Any additional information about the Svenska Flygmotor Mx project?

[Hardrada55]

Here's what I have so far.

"Svenska Flygmotor started the Mx project during the summer 1941, intended for the Jx and Bx fighters, to be ready in 1947."

I wonder what the Jx and Bx aircraft were?

"Its configuration would have been two V-12s in an X-configuration. Diameter 1.28 m, 54 litre stroke volume, injection pump, overhead cams, turbo compressor, power up to 2500 hp."

Half of 54 Liters is about 1650 ci. Was this project two Merlins in an X configuration, like the Vulture was two Peregrines in the X configuration? In effect, similar to a 3300ci Vulture? I think the Ford V-12 was 1650 ci with double overhead cams, so it could be an X version of the Ford engine.

 

[Apophenia]

Mx Project cylinder tests were conducted late 1943. In late 1944, a single 6-cylinder bank ready for testing. The Mx Project closed down in 1945.

I suspect that the "Jx and Bx fighters" were actually future fighter and bomber projects - B for Bombflygplan, J for Jaktflygplan. These projects were probably at an early definition phase ... or the Flygvapnet would have assigned them P for Provflygplan designations.

 

[Hardrada55]

Found this information online. "...at the end of 1941, was commissioned to develop a 24-cylinder air-cooled piston engine of 2 200 hp called Mx. It was built as a six-cylinder star engine in four underlying wreaths." Sounds like an engine similar to the AS Wolfhound.

 

[Kevin Renner]

Found this information online. "...at the end of 1941, was commissioned to develop a 24-cylinder air-cooled piston engine of 2 200 hp called Mx. It was built as a six-cylinder star engine in four underlying wreaths." Sounds like an engine similar to the AS Wolfhound.

Or an air cooled Jump 222

 

[Apophenia]

Possibly of interest ...

Kritiska År: Formativa moment för den svenska flygplansindustrin 1944–1951 by Kristoffer Strandqvist, 2008
https://www.aef.se/Kopierade_dokument/Kritiska_ar.pdf (see pp 106-108)

(Para-phrased) Authorization came from Flygförvaltningens in November 1941 for SFA to develop an aero-engine producing 2,200 hp (with further development potential). Three configurations were examined - a liquid-cooled dubbel DB-motor; an air-cooled H-engine (dubbel boxermotor); and an air-cooled radial. At the end of February 1943, the radial layout was selected.

Later, it seems, a conclusion is drawn that Jx could be built with licensed DB605s without too much disruption of the Swedish aero-engine industry (ie: the DB605 would fill the gap until new jet engines appeared). Development work continued until 1945 for its own sake, rather than to result in a finished engine ...

The mention of an H-engine layout is interesting. Possible the same type connected with early incarnations of the J27?

Going back to the Jx and Bx ... on pg.96 there is mention of "projekteringsutkast för 1- och 2-motorigt fpl för MX" or single- or twin-engine aircraft projects for the Mx engine.

BTW, what was the Flygplan 24 project?

 

[Hardrada55]

Perhaps this. https://sv.m.wikipedia.org/wiki/Saab_24

 

[Hardrada55]

What can you tell me about the early incarnations of the J27? How is the "H" engine connected?

 

[blockhaj]

Ok so ive just gone through the thread a bit ruff but basically lets starts with the Jx and Bx of planes. As previously mentioned these where future fighter and bomber planes. J for Jakt = fighter and B for Bombare = bomber. X is just for experimental.

Now to the engine, it basically started with that Sweden wasn't able to acquire any type of engine for future planes of the Swedish air force.

In 1939 Sweden wanted the Bristol Taurus engine for the future planes such as the Saab L-19 and ASJA L-11. When Brittain entered WW2 all of the engines where reserved for the British air force and Sweden wasn't able to buy any.

Sweden then turned to s for the US to buy the second best option which was the Twin-wasp. Sweden ordered several hundred t&w engines but the US embargo on Sweden in 1940 made it so all the engines where taken over by the US. So at this point there where basically only two options left and that was to either design our own engine or get a deal with the Germans for any of their powerful engines. Sweden had bought and ordered a lot of German military material during the 30's but due to the War Germany cancelled a lot of the orders such as 18 Do 215's intended for the SAF.

