Making better Italian aircraft, 1933~1945

[z42]

Now that we're posting pictures of Caproni aircraft, the bestest must be

 

[Shortround6]

Now that we're posting pictures of Caproni aircraft, the bestest must be

View attachment 806630

Means you don't have worry about gun synchronizers though. Lots of room for guns outside the prop arc

 

[Admiral Beez]

I think FIAT, Reggiane and Macchi continuing to make fighters is fine, Germany and Britain are really the only countries that cut down fighter production to two companies.

I'd have Macchi and Reggiane focus on fighters, pumping out as many C.200, C.202, Re.2000, Re.2001 and Re.2002 as possible. I would instruct FIAT's aeronautucals division to focus on getting the best out of its radial engines, Fiat A.74 - Wikipedia

As one of Italy's premier manufactures of trucks and small arms, FIAT can also make more Fiat 626 and 666 trucks, 727 half tracks and tanks/AFVs like the Fiat-Ansaldo armoured cars, plus machine guns and small arms. It's aero engines and trucks where FIAT can make its greatest contribution.

 

[Shortround6]

Going back to the Original post.

Regia Aeronautica does not cancel all development of inline engines in 1933.

Perhaps they should have canceled all existing engines and been open to "new" engines. The Italians could not afford to keep fooling around with slightly modified existing engines.
Putzing around with existing engines puts them in race next to the French with their continued development of the H-S 12X and 12Y engines.

Reggiane successfully produces the Re 101~105 series of engines from 1937 to 1943, the Re 103 seeing widespread use on high-altitude interceptors such as the Ro.58 and Re.2005.

Too late, war is over before they can do anything, now in 1937 they don't know when the war will start but, DB and Junkers started work in 1933, got useable engines in 1938? RR, with 5 different V-12s under their belt first ran the Merlin prototype Oct 15th 1933, work started when? First really satisfactory engine was the 8th version, the Merlin II which started production in mid/late 1937.

The 16-cylinder Fiat AS.8 makes it into production by late 1941, primarily used by fighter aircraft such as the G.55 and C.205.

Again, we are expecting the Italians to develop and put into production a decent engine much quicker than any other nation in the world did it in the same period of time.

The 18-cylinder Alfa Romeo 135 is designed for 87 octane off-the-bat, entering large scale production by 1938, the boosted 136 entering production in 1942.

The 18 cylinder Alfa Romeo 135 is basically two Bristol Mercuries running on the same crankshaft and using a common supercharger.
From an old thread on this site about the Alfa Romeo 135 engine.

Alfa Romeo 136 R.C.25

While researching engines which might have been used by the Axis to design a better fighter and/or bomber in WWII my attention was caught by this Italian engine, which, according to the Wiki (not that I trust it 100%, but it's much more often right than wrong!) says - "...At the time of its...

ww2aircraft.net

Notice the valve gear, lubricated by grease gun.
Notice the obstructions to air flow around the cylinder head (and the general lack of fin area even on the cylinders)
Something that has potential is moving the carb from the side of the supercharger to position with a more central inlet to the compressor?
Basically you have a running 18 cylinder engine, now change just about everything except for a few odd assorted bolts and nuts.

Now the Italians were looking forward, every engine maker worth his slide rule knew that 100 octane fuel was coming, the 2 big questions were when and what the exact composition would be. All 100 octane allowed you to do was use more compression, either in the cylinders or by using more boost or a combination. This meant you needed to make the engine stronger to handle the higher pressure/loads and you needed to figure out how to get rid of the extra heat.

