Reggiane Re 2004

[archipeppe]

Despite its number Reggiane Re 2004 was developed after the Re 2005 "Sagittario", effectively the Re 2004 could be easily regarded as a Re 2005's variant with a different engine, instead of the actual DB-605 the new aircraft should be propelled by an Italian engine the Isotta Fraschini Zeta R.C. 24/60 with 24 cylinders at X shape, air cooled with a power of 1250 CV.

The Ministero dell'Aeronautica (Ministry of Air War) immediately issued an order to produce a couple of prototypes of such aircraft, and the Isotta Fraschini provided a mock-up of its engine in order to realize the nacelle to fit with the new nose for the Re 2004.

This mock-up was actually used in the central nacelle of a Savoia Marchetti SM-79 in order to realize the nacelle.
The Ministero ordered two Re 2004 prototypes and 4 pre-production aircrafts:

- sn. 90377 and 90390 for two RE 2004 prototypes;
- sn. 90454 for four RE 2004 of pre-series;

To Eng. Longhi never liked this new machine, instead he always preferred the Re 2005 correctly regarding it as a real winner.

Due to production problems, due to the particular cooling system, Isotta Fraschini was never able to provide its engines to Reggiane, and the Armistice arrived (8 September 1943) with any Re 2004 in flight condition.

It is not clear if some parts of the Re 2004 was ever manufactured, or it was incorporated in the actual production of the Re 2005.

Source: http://www.alireggiane.com/aerei-f2/re-2004-t327.htm

 

[Justo Miranda]

Unknown to me...

 

[Nick Sumner]

Many thanks for this!

The drawing of the Re2004 has an intake above the engine suggesting a down draught carburetter, but the photos on the linked website of the SM79 test installation show an intake beneath the engine suggesting an up draft carburetter. Why the difference?

 

[archipeppe]

Many thanks for this!

The drawing of the Re2004 has an intake above the engine suggesting a down draught carburetter, but the photos on the linked website of the SM79 test installation show an intake beneath the engine suggesting an up draft carburetter. Why the difference?

Nice question.

The difference is given by the fact that the drawings are a reconstruction of the nacelle's appearance made post-war beacuse production drawings were lost shortly after armistice.

Probably the SM-79 trials suggested to do that or not, but it is mine hypotesis....

 

[elmayerle]

I've heard of this and seen a little in some old books (if they date back to the early 1970s, they classify as "old" to me since I was incollege then, when I purchased them - still have them, somewhere). I'd love to have enough info to do a conversion on a Re.2005 or fit the same engine to Fiat or Macchi designs.

 

[archipeppe]

I've heard of this and seen a little in some old books (if they date back to the early 1970s, they classify as "old" to me since I was incollege then, when I purchased them - still have them, somewhere). I'd love to have enough info to do a conversion on a Re.2005 or fit the same engine to Fiat or Macchi designs.

As far I know the only other fighter aircraft that seriously took in consideration the use of I.F. Zeta was the outsider Caproni-Vizzola F6MZ, a descendant of the F5. Only two aircrafts of the type were ordered but only one was completed and flown shortly before the Armistice, it was the lonely aircraft to go in air with the Zeta engine...

 

[Skybolt]

... mmm, and the SM-94.... and the SAI-404 and 504. For a while the Zeta was even intended for the SM-91. Apparently Regia Aeronautica wanted to pursue a double path with fighters: a quick one, based on license-built German engines, and a completely indigenous one, using Italian engines (the Zeta was paramount, but the "real" challengers would have to be the Alfa 1101 and the Fiat A.44, with the A-40 as a back up, the former an H and the latter an X) and airframes from secondary builders.
By the way, apparently the real problem with the Zeta was in the coupling of the cylinder banks to the main shaft and oil circulation. The cylinder-piston assemblage was of a proven type, since the Zeta was made by two I.F. Gamma coupled. I.F. had the same problem with the Sigma.

 

[robunos]

By the way, apparently the real problem with the Zeta was in the coupling of the cylinder banks to the main shaft and oil circulation. The cylinder-piston assemblage was of a proven type, since the Zeta was made by two I.F. Gamma coupled. I.F. had the same problem with the Sigma.

sounds a lot like Rolls-Royce and the Vulture...


cheers,
Robin.

 

[archipeppe]

... mmm, and the SM-94.... and the SAI-404 and 504. For a while the Zeta was even intended for the SM-91. Apparently Regia Aeronautica wanted to pursue a double path with fighters: a quick one, based on license-built German engines, and a completely indigenous one, using Italian engines (the Zeta was paramount, but the "real" challengers would have to be the Alfa 1101 and the Fiat A.44, with the A-40 as a back up, the former an H and the latter an X) and airframes from secondary builders.
By the way, apparently the real problem with the Zeta was in the coupling of the cylinder banks to the main shaft and oil circulation. The cylinder-piston assemblage was of a proven type, since the Zeta was made by two I.F. Gamma coupled. I.F. had the same problem with the Sigma.

Thanks a lot Skybolt, I didn't know that also the SAI fighters and the SM-91/94 was meant to utilize the Isotta Fraschini's.

 

[Skybolt]

.. ehm, Sm-94 is a typo, I meant SM-96 II.... The 94 had Deltas.

 

[Nick Sumner]

...the Fiat A.44, with the A-40 as a back up, the former an H and the latter an X)

Skybolt, is there much more information anywhere about these Fiat engines?

