WWII era Stromberg[?] aircraft float-type carburettor – can anyone help identify?

Hi Ed,
I’m sorry I forgot to put in the bolt hole measurements in my last message.
The mounting flange is somewhat cracked & bent with only three bolt holes remaining intact or close to intact, so the measurements may not be 100% accurate I’m afraid. [and I measured in mm so please bear with me….] I got 11 mm for the diameter of the holes, pretty close to 15/32″; distance between holes on the short side was an estimate due to missing corners – I got ca. 100 mm / 3 15/16″; and the distance between holes on the long side was ca. 110 mm centre to centre of hole or ca. 99 mm edge to edge of hole, so kind of flanking the 4 1/16″ measurement.
I’m also not sure if it is a six bolt hole flange; the centre of one long side is severely cracked when the hole would’ve been but I’m not certain I can see evidence of said hole – were there 5 bolt hole flanges?
Thank you for looking for the Stromberg book. Dogs do have a habit of eating things like that I find! 🙂
Thanks again for your help 🙂

CarolineW,

The mounting flange for the “12” is; 3 3/4″ dia. barrel; 4 1/16″ between bolt holes on the long side, 3 15/16″ between bolt holes on the short side. It is a six bolt flange. The holes should be 15/32″.
The Wasp engine (Wasp A up to the Wasp H) took the NA Y7 thru NA Y9 carb. (By the way, Wasp = civilian model, R-1340 = military model, the civilian used a letter, the military used a number after the Wasp/ R1340 designation. There are very few anomalies in this designation, but P&W changed format a number of times) I can not wax eloquently on the Twin or Double Wasp’s. I am looking for my Stromberg book. Seems my dog may have eaten it. Will keep looking.
Ed

Hiya Ed,
Thank you so much for your response.
Based on your info and the Stromberg naming / numbering system, I’m reaching the tentative conclusion that my carb is a NA-L12. It’s definitely float & downdraft, and having barrels to one side of float chamber – which in my understanding, now that I can definitely rule out “Y”, leaves only the “L” series as a possibility [?]. The 12 size seems to fit, if I’m calculating correctly…. the barrel opening is 3 3/4″ and the throat is 3 1/8″ [as best as I can measure it] – does that sound right based on the SAE standards?
I’m still completely lost re. what type of engine it may have been fitted to; the 12 size seems to match engines of the Twin Wasp size, but this carb looks like it would be for something of a lot less horsepower. I’d been toying with the idea that it was an earlier version carb for a Pratt & Whitney [i.e. before the pressure carbs came in] – but that’s just my latest wild guess and perhaps that can be ruled out now as you say that almost all Wasps used the Y. Hmm.
Thanks again for all your help 🙂

CarolineW,
The carb you have is not a “Y” series carb. First: NA = Stromberg, 2nd: Y=double throat w/ floats in front of and behind the throats (venturies). R=single throat. 3rd: Almost all of the Wasp engines used NA Y(letter design.) carbs.
The Wasp and Hornets used the same carbs with different jets. Ex: NA YC. The Wasp Jr.’s usually used single throat carbs (NA R(letter)). The number was used as a S.A.E. standard for the base and the venturi.
I have the SAE info if you can give me the dimensions between the mounting holes as well as the size of the throat.
So to clarify; NA-Y8C = Stromberg, double throat, SAE size 8 venturi and mounting flange, and “C” = the real minutia of the jets and horsepower etc designed for that particular installation.
Cheers,
Ed

Hi ericmunk, thank you – that’s sounding very promising. Especially so as now I’ve found several records of Lockheed Hudsons crashing or being wrecked up here during the War.
Thank you 🙂

Daniel Craig,
Ha ha, thank you! 🙂
It’s very interesting you should say that. I do indeed find that the most intriguing part of my job is finding the story behind the artefacts; the how and why they got there and what they can actually tell us; the “so what” part.
And I would really like to see a miffed Paraolympian running down Putin and giving him a damn good flogging. It really is beyond time someone did do something.
I do like the idea of The Carby Has Risen, and for a reason 🙂 Though I think I shall be stuck up here for a while yet, I certainly do like the idea of taking some time out to do some interesting aviation arch projects down there. Honestly, do please contact me [crwilby@hotmail.com] if you have any thoughts of how I could contribute.
🙂

Hiya Bager1968, thank you for your reply. That definitely sounds like a good possibility looking into aircraft fleeing the Japanese invasion and moving south; three of the USN Cats that were wrecked here actually ended up in Darwin Harbour for that very reason! I’ll see what I can find. The earlier dates you mention re. the Douglas 0-46 also sound interesting – I have a feeling this carb might have been an early version component.
Thanks again for your help 🙂

Hi Avro Avian, thank you. I hadn’t even heard of the R-1690 Hornet. Definitely sounds like a good candidate – I’ll see what I can hunt down on them. Would be neat if that one were still hanging in that workshop! 🙂

R-1690 Hornet

Also fitted to several variants of the Lockheed Hudson, Lodestar and Super Elektra, all of which have a strong tie to the area through the RAAF, RAF, USAAF, USN, KNIL and/or KNILM.

It wasn’t Hughes Trading Ed (I used to visit there as well :)). IIRC it was further in towards the city on the right hand side. Looked like an old automotive workshop. I’ve killed a lot of brain cells in the meantime, so that’s about all I remember…

[QUOTEI do remember seeing one hanging on a wall in a workshop on Sydney Road, Brunswick, Victoria, in the early ’80s. I don’t know what happened to it, but I suspect it is still kicking (hanging?) around somewhere. :)[/QUOTE]

Where on Sydney Rd !? Was this Hughes Trading in Coburg or deep in the shopping strip, which is the longest continuous shopping strip in the southern hemisphere. I know, because one night, under the mystical influence of cheap red wine, I , in company , re enacted the chimney sweep scene from Mary Poppins across the roofs of said shopping strip, until brought down by the law. I feel I know the place.

Welcome to Aeroplane World

[QUOTE but this project has turned me into a bit of an aircraft nerd so I am definitely interested! 🙂
[/QUOTE]

Diver Caroline,
You’re welcome, and welcome to Planet Plane:cool:

All these things in the end are stories about people, who flew what you have uncovered and why. That’s when it becomes really interesting. This month Mr. Putin rolled tanks into the Crimea and I have an odd feeling that not much will be done about it at all. The last time I read about something like this Mr Schickelgruber rolled tanks into Czechoslovakia, and not much was done about it at all. It is easy to criticize the appeasment of the 1930’s, harder to ask what you are going to do about Mr Putin today.

A piece of American carburetor is brought out from the deep thousands of miles from where it was manufactured. Why was it there ? The more you dig the more threads appear that link you to the present. So far, in the Security Council, the Chinese delegate looks very uncomfortable about Mr Putin. Conflicted emotions. It won’t take long to twig that the way to take Taiwan is just to roll amphibious landing craft onto a Taiwanese beach. Should have done it during the Olympics, too. Classy. What we really need is a miffed Paraolympian to run down Mr Putin in their wheelchair, give him a flogging for being such dick and vomiting the 20th century back into the 21st.

Aircraft I certainly find to be amazing mechanisms, products of astonishing ingenuity. Historical military aircraft are also levers into those parts of the human condition that are most interesting, sometimes simply for tragedy. Find the story behind the carburetor and you will find a very interesting story, no doubt.

These kinds of deep and meaningful conversations you will find in Melbourne, Diver Caroline, instead of hanging around dudes in Darwin whose idea of fun is to run around in undies chasing cane toads with golf clubs. Now that you have the plane bug you can pioneer Aviation archaeology in Victoria. No one is doing anything about it, the water is clear, the things that bite do so once and for ever and there are a lot of projects that would benefit from a trained approach. THIS IS WHY THE CARBY HAS RISEN !

The United States Douglas O-46 (produced 1936-37) was an observation aircraft used by the United States Army Air Corps and the Philippine Army Air Corps. It used the Pratt & Whitney R-1535-7.

At least 11 O-46s saw overseas duty; two were destroyed in the Japanese raid on Clark Field in the Philippines on 8 December 1941. The type was relegated to training and utility roles in late 1942.

So an aircraft fleeing the Japanese invasion of the Philippines may well have reached Darwin.

One other possible engine candidate for this mystery carb could be the Pratt and Whitney R-1690 Hornet. I don’t have a picture or any publications to help, but I do know we had Hornets out here. Off the top of my head, I think the Junkers W34 and possibly the Junkers G31 had them fitted. No doubt other aircraft used them here as well, but not a common engine. I do remember seeing one hanging on a wall in a workshop on Sydney Road, Brunswick, Victoria, in the early ’80s. I don’t know what happened to it, but I suspect it is still kicking (hanging?) around somewhere. 🙂

Hi ericmunk, thanks so much for your reply.
Awesome – I’m looking through records of NT crashes at the moment so I’ll keep a look out for any Douglas O-46.
Thanks heaps 🙂

Daniel Craig,
I’m sorry for my long delay in responding – I’ve been out in field and away from internet access.
Thank you so very much for all your time and for looking into this further. That’s awesome information!
After your response the other day I started tracking down records of crashes in the NT and now comparing that with your identification of PD9 carb and corresponding engine capacities, I’ve found one land crash so far that had a P&W Junior Wasp – but it was an R-985 [Lockheed 12 / C-40]. Nothing on any Vindicators yet, but I certainly feel its getting closer and I’ve still got records to look through. You’re right in that there were so many crashes up here – nice range to chose from! I’ve also only been looking at WWII crashes at the moment, so I’ll push it back further and see if there were any earlier in the 30s. Thank you so much – it’s great to have something to anchor the research on.
And thank you again for your wonderful insights into the likely crashing event sequence with regards to the melting & corrosion of the aluminium, and dumping activities. I can’t describe how helpful that is. Whilst some aircraft parts we’ve found were in discrete piles, several others were scattered amongst ferrous debris – luckily for us as that was one of the main reasons we actually found a lot of the aircraft material. So the signs of rust suggesting proximity to other discarded objects that you identified on this carb certainly corresponds to the latter pattern and really helps with interpretation.
The wade out to the Cats really is rather nasty [!] and a pub visit is pretty much obligatory afterwards I believe 🙂 Perhaps even before and after…!
I do miss decent coffee. And I seriously would love to be involved in searches for wrecks in Port Philip. I’ve been doing archaeology for years but only working on aircraft maritime wrecks for the last two years – so I don’t know how much I’d be able to contribute and as you know, my knowledge is quite limited – but this project has turned me into a bit of an aircraft nerd so I am definitely interested! 🙂
Thanks again so much for all your help 🙂

The R-1535 was also fitted to the Douglas O-46, which may have been associated with the area through the USAAF.

PD 9

Hi Pete, ah yes, it can’t be a “S” 🙂 Sorry, I’m a bit slow on replying – we’ve been having power issues in Darwin today!
You’re bang on; the Venturi size is 3 1/8″. Am I right in understanding now that that’s what the “12” signifies in the model code?
I’ve wondered too if it is instead an automotive or marine engine part. My gut feeling was that it was aircraft, largely due to size and that it seemed too pretty [for want of a better word] to be anything else – looking at the use of safety wire to secure bolts etc. We have actually found some auto parts – including some Australian version universal carrier parts – dumped nearby, but they used plain old Ford V8 engines. It could very possibly a larger vehicle or tank though; I don’t know much about tank engines – I’ll definitely look into that. Thank you 🙂

Diver Caroline,

With great assistance from enginehistory.org, it looks like a PD9 Bendix Stromberg carburettor design, based on the venturi size, which should be 3 and 3/16 inches, suitable for engines of 900 – 1900 sq inch capacity. Some photos attached of the design ( B&W for Wright R 1300 engine and colour cutaway for Pratt and Whitney R1830, although this is a larger capacity carb, it illustrates the position on the engine and 45 degree flange connection)

The PD 9 design is listed as suitable for T-28 Trojan (Vietnam War era) a Sikorsky helicopter (Korean War era) and a Chance Vought SB2U Vindicator, a late 30’s carrier based aircraft that fought at the Battle of Midway in early 1942, but was withdrawn from service soon after.

The SB2U had a Pratt & Whitney Junior Wasp or R1535 engine, a precursor to the far more common P&W Twin Wasp or R1830 engine, which was in everything. So it looks like some sort of carburettor associated with the Wasp engine family.

I have found references to a Bendix NA 8 & NA 9 carb used in the common R 1340 Single Wasp engine, so the NA 12 implies something larger than the Single Wasp.
I have found references to a PD 12 (larger venturi) used on Twin Wasp, so the PD 9 is smaller than 1830 but larger than 1340, ergo 1535.

As an unusual and obsolete carrier based fighter there may have been one or two still on charge with the US Navy during the Guadalcanal and Coral Sea battles, perhaps as a communications hack. It would be interesting to see if there are any records of a crash of a Vindicator flying off a visiting carrier onto a Darwin aerodrome. Given the way the carby has been ripped from its mounting on the engine, it suggests a tumbling engine, leading to the thought of a fairly catastrophic landing accident followed by a fire that was sufficient to melt the aluminium while the carby was upside down, dripping molten metal like a candle dripping wax. I don’t think this was a crash into water. Maybe this was an old plane siting in a corner that was just burnt and crushed by a recovery crew with nothing much to do. The proximity of other dumped material to the find suggests a pattern of dumping in the area, again suggesting a ‘clean up’ disposed off in a habitual way.

The rust on the carby suggests it was mixed with ferrous material, and the aluminium acted as a cathode to the sacrificial anode of ferrous material over time, whether tubular farmework of the engine mount or other material. It would be difficult for a magnetometer to get a clear signal from small, dispersed oxidised tube remnants.

I tried to wade out to the Catalinas last century, sunk nearly up to my armpits in the mud, and only just made it back to the pub.:very_drunk:
You need to leave that land of mud, cyclones and thongs and come back to the great white sharks of the south and dive on some real aeroplanes. We need smart cookies like you to kick some goals in aviation archaeology, find some MIAs in Port Phillip and be able to drink a decent coffee. We even have a magnetometer for you.

Hi Pete, ah yes, it can’t be a “S” 🙂 Sorry, I’m a bit slow on replying – we’ve been having power issues in Darwin today!
You’re bang on; the Venturi size is 3 1/8″. Am I right in understanding now that that’s what the “12” signifies in the model code?
I’ve wondered too if it is instead an automotive or marine engine part. My gut feeling was that it was aircraft, largely due to size and that it seemed too pretty [for want of a better word] to be anything else – looking at the use of safety wire to secure bolts etc. We have actually found some auto parts – including some Australian version universal carrier parts – dumped nearby, but they used plain old Ford V8 engines. It could very possibly a larger vehicle or tank though; I don’t know much about tank engines – I’ll definitely look into that. Thank you 🙂

Yes, the -12 does refer to the Venturi size.
It is probably from a reasonably big engine, 30 litres or so.
It wasn’t used on any of the mainstream WW2 aero engines, but I think it probably pre dates WW2.

Pete

Daniel Craig,
Damn! I could use you in the field up here!
I noticed the melting and thought it was in a position where carbs usually burn, but I don’t know anywhere near enough to get so much information & insight out of it as you have. That’s amazing. Thank you so much. I have to ask – do you think there’s any way that such damage / burning could have occurred with an aircraft crash at sea? One of the biggest questions [other than what the hell is it], is determining whether it could be part of an in situ site or just part of the scatter of post-war discarded debris. Though the only recorded missing wrecks in the harbour are the Kittyhawk and a A6M Zero, you never know.
I’ll start chasing up records of what aircraft were in use at the airbases up here and whether there were recorded crashes. Thank you very much for that suggestion 🙂
So you’ve experienced the wonderful Darwin mud? I’ve had to do that awful wade out to Cat 1 too! When were you last up here looking at Cats? The 6th missing one [USN] was finally found up here a couple of years ago and from what I’ve seen its in almost perfect condition.
The problem with the site where the carb was found is that it is in the middle of an area of sand waves; we’ve done magnetometer and gradiometer searches across the area a few times but with not a lot of success. This carb was a chance find that just popped up and getting access back out there is tricky – we’re doing all this as clearance work in association with the dredging for new shipping channels – so very tight timetables and access restrictions.
I’m actually from Melbourne – though I haven’t had a chance to dive down there yet & working on some unsurveyed aircraft wrecks sounds awesome! Think I’ll be wearing a cardy too though when I do get back down there; especially after spending so much time up here….
Thanks again for all your help 🙂