Going back the V-12s, the existing Fiat engines date from 1925 when Fiat discontinued all of the WW I and early 20s engines and based the new engines a common theme/design even though cylinder dimensions varied widely. They wound up with 7 (?) different displacements from 18.7L to 54.5L and a variety direct drive, gear drive and supercharger, non supercharged variations.
From

EarlyEnginesFt

"In 1925 Fiat discontinued all previous models and introduced a new water-cooled 60° V-12 line. Cylinders were machined from steel forgings and had welded-on valve ports and top plate, as well as sheet-steel water jackets. Four vertical valves in each cylinder were operated by two overhead camshafts. The camshafts were geared together and supported by bearings in a split aluminum casing that bolted to each cylinder head. A bevel gear attached to one camshaft end was driven by a vertical drive shaft. Identical cams on each side of a camshaft bearing acted upon the top of a T-shaped bridge that was guided vertically, and whose underside operated each valve pair. Six-throw, seven-main-bearing crankshafts were supported on babbitt-lined bronze plain bearings. A deep-groove ball thrust bearing was used in some direct-drive engines. Articulated connecting rods with H-section shanks were attached to aluminum-alloy trunk type pistons that were cam-ground to compensate for differential expansion at working temperature. Two compression rings and two oil scraper rings, located above and below the piston-pin, were included on each piston. The aluminum crankcase sections were joined along the crankshaft centerline, and the main bearing duralumin caps were held by four bolts each. Most auxiliary drives were contained in a case bolted to the engine rear end. Two Marelli MF 12 magnetos mounted crosswise supplied dual ignition. These were driven through bevel gears from the upper vertical shaft that also drove the inclined camshaft drive shafts. The lower vertical shaft drove the oil pump and water pump through a spur idler gear, and a fuel pump through a horizontal shaft with a worm gear. Duplex carburetors located in the Vee typically supplied three cylinders from each throat. A dry-sump lubrication system was employed."

Improvements needed were one piece blocks, Better bearings, forked connecting rods.
What is unknown from these short descriptions is how good the oil system was, adequate crank bearing area, adequate water flow for higher power ratings, counter weighting for higher RPM (around 2400rpm was a critical area for most V-12s).

If the Italians didn't cancel all liquid cooled engines they sure needed to stop their designers from going in a dozen different directions at once (add I-F other Italian companies to the Fiat projects).

 

[TM06]

I'd have Macchi and Reggiane focus on fighters, pumping out as many C.200, C.202, Re.2000, Re.2001 and Re.2002 as possible. I would instruct FIAT's aeronautucals division to focus on getting the best out of its radial engines, Fiat A.74 - Wikipedia

As one of Italy's premier manufactures of trucks and small arms, FIAT can also make more Fiat 626 and 666 trucks, 727 half tracks and tanks/AFVs like the Fiat-Ansaldo armoured cars, plus machine guns and small arms. It's aero engines and trucks where FIAT can make its greatest contribution.

While that may be true, it also deprives Italy of the G.55 - arguably the best single-seat fighter they made. On the other hand, Macchi didn't make anything other than fighters so assigning them to make things other than fighters might not go to well.

However I would like to note that Fiat-Ansaldo held a monopoly on Italian tank and armour production. There were other manufacturers in Italy at the time that could've helped significantly in the production of AFV's, small arms and logistical vehicles. I'd personally put forward Zagato and Maserati as licensed contractors to build the trucks since they had the most experience next to Alfa Romeo and weren't nearly as busy.
Fiat's burden would be significantly lightened by introducing other companies in the ground sector which would improve production all-around.

-snip-

Those points were mainly as entry points for the discussion rather than anything I was putting forward myself.
Although I will note on the Reggiane engines specifically, they could likely be made earlier due to the continued support of inline engines in this suggestion. The Re 101 would be quite comparable to the Merlin and DB 601. The Re 103 in particular is notable as a high-altitude engine making similar power (even on 87 octane) to the DB 603 and Jumo 213 while being lighter and smaller than either.
Old Machine Press notes that development of the Re 103 was slow, with the design being drawn up in 1940 and an engine being made in 1942 - an earlier start date might push that back a bit?

