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Discussion of diving methods and equipment available prior to the development of BCDs beyond the horse collar. This forum is dedicated to the pre-1970 diving.
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Bronze06
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Joined: Tue Jul 01, 2014 5:33 am
First Name: Russell
Location: Tabuk, Saudi Arabia

Siebe Gorman/Heinke Mistral

Fri Dec 02, 2016 11:53 am

I aquired a very nice Siebe Gorman /Heinke Mistral and it just came in today. WOW! This regulator had some dust and dirt, but over all condition is 9 out of 10. It has less than 1% verdigris and chrome loss. I believe it to be from around 1962, due to its having the SPG /Main body platfrom that support the internals as well as the blue and white recessed sticker. The mouth piece says: "Heinke London" which would also correlate to this being a third generation Siebe Gorman.

The interior was fantastic. Man, those Brits went full tilt on quality and in my opinion this regulator is hands above even the Drager PA-61, which is no slouch of a reg. You can tell that someone really loved this reg at one time and it was taken care of in a most excellent way. Here are the pics. :D
siebe 1.jpg
siebe 2.jpg
20161202_151625_resized_1.jpg
This is going to be an easy and fun rebuild!!!
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"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

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8dust
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Location: Nashville's North Shore

Re: Siebe Gorman/Heinke Mistral

Fri Dec 02, 2016 12:33 pm

Wow, VERY nice. Great internal shots. Super helpful to see how the SPG pipes-in to the single stage. I hadn't seen that before.

I've always liked the hard elbows on those and they seem like a pretty good idea to take some pressure off the hoses at the junction to the horns. Really like the 4 screws for closing up the cans too! Does it seal up as flat & tight as a band clamp? Sure would be quicker... Also have wondered about the "jaw feel" of those down-facing hoses and if they are more or less comfortable than a USD curved MP?
Freddo
NAVED member #201

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Bronze06
Master Diver
Posts: 666
Joined: Tue Jul 01, 2014 5:33 am
First Name: Russell
Location: Tabuk, Saudi Arabia

Re: Siebe Gorman/Heinke Mistral

Fri Dec 02, 2016 6:51 pm

8dust wrote:Wow, VERY nice. Great internal shots. Super helpful to see how the SPG pipes-in to the single stage. I hadn't seen that before.

I've always liked the hard elbows on those and they seem like a pretty good idea to take some pressure off the hoses at the junction to the horns. Really like the 4 screws for closing up the cans too! Does it seal up as flat & tight as a band clamp? Sure would be quicker... Also have wondered about the "jaw feel" of those down-facing hoses and if they are more or less comfortable than a USD curved MP?
I haven't dove it yet my friend. I will answer your questions the moment I do.
"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

regulatorbj
Skin Diver
Posts: 38
Joined: Wed Jan 05, 2011 11:51 pm
First Name: john
Location: Honiton UK

Re: Siebe Gorman/Heinke Mistral

Fri Dec 02, 2016 8:35 pm

Congrats on your find

If you email

[email protected]

will forward more information on the build types and years of the modifications and drawing etc
I always have problems att pix to the posting

the Siebe Heinke mouthpiece has to be set up correct otherwise it has a tendency to be very uncomfortable in use.


john68

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Bronze06
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First Name: Russell
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Re: Siebe Gorman/Heinke Mistral

Sun Dec 04, 2016 8:49 am

regulatorbj wrote:Congrats on your find

If you email

[email protected]

will forward more information on the build types and years of the modifications and drawing etc
I always have problems att pix to the posting

the Siebe Heinke mouthpiece has to be set up correct otherwise it has a tendency to be very uncomfortable in use.


john68

John,

Tried the e-mail and it isn't working for me here in Saudi. I went to Scubaboard and found some neat stuff. My e-mail is [email protected]

Thanks, Russ
"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

reddiver
Lung Diver
Posts: 64
Joined: Tue Mar 08, 2011 11:10 pm
First Name: David
Location: Youngsville,NC

Re: Siebe Gorman/Heinke Mistral

Sun Dec 04, 2016 12:31 pm

HI Russ,
Your post reminded me that I have a SIebe Gorman Mistral waiting to be rebuilt. IT is in pieces but I believe that parts are all there except the hoses, mouthpiece, and elbows. Do you have a schematic on this ? I have a yellow label "Siebe Gorman Chessington Surrey" . If I find some elbow connectors for the hoses, can I use a regular DAAM hose set up ?

