Curtiss Wright V-1800 Super Conqueror

[Hardrada55]

Any information about the Curtiss Wright V-1800 Super Conqueror from the early to mid 1930s?

 

[kmccut]

Specs available at

Curtiss and Wright Specifications

 

[Apophenia]

Is it possible that, like the Allison V-1710-A, the Curtiss-Wright SGV-1800 was originally intended as an airship powerplant?

And does anyone know what the 'Navy Design #115' was?

____________________

Smithsonian NASM
The Curtiss-Wright Corporation Records Finding Aid
https://sirismm.si.edu%2FEADpdfs%2FNASM.XXXX.0067.pdf

Box 89, Folder 37

Report No. 4798, File No. 6.5364. "Two-Place Fighter with Curtiss SGV-1800
Engine. Preliminary Weight Estimate" submitted by the Weight Dept.,
4/14/1932

13 pages

Models covered: Navy Design #115.

____________________

I also note that SGV-1800 specs, drawings, and photographs are listed for NASM's Arthur Nutt Collection:
https://airandspace.si.edu/research/arch/findaids/nutt/nutt_sec_7.html

 

[kmccut]

I have written an article about the SGV-1800. Please see

Wright SGV-1800

 

[Piper106]

Very interesting report on development of the Wright V-1800. Thanks for your efforts into the research needed.

Yes, there were a lot of 'teething' problems with the V-1800 during the initial test runs. However best I recall from reading "Vees for Victory", the Allison V-1710 also seem to be plagued with similar breakdowns during for the first several years of its development. Early running of the Rolls Royce Merlin was "no walk in the park" either.

Likely it was best that Wright did not try to spread their resources over both radials and the V-1800.
Still there seems to be an interesting 'what if' in the V-1800.

 

[Apophenia]

I have written an article about the SGV-1800. Please see
http://www.enginehistory.org/Wright/SGV-1800.shtml

Great stuff! Many thanks for that.

 

[kmccut]

Very interesting report on development of the Wright V-1800. Thanks for your efforts into the research needed.

I would like to have reviewed the Arthur Nutt papers again for more information on this engine. I worked with that collection in 1999 when I was researching my Tornado book, but was focused only on Tornado-related material. I think it would be instructive to review the Nutt papers from a more general perspective.

Yes, there were a lot of 'teething' problems with the V-1800 during the initial test runs. However best I recall from reading "Vees for Victory", the Allison V-1710 also seem to be plagued with similar breakdowns during for the first several years of its development. Early running of the Rolls Royce Merlin was "no walk in the park" either.

All true. My intent was to document some of the major development hurdles the SVG-1800 faced. Having read scores of these engine test reports from many manufacturers, I am amazed at how frequently test engines broke down and at the often trivial causes. One would think a manufacturer would have subjected the engines to private testing rather than to suffer the embarrassment of having them blow up in front of the customer, but no! I suspect the development and type tests were so expensive that manufacturers did minimal private testing, let the governments pay for as much as they would, and saw the public failures as just a part of the process.

Likely it was best that Wright did not try to spread their resources over both radials and the V-1800.
Still there seems to be an interesting 'what if' in the V-1800.

I do not think Wright had a lot of depth to either its engineering or management, and I do not have the impression what it did have was well utilized. In my experience with reading Wright correspondence, proposals and reports, I think Wright management was always more focused on selling the next new thing that on making current products as good as they could be. Wright was reluctant to admit problems, tried to blame obvious problems on others, and was VERY slow to actually fix anything.

In digging through boxes of documents at various archives around the USA, I have formed the opinion that Wright tended to stress flash over substance. Wright correspondence, as compared to that from other aircraft and engine manufacturers, is written on very high quality heavy embossed paper, and Wright proposals/reports are bound in beautiful high-quality gold-embossed covers. However, the correspondence has far more grammar and spelling errors (again, as compared to others), and the reports often lack key information or state it imprecisely, leaving the impression they were not quite finished. For example, in all the material I collected on Wright R-2160 Tornado performance, the manifold pressure at which the engine presumably produced it stated performance is not stated, NOT ONCE!

 

[kmccut]

I have added more information to the SGV-1800 article covering development through June 1934.

 

[Hardrada55]

kmccut - Allison didn't achieve 1000hp with the V-1710 until 1937 and their first results with the Allison don't seem too different from what Curtiss was getting with their V-1800 at about the same time period. In fact 1000hp at 2400rpm for take off may be better than what Allison was achieving in 1934. Do you think the V-1800 have been developed into a good competitor to the V-1710? The Soviets bought the V-1800 then ditched it for the Hispano Suiza 12Y in 1934 after starting production of the V-1800. That doesn't speak to a lot of confidence that they could develop the V-1800. Was there a fundamental flaw with the V-1800 that is easily knowable with the benefit of hindsight? Do you think the Soviets abandoned the V-1800 because they thought that it was too technologically advanced for them to produce and that the HS 12Y was better suited to their technology and manufacturing abilities?