Due to this an ingenious design was preferred as the Germans couldnt be trusted and the SAF was tired of constantly loosing money on material that wouldnt be delivered. SFA (Svenska Flygmotor AB "Swedish plane engines AB") was ordered to make a new engine with 2000 hp. The project got the name Mx (most likely for Motor experiment or something similar). Due to reliability fear and experience by the service men a radial engine was preferred by the SAF but SFA wanted to make an inline engine. They choose to make a hybrid between and X-engine and an H-engine. The cylinders would be set in two V-12 rows on top of each other with the bottom one being inverted (very similar to a lot of X-engines), but each V had its own crank converter (or whatever the term is) like an H-engine. This would possibly allow for an engine cannon but nothing came out of that idea.

Before SFA could really start developing they where ordered to pirate copy the Twin wasp engine as Sweden desperately needed an engine yesterday. Due to the pirate copying the Mx projekt was put on hold. Due to the rapid development during the war when the project rolled again the specification had changed and the engine should now have 2200 hp.

Not to long after this SFA was tasked with redesigning the DB 605B for Swedish production which took way longer as expected as over 5000 changes had to be made. After this was done the war was basically over but the specifications had changed yet again and Sweden now had a project for the engine, the Saab 27. The new specifications said 2500 hp. But SFA had basically stopped development either way as they had been working on a jet engine since the late 30's and built it in 1944. Saab soon cancelled the Saab 27 project and that was the final spike in the coffin for the SFA Mx.

Some mentions of the engine for passenger planes is mentioned after this such as the Saab scania but an improved version of the pirated twin-wasp was seen as more practical as this engine was already built and working.

 

[wagnerleung0079]

Not to long after this SFA was tasked with redesigning the DB 605B for Swedish production which took way longer as expected as over 5000 changes had to be made. After this was done the war was basically over but the specifications had changed yet again and Sweden now had a project for the engine, the Saab 27. The new specifications said 2500 hp. But SFA had basically stopped development either way as they had been working on a jet engine since the late 30's and built it in 1944. Saab soon cancelled the Saab 27 project and that was the final spike in the coffin for the SFA Mx.

Would you kindly provide more information regarding the Swedish redesigned DB 605? Thank you.

 

[blockhaj]

Not to long after this SFA was tasked with redesigning the DB 605B for Swedish production which took way longer as expected as over 5000 changes had to be made. After this was done the war was basically over but the specifications had changed yet again and Sweden now had a project for the engine, the Saab 27. The new specifications said 2500 hp. But SFA had basically stopped development either way as they had been working on a jet engine since the late 30's and built it in 1944. Saab soon cancelled the Saab 27 project and that was the final spike in the coffin for the SFA Mx.

Would you kindly provide more information regarding the Swedish redesigned DB 605? Thank you.

Its basically just a DB 605 B (1475 hp) built for peace time, meaning it will not commit suicide after a month.

 

[wagnerleung0079]

Its basically just a DB 605 B (1475 hp) built for peace time, meaning it will not commit suicide after a month.

Sorry for finding out your reply that late. So does it mean Sweden has no actual follow-up R&D program on DB 605 like France did for Jumo 213 or BMW 003?

 

[blockhaj]

Sorry for finding out your reply that late. So does it mean Sweden has no actual follow-up R&D program on DB 605 like France did for Jumo 213 or BMW 003?

No, starting from 1945 all piston engine development seized and all focus shifted to jet engines. The SFA DB 605 had 5000 changes done to it for production which made it suitable for peace time. Swedish engines were prioritized for SAAB 21s, once series A-2 had been built, engines chifted to SAAB 18Bs, as the German engines had started to fail by this time (ca 1947), leading to a requirement that all SAAB 18Bs needed to have at least one Swedish produced DB 605 engine installed for safety reasons.

 

[blockhaj]

No, starting from 1945 all piston engine development seized and all focus shifted to jet engines. The SFA DB 605 had 5000 changes done to it for production which made it suitable for peace time. Swedish engines were prioritized for SAAB 21s, once series A-2 had been built, engines chifted to SAAB 18Bs, as the German engines had started to fail by this time (ca 1947), leading to a requirement that all SAAB 18Bs needed to have at least one Swedish produced DB 605 engine installed for safety reasons.

147 octane fuel was introduced postwar ca 1948, modifications was done by Munktells Mekaniska Verkstad AB as far as i know (1700 hp).