Red Diver

regulatorbj
Skin Diver
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Joined: Wed Jan 05, 2011 11:51 pm
First Name: john
Location: Honiton UK

Re: Siebe Gorman/Heinke Mistral

Sun Dec 04, 2016 3:02 pm

Will try your posted email


john68

regulatorbj
Skin Diver
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Joined: Wed Jan 05, 2011 11:51 pm
First Name: john
Location: Honiton UK

Re: Siebe Gorman/Heinke Mistral

Sun Dec 04, 2016 3:06 pm

Hi reddiver
have drawing for your SG "Yellow Plate"if you email posted above will forward document.

john 68

reddiver
Lung Diver
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Joined: Tue Mar 08, 2011 11:10 pm
First Name: David
Location: Youngsville,NC

Re: Siebe Gorman/Heinke Mistral

Mon Dec 05, 2016 3:47 pm

My E;Mail is [email protected]

Thanks
Dave (REd diver)

regulatorbj
Skin Diver
Posts: 38
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First Name: john
Location: Honiton UK

Re: Siebe Gorman/Heinke Mistral

Tue Dec 06, 2016 6:36 am

rediver
Have emailed with SG information

john68

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Bronze06
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First Name: Russell
Location: Tabuk, Saudi Arabia

Re: Siebe Gorman/Heinke Mistral

Thu Dec 08, 2016 11:03 am

regulatorbj wrote:Will try your posted email


john68
Thanks for the info again John.

It came in real handy for the rebuild. It was fairly straight forward and in most aspects it is 90% like a US Divers "Mistral". Things that ARE different are the actuator pin for the first stage. It is larger and beefier and has the pin retaining seal placed in a groove around it rather than inside the main reg body as per a Spirotechnique or US D Mistral body ( I was just able to squeeze a AS568-003 o-ring onto it and with a little silicon grease thump it gently into the body using a plastic hammer) . The yoke is fricken massive and could easily take 3500 psi. The serial number of the reg is on the yoke.

Inside the built in SPG port is a finely turned brass shut off screw that only should be removed IF you plan to actually use an SPG hook up with the reg. Due to the SPG port's placement on the reg body, you will either have to use a pillar tank valve of look for a K valve that will allow the reg to fully seat onto the tank orifice, or it will bump up againts a modern Sherwood valve.

The main HP seat is approximately 3/8ths of an inch longer and has a longer and larger diameter spring, approximately 1 millimeter larger in diameter than a USD spring from Bryan and has thinner walls due to spring size being larger in diameter. A US Divers Mistral seat could be used, but you will need to bore it out to allow the larger and longer spring to work efficiently, making sure you get your spring height to seat body length correct first as per original combined seat and spring length. Exterior seat side and facing dimensions are compatible with a US D Mistral seat. The machined horns have 1mm thick by 21mm interior by 24mm exterior flat seals, but you can use a lightly greased AS568-211 o-ring as a truly viable replacement and allow for ease of adjustment of the horns.

I have used a new silicon main diaphragm as opposed to the original (which was in great shape). The issue here is getting the can clamps to seal the cans up due to the orignal diaphragm's thicker dimensions.This was solved by adding heavy gage military rolled aluminium foil to the curlled lip of the exhaust can just underneath the can clamp to bolster the loss of material and seat the can clamps so no movement would take place. All that said, a new SS retaining band would work just fine.

Lever height is adjusted from the lever support body (Lever frame) to 1/2inch and works great with either the original diaphragm or a new silicon one. The lever adjustment wheel is secured to the body in the same way as a US D, but it has a flat tip slot for a screwdriver rather than a hex head. I didn't look to see if a US D hex post and screw would work as the original was in excellent shape and showed NO apparent wear. The seating nut and adjustment post were both in almost like new condition. I doubt that this reg ever saw salt water, or was in fact religiously maintained if it indeed did see salt water. Chromework on this reg was on an order of magnitude higher than any reg I have rebuilt. Just outstanding!