 

[Shortround6]

According to one source

Italian WW2 vehicles

Italian ww2 soft skin vehicles, trucks, cars, and their armed and armored variants

truck-encyclopedia.com

The Italians had almost 500,000 vehicles of all kinds during WW II.
Not as many as they needed but well ahead of some other German allies

Zagato was a coach builder (bodies) and while talented in both good design for good looks and design for innovative construction, they did not make their own chassis or engines.
The Maserati brothers were very successful race car builders and branched out a tiny bit into very sporty road cars (street legal race cars?) but were hardly what you would contract out army trucks to to (unless you wanted some of the fastest army trucks in the world). Maserati didn't really get into commercial car production until after WW II.

Getting Reggiane to work on the Re 100 series of engines before 1937 means restarting the aviation section of company before 1937.

They just barely got the company to stay in business for the 1st half of the 1930s with a number sell offs, until they got involved with re-armament in 1936 and apparently were subcontracting engines or engine parts to Piaggio

Officine Meccaniche Reggiane - Wikipedia

it.wikipedia.org

Basically the Re 100 series was dream with little hope of producing a viable engine. The US had several companies with much greater back grounds and shop/factory size that failed to turn their designs/prototypes into production engines.

 

[Admiral Beez]

While that may be true, it also deprives Italy of the G.55 - arguably the best single-seat fighter they made. On the other hand, Macchi didn't make anything other than fighters so assigning them to make things other than fighters might not go to well.

True. But it came too late to matter. Maybe if we give Macchi the toss and reassign resources and talent to FIAT we can get the G.55 sooner.

 

[tomo pauk]

While that may be true, it also deprives Italy of the G.55 - arguably the best single-seat fighter they made. On the other hand, Macchi didn't make anything other than fighters so assigning them to make things other than fighters might not go to well.

The gorgeous G.55, despite it's war-fighting qualities, was but a footnote in the scope of the ww2. Italians needed the fighter of similar qualities in good quantities 1941, or latest in 1942. Late 1943 is/was simply not good enough.
In order to have a maneuverable fighter that also has other qualities required (does 380+ mph, has great firepower, long range/radius), a good engine is needed. The engine that is in series production in Italy by that time. Again, from 1941/early-mid 42 on, not in 1943.

 

[Shortround6]

An extra 50-100 DB 605 powered fighters is not going to make more than a day or twos worth of difference to the Invasion of Sicily or to most of the Italian campaign.
Tomo is right, the Italians need better aircraft in 1940-41. And they need a lot of them, not 100-200 more MC 202s while they are still building hundreds of MC 200s in the same factories or building CR 42s.

 

[mack8]

There are many ways the italians could have done better re aircraft design and production, on the narrow subject of engines my favourite TL is one in which, first, the italians somehow crossbreed their radials with the japanese radials. Look at indicators such as HP/litre that the japanese engines had compared to contemporary italian radials, or the fact the the japanese built tens of thousands of 2-speed engines while the italian never more than a few prototypes, and we can see the japanese radials were lightyears ahead.

So imagine A.74 with Kinsei family power levels, or P.XI with Ha-41/109 power levels, or A.80 with Kasei power, or P.XII with Ha-104 power (all these engine are the closest equivalents to eachother in capacity). This will transform italian aircraft performance.

The second is building as many DBs and Jumos if possible under licence at every company that could, fe Fiat, Alfa Romeo and Isotta Fraschini (Piaggio remains focused on radials). This will give then a lot more high performance fighters that they badly need and perhaps some good inline powered bombers too.

Between these two changes, the italian aircraft ought to be much more formidable opponents. This not even touching other possibilities like better design practices, increased production through various means (especially rationalizing production and stomping on petty turf politics), or more metal-built aircraft (they need to somehow get or produce more aluminium for this though)

 

[z42]

Not sure how much contact there was between the Italians and the Japanese, but if feasible this could be interesting. The Japanese radials seem to be a step beyond the other Axis ones.

 

[tomo pauk]

There are many ways the italians could have done better re aircraft design and production, on the narrow subject of engines my favourite TL is one in which, first, the italians somehow crossbreed their radials with the japanese radials. Look at indicators such as HP/litre that the japanese engines had compared to contemporary italian radials, or the fact the the japanese built tens of thousands of 2-speed engines while the italian never more than a few prototypes, and we can see the japanese radials were lightyears ahead.

Italian radials of the day were also with the outdated superchargers. Toss in that, as it was the case with almost 100% radials of the day, that the intake elbow was squished/congested, and the altitude performance suffered.
There was a way out of this even by the late 1930s - actually adopt the 2-stage superchargers for military aircraft. Italians have had a 2-stage S/C on the record-setting P.XI.RC.100 engine, and they know that Bristol, Farman and Jumo are/were working on such stuff in the 1930s. It will not give the world to the Italians, but it might've resulted in the Italian equivalent of the 2-stage R-1830, power/weight wise before 1940. Applied on the Piaggio 18 cyl types, it should be better than the BMW 801 at the higher altitudes, and lighter.
Similar principle can be be applied to the V12 engines, netting the Italians the equivalent of a DB 601E or the 605A by the time shooting starts.

Once the importance of the less cluttered intake elbow and more refined is understood, go on with these, especially since that also improves the 1-stage engines.

Japanese were converts to the 3-bearings idea for the 2-row radials (already by 1941 in mass production on all important radials?), I'm not sure that Italians ever gotten there except on the A.74.

 

[Shortround6]

There are many ways the italians could have done better re aircraft design and production, on the narrow subject of engines my favourite TL is one in which, first, the italians somehow crossbreed their radials with the japanese radials. Look at indicators such as HP/litre that the japanese engines had compared to contemporary italian radials, or the fact the the japanese built tens of thousands of 2-speed engines while the italian never more than a few prototypes, and we can see the japanese radials were lightyears ahead.

This isn't quite as bad as it appears. The Japanese had one 2 speed engine in production before 1942. The Japanese introduced several more two speed engines in the 2nd half of 1942.
So you have about 1 year of overlap of two speed Japanese engines and no two speed Italian engines before the Italians surrender in 1943.

Now for the Italians they have a few other problems. It doesn't matter what kind of supercharger you stick on the back of most radials, if you are still using the cooling fins of the existing engines. If you are trying to make more power and do it in thinner air (higher altitude) you need more, thinner, deeper, more closely spaced fins on the cylinders and cylinder heads or the engine overheats and goes perhaps goes into melt down/oil failure or even (if not throttled back) into detonation.
A better supercharger can allow a bit more boost for the same power in and it can give you a bit more air at the same temperature. But the Italians really need to re-tool cylinder and cylinder head production to really get anywhere. And this gets expensive real quick. You want to make fins 6mm deeper on a forged steel cylinder barrel? you need to make forgings 12mm bigger in diameter and then machine all the excess steel away. You want deeper fins on the aluminum head? you need new, bigger casting molds and you need new slitting saws and .......and....... and.
P & W figured out how to make a R-1830 make 1200hp at 3700ft in low gear and 900hp at17,400ft using 91 octane fuel. When they switched to 100 octane they got 1200hp at 4900ft and in high gear they got 1050hp at 13,100ft. Supercharger could not supply anymore air or engine couldn't cool at higher altitudes?
Please note that the engine used in the Wildcat with two stage supercharger and intercooler and 100 octane fuel was only rated at 1000hp at 19,000ft. They would not use the full 2700rpm in high gear. They needed the two stage supercharger, the intercoolers and 100 octane fuel to get 100hp more 1600ft higher up?
It took P & W about 3 more years, new bearings and new cylinders with cooling muffs to get to 1350hp at low level.

