Hardrada55

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Does anyone have any more or better information about the Saurer FLB 2000 engine from the 1940s? Some of the information indicates maybe 2 stroke, fuel injection, opposed pistons, rhombic drive?
http://www.saurer-romandie.ch/La%20maison%20Saurer/les%20dates%20et%20faits%20importants.htm
 

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Found this information online and ran it through Google Translate. Still don't know what to make of it. Is this diesel, or gasoline? Apparently they have information on these engines at the Flieger Flab Museum in Dubendorf, which looks like an awesome place. https://www.afc-fliegermuseum.ch/

"In 1935, Saurer prompted a competition for the creation of an aircraft diesel engine by the French aircraft ministry to develop an aircraft diesel. This was the start of an extraordinary, promising development in Arbon, with the aim of producing aircraft engines from 2000 HP. 8 preliminary studies indicated the already existing Junkers flight diesel engine JUMO, in which both pistons moved in the same barrel axis. In the Saurer solution, the running axes of the two pistons formed an acute angle. While Hugo Junkers JUMO's mixture formation was achieved by rotating air movement, the Saurer project created a well-swirled common combustion chamber at top dead center. By adding a second element in the same plane, but mirroring the other side of the crankshaft plane, a rhombic component was created. For the time being, however, tests were only carried out with half a component. It may be said that this test execution was completely sufficient to clarify the combustion process. It was possible to drive 300 hours in diesel mode and with petrol injection without any problems. After evaluating these tests, construction of the FLB-1000 could begin. With the proud final goal of an output of 2000 HP, the construction of a 3-row engine with an output of 1000 HP was started for cost reasons. With the dimensions stroke 2x 170mm and bore 170 mm required to achieve the performance, the advantages of this arrangement should come to light and be proven for the suitability for larger performances. The FLB 1000 was put to the test and if it was suitable, an unexpected stop occurred on this two-stroke engine. Because the former KTA demanded with priority that the Hispano Suiza engine should be brought up to an output of 1250 hp thanks to gasoline injection. Pity! (At that time, the first gasoline injectors flew in DB-601 engines in the Messerschmitt me 109). These new YS2 were installed in the Morane-Saulnier, D3803 and C3604. With the rhomboid motor it can be seen that here too the construction in Arbon had the lead. Had it gone further, outputs of 2200 to 4500 hp would have been possible with 32 and 64 cylinders."
 
This is a low resolution picture from the Flieger Flab museum. On the far right of the line of engines is an example of one of these engines and above it is a diagram showing how the engine functions. The diagram fits with the description in the posting above of "...the Saurer project created a well-swirled common combustion chamber at top dead center".

b48d0e91f6ae1d30511b3f413db2044e.jpg
 
I don't have any info, but if you find some, please share. I find it a little frustrating that there seems to be so little info about the FLB 1000 and FLB 2000 engines out there, and yet, an FLB 1000 exists. Anyone live near Dübendorf? Below is a crop of the same picture but at a higher resolution.

Saurer.JPG
 
Kind of reminds me of the Michel 2 opposed piston diesel but with one bank cut off. And then the two remaining banks on common crankshafts. Looks to be a really large combustion chamber. Definitely ports in the cylinders and forced induction (the blue area") with swirl in the cylinder. There appear to be an injector and either a spark plug or glow plug in the "head". I think it's a 2 stroke as there appear to be no sleeves in the cylinders to open the ports. Diesel or petrol? I'm sure a clearer picture would help. And just what are wires/hoses for. They sure don't look fuel lines or spark plug leads for an aircraft engine. The black housings I think are the intake manifolds.

I've been paying around in my head with an idea for a two stroke with no intake ports. Instead fuel and an oxidizer are injected directly into the cylinder. I'm sure it's not a new idea. Such an engine would only be practical in certain applications. Drag racing or LSR most likely.

I guess I just need to hit the Powerball :rolleyes:
 
Kevin,

of course it is a 2-stroke with forced induction because here you cannot realize crankcase induction (besides - sleeve valve 2-strokes are possible as well - look at the RR Crecy and other british concepts of the late 1940s). The "wires" are lines that symbolize the intake and exhaust gas flow; the unburned air is the blue area, so the grey area is the exhaust gas flow. It seems to be a well balanced design from the view of mass compensation but with a large combustion area which somewhat reduces combustion efficiency.

And yes, there are numerous injection concepts in engine history where fuel is injected together with air as oxidizer.
 
Kolben-Flugmotoren by Hans Giger mentions the FLB, but has little extra information; it does say development started 1939, but otherwise has only the already mentioned above information or less.
I've only just heard about this Saurer diesel aircraft engine from that source myself, despite having researched diesel aircraft engines for years :( Am blown away the development engine still exists!
 
it is a 2-stroke with forced induction because here you cannot realize crankcase induction (besides - sleeve valve 2-strokes are possible as well - look at the RR Crecy and other british concepts of the late 1940s).

Yes, the Crecy appears to be a striking parallel to the FLB 1000/2000 in several ways; conceived as a two-stroke Diesel, later being converted to run on petrol with fuel injection (Diesels always rely on injection, of course), and never making it into production. But the Crecy had conventional single-piston cylinders. By the way, Jumo was Junkers' wholly-owned engine subsidiary - all Junkers engines were branded Jumo, right through to the jets. The 20x and 22x series were opposed-piston Diesels, I think all two-strokes, while its 21x series were conventional single-piston four-stroke arrangements running on petrol. Saurer bent the two-ended cylinder into a V shape.

The big advantage of the two-stroke is its theoretical doubling of output power, since every cylinder fires twice as often. The scavenging of exhaust gases is critical to the success of this strategy, both to maintain full power and to keep the valves from overheating. To this end, some kind of through-flow within the cylinder is essential; the Crecy drew air in at the bottom and exhausted it at the top, while the Saurer drew it in on one leg of the kinked cylinder and exhausted it on the other.



The Saurer YS-2 and YS-3 were developed versions of the Hispano-Suiza HS77 12Y51 (also known as the HS51-12Y), with increased output.

EKW license-built the Morane-Saulner 450 as the C-36 series, re-engining a small batch with the 1,245 hp YS-2 as the C-3604. Today, D-FEKW is a C-3603 restored as an airworthy C-3604. (See Aeroplane, Aug 2021, p.10.) Unfortunately the restoration involved re-engining with a Merlin as its physical size and power rating are similar to the Saurer (which one might suggest says a lot for the Saurer and, potentially, also the Crecy).

Doflug (Dornier's Swiss branch) similarly licensed the MS.406 as the D-38 series. Variants included around 12 D-3802 with the YS-2, followed by development of the D-3803 with the improved YS-3.



There must be more about the FLB / YS series of engines out there somewhere, probably written in Schwitzerdeutsch or French.

[much updated to correct errors and add stuff]
 
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People able to read German may be interested in the following...

 
The following may perhaps be of interest, once put through Google Translate.

 
I updated my previous post, as I was muddling up two different aircraft projects and not quite explaining the two-stroke wrinkles right. Sorry, folks.
 
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