 

[Skybolt]

The sole info known on the A-40 come from the Dante Giacosa's autobiography (the great car designer for FIAT from 1935 to 1970), a little garbled in this section (he has the dates postponed for unknown reason of a full year). Of the engine itself only a two views survive. Of the a-44 little more is known. The two are linked, since the A-40 was started as a fall-back alternative in case of the failure of the A-44. I'll cover these two engines in ISP. What I can say here is that the A-44 was an H using the same cylinder banks (8 cylinder per banks) of the A-38, delivering 2400 HP with 32 cylinders. The A-40 was more "modest" and used six banks cylinders in a more efficient X configuration, for a total of 1900 HP with 24 cylinders. Both were intended as a national alternative of the previewed successor of the DB-603, that Italy already agreed to license produce in early 1943. The A-44 was "used" in the Rosatelli's projects CR-44 and BR-44 from 1941 and considered in at least one of the various fuselage mounted engine heavy fighters Italy was developing in the late war. It was an heavy engine, 1500 Kilos, with a big front section. I am not aware of perspective uses for the A-40. Giacosa says that at the armistice an prototype was on the trialbank. Apparently Regia funded for 1943 the A-44 only, so the A-40 was still pursued as a private venture (a logical decision, since it was intended as a back-up project).
Just one more thing: if someone of you have Aerofan n.100, you'll find my article on the CR-44 stating that the fighter used the A-40 in an evolved version. Just at the time the article was in the press, I discovered the sole surviving drawing of the A-44 and, bingo...

 

[archipeppe]

It's a fact that the Regia Aeronautica had ambitious plan to substitute the old air-cooled radial engines with more powerful air-cooled new generation national engines. It is also a fact that the national industries (Isotta Fraschini, FIAT and Alfa Romeo) for various reasons failed to achieve such goal, leaving only the german liquid-cooled engines (DB-601 and 605) to power the latest generation of fighters.

Too bad....

 

[Maveric]

... mmm, and the SM-94.... and the SAI-404 and 504. For a while the Zeta was even intended for the SM-91. Apparently Regia Aeronautica wanted to pursue a double path with fighters: a quick one, based on license-built German engines, and a completely indigenous one, using Italian engines (the Zeta was paramount, but the "real" challengers would have to be the Alfa 1101 and the Fiat A.44, with the A-40 as a back up, the former an H and the latter an X) and airframes from secondary builders.
By the way, apparently the real problem with the Zeta was in the coupling of the cylinder banks to the main shaft and oil circulation. The cylinder-piston assemblage was of a proven type, since the Zeta was made by two I.F. Gamma coupled. I.F. had the same problem with the Sigma.

Hi Skybolt,
do you have more info about the SAI-504? Its unknown to me ???

Thanks Maveric

 

[Skybolt]

Mav, you'll have to wait ISP for more circumstantial info, anyway it was the pure fighter version of the 404, with a slightly enlarged wing area and less weight. The 404 was, in fact, a fighter-bomber, something in the lines of the Typhoon or the specialized versions of the FW-190. And this I think is news.

Peppe, you are actually conflating two moments: the air-cooled drive was linked to radials and is from 1936-38, when Regia push was on air-cooled RADIALS, normally working on evolutions of license-built type. For example, the Alfa 126 was an evolution of the Bristol Pegasus and Jupiter. The Alfa 135 (presented in prototype form in Milan Air Fair in 1937 !!!!, Gone in limited production in 1943 !!!!! :'( ) was two Bristol Mercuries coupled (the never built 138 was in turn two 126 coupled). Other license built radial types were form G-R and P&W (Piaggio and Fiat). Only IF persevered in evolving the air-cooled inline (following the big Asso success), with the various Beta, Gamma, Delta, and later Zeta. When in 1939, the inline liquid-cooled returned in favour, a couple of projects were initiated: IF L-121; FIAT A-38 notably. Anticipating problems, Regia acquired the license for the DB-601 and started inquiring on the then in development DB-604. The next round of inline engine projects came in 1941, when FIAT started the A-44 (then A-42) and the A-40, Reggiane the 103-105 M engines, Alfa the 1101.
The Zeta and Delta were "used" in mid-to-late war in secondary or wooden projects. Invariably, when you consider "front line" planes in that period, both built and projected, they used DBs or Piaggio and Alfa radials. Only from 1944 (I suspect, late-1944) on, new front line projects would have to be powered by all-Italian engines, flanked by the license built DB-603. Or so was the plan in Spring 1943.

 

[archipeppe]

Many thanks Skybolt, now you makes clearer a lot things!!

 

[Nick Sumner]

Skybolt,

ISP = Italian Secret Projects?

;D ;D ;D

Do you have a publication date?

 

[Skybolt]

Yep. Not earlier than summer 2011, I guess.

 

[archipeppe]

Yep. Not earlier than summer 2011, I guess.

We're all waiting for that.....

 

[Nick Sumner]

Yep. Not earlier than summer 2011, I guess.

We're all waiting for that.....

Indeed we are!

;D ;D ;D

 

[archipeppe]

A rare shot of the Caproni-Vizzola F-6MZ.....

 

[Retired In Kalifornia]

Photo Samples Of My LF Models Reggiane Re.2004 Kit Bash...

All resin LF Models Kit 7281 Caproni Vizzola F.6Z Isotta Fraschini Zeta engine section grafted on nosed sawed-off Kit 7241 Reggiane Re.2005 "VDM" fuselage, join near perfectly aligned much to my eternal delight, no other modifications necessary other than spot sanding over & around the join: