Italian copies of the DB 601
- Thread starter Sagittario64
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teiresiasx
Airman
- 11
- Nov 4, 2009
Yes.
According to Ali d'Italia n. 2, Aer.Macchi C.202, pag. 4, "the MC.202 was initially equipped with German-built DB.601A-1 engines which, when Alfa Romeo completed its new factory in Pomigliano d'Arco (Naples), were later replaced by the Italian-built version called R.A. 1000RC.41" (it is interesting to note that it appears that German-built engines of M.C. 202 were A-1 and not Aa, but I know other sources tell a different story).
The pilot's notes of M.C. 202 (draft 1941, pag. 129) had a chapter called "Norme per l'impiego dei motori D.B. 601 od R.A. 1000" (i.e. "Instructions for the use of D.B. 601 or R.A. 1000 engines"), the chapter was no longer present in the pilot's notes of M.C. 202 C.A. 670/2 of 1942. Moreover in November 1941 an apparently provisional typescript was published under the title "Norme per l'impiego dei motori D.B. 601 ed R.A. 1000 sui velivoli M.C. 202 ed RE.2001" (i.e. "Instruction for the use of D.B. 601 and R.A.1000 engines on the M.C. 202 and RE.2001 airplane"). This is to prove that both German- and Italian-built engines coexisted, at least in 1941. Incidentally, the typescript explained also that regardless of the engine (D.B. or A.R.) there was only one difference between the rating of the M.C. 202 with Piaggio propeller (whose climbing was allowed at 2,400 rpm and 1,20-1,23 ata for 10') and the RE.2001 with the better Alfa Romeo propeller (whose climbing was allowed at 2,300 rpm and 1,27 ata for 10').
It must be also noted that there were two names for the licence-built DB:
the R.A. 1000 RC.41.I (which means full throttle height at 4,100 m) with a maximum power of 1,175 HP at t.o. (2,500 rpm, 1.45 ata) for 1', 1,100 HP at 3,700 m for 5' and 1,050 HP at 4,100 m for 30', reduction rate 0.643:1 (data from page 11 of "Motore R.A. 1000 R.C. 41.I, Caratteristiche, Uso, Manutenzione", Alfa Romeo, publication n. 4114, July 1941, 1st reprint January 1942); according to the pilot's notes of RE. 2001 (C.A. 627, 1942, page 113) the reduction rate was 0.645:1;
the R.A. 1000 RC.44.I.a (which means full throttle heigh at 4,400 m) with same rating as above but reduction rate of 0.646:1 (data from page 1 of "Motore R.A. 1000 R.C. 44.I.a., Caratteristiche e descrizione", Alfa Romeo, no date [it looks like a draft]); another example of the same draft is dated 1941 and contains a table with the power curves: take off is again 1,175 HP at 2,500 rpm at 1.45 ata; full throttle height is set around 4,100 m and not 4,400.
I therefore suggest that (unless there was a misunderstanding with the German supplier) the R.A. 1000 RC.41.I was a DB.601Aa, whilst the R.A. 1000 RC.44.I.a was a DB.601A-1 (the "a" means "alta quota", i.e. "high altitude")
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al49
Tech Sergeant
Very good information, well done!
Alberto
Alberto
- Thread starter
- #45
Sagittario64
Airman 1st Class
Yes i see the differences and similarities now, thanks for shedding light on wwii italian aircraft engines, of which i think is one of the most obscure topics of wwii aviation. and on a sidenote, how did the italian engines fare in service life? even with sand filters, i imagine the constant drastic changes between scorching day and freezing nights in the desert would have caused many problems for the already strained Regia Aeronautica C.202 engines. i cant imagine the italians could keep up a steady stream of replacement engines, and that they might have had to resort to the east african campaign italian tactic of sending the aircraft with the engine they carried and only one replacement engine(after both engines are worn out they are technically permanently unserviceable until new shipments arrive).
It is very interesting info. I've read it copied for myself. Recently I thought why japans started production of DB-601A engine with t.o.power 1100-1200 h.p. in 1940 while germans already prodused DB-601E/F version with t.o.power 1350 h.p. Why japans did not begin directly from it?
But you do not mention any source of this info!? Could you tell where is it from?
on issuu is available a manual, "Norme per i motoristi addetti all'assistenza", of R.A. 1000 R.C. 41 I. edition november 1942
from page 35th of manual (not of pdf)
max power 1' 2400 rpm 1.4-1.45 ata
max power 5' 2400 rpm 1.3-1.35 ata
max power 10' 2400 rpm 1.2-1.23 ata (for C.202 fighters) 2300 rpm 1.27 ata (for Re.2001 fighters)
from page 35th of manual (not of pdf)
max power 1' 2400 rpm 1.4-1.45 ata
max power 5' 2400 rpm 1.3-1.35 ata
max power 10' 2400 rpm 1.2-1.23 ata (for C.202 fighters) 2300 rpm 1.27 ata (for Re.2001 fighters)
davebender
1st Lieutenant
Manfred Weiss produced DB605 engines for Hungarian built Me-109Gs and Me-210Cs. Did Hungarian built DB605 engines have technical problems similiar to Japanese and Italian built DB601 / DB605 engines?
Its interesting remark
What quantity did they produced DB605? When did this happen?I guess that Hungarians either as Italian simply produced DB605 according to german documentation. But Japanese had to modify DB601A to get more power. For ex. they did not change dims. of cylinders. while in DB605 bore was increased.
davebender
1st Lieutenant
Why?
The first Ki-61 prototype didn't fly until December 1941 so it could have been powered by the 1,350 hp DB601E engine from the beginning. Alternately it could have been powered by the 1,340 hp Jumo 211F engine which was also in production during 1941. Both of these German V12s were reliable.
The first Ki-61 prototype didn't fly until December 1941 so it could have been powered by the 1,350 hp DB601E engine from the beginning. Alternately it could have been powered by the 1,340 hp Jumo 211F engine which was also in production during 1941. Both of these German V12s were reliable.
davebender
1st Lieutenant
IMO that was a mistake.
Assisting friendly nations such as Japan, Italy, Hungary, Romania etc. to improve their air forces would strengthen the German strategic position. Allowing them to build 1,350 hp DB601E engines would go a long way towards that objective.
Assisting friendly nations such as Japan, Italy, Hungary, Romania etc. to improve their air forces would strengthen the German strategic position. Allowing them to build 1,350 hp DB601E engines would go a long way towards that objective.
The pressurized water cooling or other techs introduced with these engines may have been treated as a tech nobody else should have access to.
There was also a lot of politics and economic interests involved in those decisions - why give then state-of-the-art tech if older stuff is already a major improvement for them.
There was also a lot of politics and economic interests involved in those decisions - why give then state-of-the-art tech if older stuff is already a major improvement for them.
davebender
1st Lieutenant
That attitude is fine during peacetime but 1941 Germany was fighting for national survival. It might be worth giving away a few technical secrets if that will help the German war effort.
Italian and Germans were spiting themselves from the beginning of the war.
During the Battle of Alam Halfa the Italians were astonished of the sudden appearance of MG 42
whose existance was kept strictly secret by the Germans to the Italians; the Italians repayed with the same money denying the plans of the Class R submarines when the Germans asked for them
(a specialized cargo submarine) that were desperately needed by the Germans to go to the Far East to import rare metals, rubber, morphine etc.....
Not the best way to win a war.
During the Battle of Alam Halfa the Italians were astonished of the sudden appearance of MG 42
whose existance was kept strictly secret by the Germans to the Italians; the Italians repayed with the same money denying the plans of the Class R submarines when the Germans asked for them
(a specialized cargo submarine) that were desperately needed by the Germans to go to the Far East to import rare metals, rubber, morphine etc.....
Not the best way to win a war.
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Shortround6
Major General
I am not sure why the Germans would need the planes for a cargo submarine. The idea was not new or much of a secret.
Considering this:
German submarine Deutschland - Wikipedia, the free encyclopedia
The Germans must have been keeping secrets from themselves if they needed Italian submarine plans
Considering this:
German submarine Deutschland - Wikipedia, the free encyclopedia
The Germans must have been keeping secrets from themselves if they needed Italian submarine plans
All the design offices in Kriegsmarine or related industries had plenty of work to try to upgrade the VII, IX and XIV and starting to work at the XXI and XXIII models. Just to design a new submarine from scratch (Deutschland was of IWW vintage) Germans probably would have employed more than one year. Engineers and draughtsmen to design a submarine are not to be easily found.
Those raw materials in 1942 were desperately needed, expecially the metals for the jet turbines, a delay of one or more years would have been the difference from life to death.
When, after September 8th, 1943 the Germans captured the remaining Italian submarines in Bordeaux, they were in a hurry transformed in cargo submarines and sent to the Far East, as those submarines were bigger than the German ones.
With very few successes......
Those raw materials in 1942 were desperately needed, expecially the metals for the jet turbines, a delay of one or more years would have been the difference from life to death.
When, after September 8th, 1943 the Germans captured the remaining Italian submarines in Bordeaux, they were in a hurry transformed in cargo submarines and sent to the Far East, as those submarines were bigger than the German ones.
With very few successes......
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davebender
1st Lieutenant
A recipe for disaster during a major war.
Put a 1,350hp DB601E engine in the Macchi C.202 and Italy would have a world class fighter aircraft during 1942. A more effective Italian fighter force means fewer Me-109s and Fw-190s diverted to the Med.
It works the same way in the Pacific. Early production of the Ki-61 powered by a reliable DB601E engine would give the U.S. and Britain a real headache. American air assets that historically went to Europe would be diverted to the Pacific for dealing with the Ki-61s. That takes some pressure off the Luftwaffe and every little bit helps.
Put a 1,350hp DB601E engine in the Macchi C.202 and Italy would have a world class fighter aircraft during 1942. A more effective Italian fighter force means fewer Me-109s and Fw-190s diverted to the Med.
It works the same way in the Pacific. Early production of the Ki-61 powered by a reliable DB601E engine would give the U.S. and Britain a real headache. American air assets that historically went to Europe would be diverted to the Pacific for dealing with the Ki-61s. That takes some pressure off the Luftwaffe and every little bit helps.
Where does this statement come from? What is official source of it?
Or this is only your guess?
Kawasaski began manufacturing of licensed DB-601A engine so non of other engines could appear to be Ki-61 installed on either JuMo or Merlin or Allison alike.
