff dacor hose, though virtually indestructable, were too stiff and short.

To reach Jerry, his email is [email protected] Like said,he works his regular job, long hours, but tries to work in rebuilding a regulator when he can. He is a very nice person and a pleasure to deal with. William

Thanks guys for the replys.........judging from your comments, the linkage does hamper the sensitivity of cracking effort and with the unbalanced 1st stage it seems these regs don't have much going for them.........I'm surprised they were the last ones built.........

I'm diving with a R-4 in this picture ... It's in almost new condition. I now dive exclusively with an Aquamaster DA; mainly because the R-4 has no hooka port and as others have mentioned, the hoses on the R-4 are shorter snd stiffer. I think the eshuast diaphram of the R-4 last a lot longer than a duckbill valve so requires less replacement. One time I was overweighted while diving at Whiskeytown Lake with the R-4 and had fun inflating my bc on the surface. That was the last time I dove with the R-4; 'cause my DA has IP going to my power inflator ... problem solved. I'd probably take my "new" mistral diving before I'd use the R-4 (although the new mistral sits in my bedroom until I can find someone to off load it on, that will pay me enough for it (I paid $700 for it), that doesn't know the problems with these new sort of double hose regs). Oh... almost forgot... all I said is my opinion on things ...

I try to be honest, fair, open-minded, and reasonable. I don't always succeed, but I try. I often get my neck hacked when I stick it out for the other guy. That's life.
So here's the thing. Are you guys now telling me that the myth that double-hose regulators are hard-breathing may actually be true?! Let's be honest with ourselves and everyone else. Instead of tearing into the next guy who says that to you, make sure you say, "You're right..........for some models." Then proceed with the educating.
Now, shred me to bits!

Whew! I'm glad I made it back to my last post before anyone replied!
I posted it late last night when I was quite tired and now I have reread it. Let me say that if there were a "nudge, nudge- wink, wink" smiley I would have used it. I meant to say what I said half in jest. I'm in the same boat. I have never experienced a hard-breathing regulator, but then all I've used are USD. I've never used a Dacor (or, I assume, others like one of the older Healthways perhaps) so it's good to know about the experiences posted here. Next time I talk with someone who says double-hosers are hard breathing I will first ascertain whether they have experience from which to speak, or if they are commenting from heresay. If they actually have experience, I will find out more about what regulator they were using or how good their memory is . Apparently, it isn't ALL related to regulator positioning. According to this thread there really ARE hard-breathing double-hose regulators out there inherently made so due to their original designs. This is news to me. I'm humbled.

Terry,

If you want to you can try out my Dacor R-4 sometime and I think you will see a notable difference between it and a DA or RAM.

Robert

Thanks for the offer Robert. I'll plan on taking you up on that this Summer. I'm really curious now. We can also drill on inflating BCs underwater without auto-inflators

Terry,

Ok on that. Tomorrow I'm going to check out the Feather River. Been rumors floating around that a couple of trees fell last winter blocking our favorite entry spot and there is still alot of current due to snow melting ... got to see for myself. I'm hoping there isn't too much work clearing the trees out ...

Robert

I have a Dacor Diving Lung and I'd have to say its like sucking syrup through a straw like Simmonbeans said. It doesn't hold a candle to my DA or even my Healthways (Brownlabel mid sixties vintage) . I still take it out to hack around in the shallows once in awhile. Oh yeah, It's got dial a breath which really dosen't seem to do much of anything.

Jim

I've had the pleasure of tinkering with an R-4. I was able to source out NOS parts for it and it came out really nice. Yes, they are built like Russian Tanks! Yes, they do breath stiff! Yes, USD hoses and mouthpiece does do wonders for it. No, not enough to make it equal a Mistral, DAM or RAM. I have since sold that gem to one of our members of the Vintage Diving Community. It was later sold on Ebay from which it originally came since. That reg will keep working for the next 20 years given that I rebuilt it with NOS parts. I even included an extra set of diaphrams and HP seat for future rebuild. Stick with USD/Aqualung if you want to dive with a DH reg. I've yet to find anything more enjoyable barring my homebrew O2 rebreather.

Re: that "homebrew O2 rebreather" comment. I know this probably belongs on another post/site but, how does that saying go? -- One mistake and the Ocean will take them. Homemade rebreathers are lots of fun but just be careful, OK? Many experienced divers with "advanced" equipment have been taken.

The RAM is tops in my book.