With regards to the mouthpiece, I have cleaned it and have replaced the mushroom valves with new ala VDH as well as installed Bryans new 1in. by 1 and 3/4 EPDM hoses. With the so called reverse mouthpiece the EPDMs are a plus. Did a tub check and no reg leaks at 3300 psi. Excellent breathing. Let it sit under pressure of 3300 for 12 hours with no apparent pressure loss from the HP seat. Pool dive to follow most likely this weekend.
"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

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Bronze06
Master Diver
Posts: 666
Joined: Tue Jul 01, 2014 5:33 am
First Name: Russell
Location: Tabuk, Saudi Arabia

Re: Siebe Gorman/Heinke Mistral

Thu Dec 08, 2016 11:26 am

reddiver wrote:HI Russ,
Your post reminded me that I have a SIebe Gorman Mistral waiting to be rebuilt. IT is in pieces but I believe that parts are all there except the hoses, mouthpiece, and elbows. Do you have a schematic on this ? I have a yellow label "Siebe Gorman Chessington Surrey" . If I find some elbow connectors for the hoses, can I use a regular DAAM hose set up ?

Red Diver
Hi Red,

I thought about that very same thing. What I would do is is cover up the machine screw portion of the horns with a section supple material like BICYCLE innner tube, possibly electrical tape or fill the groves with silicon sealant and let it set over night and then gently with a little bit of cooking oli slide your hoses onto the horns. This or something like it should be done to reduce wear on your hoses and I am sure that if properly secured and centered hose clamps would work. I seem to remember someone posting homemade plumbing fittings onto a Siebe as well. JMO
"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

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8dust
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Posts: 551
Joined: Wed Aug 05, 2009 11:39 am
Location: Nashville's North Shore

Re: Siebe Gorman/Heinke Mistral

Thu Dec 08, 2016 3:39 pm

Thanks for the report, Russ :)
Freddo
NAVED member #201

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Bronze06
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Joined: Tue Jul 01, 2014 5:33 am
First Name: Russell
Location: Tabuk, Saudi Arabia

Re: Siebe Gorman/Heinke Mistral

Sun Dec 11, 2016 10:39 pm

A few more notes:

I replaced the mouthpiece retaining bands with new ones a la VDH due to the original metal ones being rather frail. Suprising since everything else on this reg is seriously over-engineered. Luis probably loves this reg. :D

The mouth of the main body where the HP seat spring and sintered filter enter has a threaded retaining ring insted of a compression ring as in the USD and La Spirotechnique regulators. I guess the Brits really liked to do a lot of tool and die work. It has 4 cross hatch marks to allow a flat piece of metal to unscrew the ring from the body. I uses a flat fork handle to access the internals and it worked just fine.
20161212_054429.jpg
I dove it this weekend in 15 ft. of 58 degree water using a 1955 USD Rene tank and pillar valve. (video to come out soon.) If it wasn't for my having a Banjo fitting I would not have gotten the reg on. The regulators breathed like a champ at 2250 psi and Bryans EPDM hoses are the shizznick. I decided to go along with the British over-engineering theme and added two SS clamps ot the horns from an M1 Abrams tank cooling system. They are also over-engineered, but are easy to use and built like a "Tank" dare I say.

I now believe that mine is the 1963 era 3rd generation due to not only all the above, but it has its original venturi, which is a short venturi as in the 1st and 2nd generations. GENS 4,5 and 6 had an extended venturi that went right into the inhalation horn.
20161212_052703.jpg
The SPG port would make this reg very hard to attach to a single tank regardless of who makes the valve. I believe now that these particular regs were designed specifically for dual tanks.
32.jpg
I did an experiment with my Faber 3442 duals at 3400 psi and the reg breathed very hard. This was probably to to excessive pressure. I opened the reg up and adjusted the actuating levers a little higher which helped a bit but the reg still was a hard drawing reg unti the tank pressure got down to about 2900psi. I have heard of this happeing to others using single stage regulators, but this is the first time it has happened to me. It is just a guess, but due to the larger dimensions of the HP seat, the HP seat has a larger surface area and thus has more pressure applied on in as opposed to a USD or Spiro type HP seat.
By the way, the reg has no problems with a dual tank valve and total clearance was achieved with the SPG port, which deffinitely supports my theory that this reg was designed for duals. I also seem to remember that Sibe made regs either for single or double tanks. If anyone has more information regarding this please chime in.

Thanks, Russ
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"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

User avatar
Bronze06
Master Diver
Posts: 666
Joined: Tue Jul 01, 2014 5:33 am
First Name: Russell
Location: Tabuk, Saudi Arabia

Re: Siebe Gorman/Heinke Mistral

Wed Dec 21, 2016 8:41 am

"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"

Live From the Red Sea,

Russ

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