 

[kmccut]

Hardrada55-
All engines require extensive development testing. This was particularly true in the days before computer models. While the V-1710 suffered it own development issues, the difference is that Allison stuck with it and did not expect its customer to pay for it all. Keep in mind that we do not know how long the SVG-1800 ran at 1,000 hp; I would bet not long. It did not have a lot of time at 800 hp. One metric tells the whole story --- 240 hours total time running, with only 100 between 18 September 1932 and 30 July 1934. Let us assume Wright began on 31 December 1931 (probably earlier). That means that at least 942 days elapsed between start of development and 30 July 1934.
It is instructive to examine the Pratt & Whitney R-2800 development timeline:
31 Mar 1937, Day 0 = Design started
3 Jun 1937, Day 64 = Drawings released to experimental shop
13 Sep 1937, Day 166 = First run
18 Nov 1937, Day 232 = First 100 hours running completed
15 Aug 1938, Day 502 = First 1000 hours running completed
1 Jul 1939, Day 822 = Type test completed
12 Jul 1939, Day 833 = First flight
Engineering hours through type test = 325,000 (not a typo, three hundred twenty five THOUSAND hours)
Hours run through type test = 3,300

That is how you develop a dependable engine!

A factor that repeatedly appears when one examines Wright's development programs or response to field problems is its lack of well-equipped experimental machine shop. Wright relied heavily upon outside machine shops, a practice that was time consuming and error prone. It was also a practice that did not integrate lessons learned into corporate knowledge.

Regarding your questions about whether the SGV-1800 could have been perfected or why it was abandoned by the Russians, I do not have enough information to say. To my knowledge, there is no documentation on the Russian experience, and the little information we have from Wright Aeronautical and Air Corps records, combined with the few hours running, does not tell us much.
One flaw I do see is with the crankcase/cylinder block construction. Each cylinder bank was attached to the crankcase with flanges running along the inside and outside of the bank. By contrast, Allison and Rolls-Royce cylinder banks were attached using long studs that went from the crankcase all the way through the cylinder heads. The latter produces a much stiffer construction. Although 60° V-12s have perfect primary and secondary balance, they still induce crankshaft bending loads that must be resolved through the main bearings and ultimately the crankcase. If the crankcase is not stiff it will eventually crack. I would not be surprised to learn of SGV-1800 crankcase cracks and/or main bearing distress had the engine run more.
Another thing I wonder about is the articulated rods. If you calculate the displacement of a 5.625" x 6" V-12 you get 1,789.2 in³, yet the SVG-1800 displacement was 1,822 in³. The 33 in³ difference was due to the longer stroke on the articulated bank. There are also issues with secondary balance, lubrication, and uneven power impulses. The V-1710, Merlin, DB 601 and Jumo 211 all had fork-and-blade connecting rods. There may have been high-powered V-12s with articulated rods of which I am unaware, but the point is that the fork-and-blade construction was a cleaner implementation.

 

[iverson]

The Soviets bought the V-1800 then ditched it for the Hispano Suiza 12Y in 1934 after starting production of the V-1800. That doesn't speak to a lot of confidence that they could develop the V-1800.

In Russian Piston Aero Engines, V. Kotelnikov says that planned Soviet production of the Curtiss Conqueror and Wright V-1950 T-3 Tornado engines was stymied by the Hoover administration's opposition to trade with Bolsheviks. So I suspect that technical problems werenot the issue in that case.

 

[Hardrada55]

What page is that on?

 

[iverson]

What page is that on?

p. 223 of the 2005 edition

 

[Hardrada55]

Thanks, I had a hard time figuring out what Hoover had to do with a sale of a license for the V-1800 to Russia that took place after Roosevelt took office. What Hoover seemingly scotched was licensing of the V-1570.

 

[rinkol]

The Soviets bought the V-1800 then ditched it for the Hispano Suiza 12Y in 1934 after starting production of the V-1800. That doesn't speak to a lot of confidence that they could develop the V-1800.

In Russian Piston Aero Engines, V. Kotelnikov says that planned Soviet production of the Curtiss Conqueror and Wright V-1950 T-3 Tornado engines was stymied by the Hoover administration's opposition to trade with Bolsheviks. So I suspect that technical problems were not the issue in that case.

The Soviets probably had more engine programs than they really had resources; I can see a strong case for going with the 12Y license; HS would have had business and other reasons for making a serious effort whereas the Curtis liquid cooled engine program had clearly peaked earlier.

 

[rinkol]

The Soviets bought the V-1800 then ditched it for the Hispano Suiza 12Y in 1934 after starting production of the V-1800. That doesn't speak to a lot of confidence that they could develop the V-1800.

In Russian Piston Aero Engines, V. Kotelnikov says that planned Soviet production of the Curtiss Conqueror and Wright V-1950 T-3 Tornado engines was stymied by the Hoover administration's opposition to trade with Bolsheviks. So I suspect that technical problems werenot the issue in that case.

The Mikulin AM series engines successfully used articulated rods. On the other hand, RR had significant rod related problems with the Vulture.

I suspect that Wright was putting its best people on the engines that clearly had a significant commercial market (i.e., the air cooled radials) while the military projects, especially those that had uncertain prospects, wound up with the less capable staff. I've seen this sort of thing in my professional experience - given a challenging R&D problem, it is a mistake to expect miracles if the contractor doesn't have or can't see a business case for doing more than the minimum specified under the contractual terms.