 

[tomo pauk]

This isn't quite as bad as it appears. The Japanese had one 2 speed engine in production before 1942. The Japanese introduced several more two speed engines in the 2nd half of 1942.
So you have about 1 year of overlap of two speed Japanese engines and no two speed Italian engines before the Italians surrender in 1943.

Japanese engines were, in general, with greater power than the Italian stuff, while still being light/very light and without the reliability problems usually attributed to the engines that have a high power/weight ratio. Also very compact, bar the Kasei.

Now for the Italians they have a few other problems. It doesn't matter what kind of supercharger you stick on the back of most radials, if you are still using the cooling fins of the existing engines. If you are trying to make more power and do it in thinner air (higher altitude) you need more, thinner, deeper, more closely spaced fins on the cylinders and cylinder heads or the engine overheats and goes perhaps goes into melt down/oil failure or even (if not throttled back) into detonation.

Both Bristol and Piaggio were doing just that in the 1930s: sticking a 2-stage S/C (in one way or another) on the legacy power sections in order to much improve the altitude power. Unfortunately, neither company made the 2-stage supercharged military engines in series, let alone mass producing them.

P & W figured out how to make a R-1830 make 1200hp at 3700ft in low gear and 900hp at17,400ft using 91 octane fuel. When they switched to 100 octane they got 1200hp at 4900ft and in high gear they got 1050hp at 13,100ft. Supercharger could not supply anymore air or engine couldn't cool at higher altitudes?
Please note that the engine used in the Wildcat with two stage supercharger and intercooler and 100 octane fuel was only rated at 1000hp at 19,000ft. They would not use the full 2700rpm in high gear. They needed the two stage supercharger, the intercoolers and 100 octane fuel to get 100hp more 1600ft higher up?
It took P & W about 3 more years, new bearings and new cylinders with cooling muffs to get to 1350hp at low level.

The impellers that the P&W used on the R-1830s, including the 2-stage versions, were outdated, without the inducer blades.
While the Italians don't have a hi-oct fuel supply, they can have the 2-stage S/Cs installed on the radial engines that are 38+ liters, compared with the 30 liter R-1830.
Even better if the V12s got the 2-stagers, or the Piaggio 18 cyl types.

 

[Shortround6]

Both Bristol and Piaggio were doing just that in the 1930s: sticking a 2-stage S/C (in one way or another) on the legacy power sections in order to much improve the altitude power.

Not really, Bristol could build a high altitude engine, high being around 15,000ft. What they also wound up with was an engine that was pretty wimpy for take-off. The two speed super charger allowed for good take-off performance while still keeping the altitude performance.
I may be arguing about perspective. Bristol offered both medium and high altitude single speed engines. The two speed engines never offered any better performance at altitude over the high altitude single speed engine, it could offer around 200hp more for take-off. The flip side is that the two speed engine did offer better altitude performance than the single speed medium altitude engine, by thousands of feet. But take off power was a lot closer to the between the medium altitude engine and the two speed.
This is one reason that two speed engines showed up first (usually) in bombers and transports rather than fighters.

 

[tomo pauk]

Not really, Bristol could build a high altitude engine, high being around 15,000ft. What they also wound up with was an engine that was pretty wimpy for take-off. The two speed super charger allowed for good take-off performance while still keeping the altitude performance.

I was referring to the Pegasus that powered the Type 138 high-altitude aircraft.

 

[MikeMeech]

Hi
Bristol engines were used for various high altitude flights; Vickers Vespa VII with Pegasus 'S' reached over 43,000 feet in September 1932. The 'ordinary' Vespa III powered by the Jupiter VI engine in Bolivia was regularly flying between 24 - 25,000 feet and achieved a max height of about 27,000 feet.
During the Everest Expedition in 1933 the Westland PV.3, Pegasus IS.3 and Westland PV.6/Wallace flew over Mt. Everest so over 29,000 ft.
The Bristol 138A, already mentioned, with Pegasus PE.6S got to 49,967 ft. in 1936 and 53,937 ft. in 1937.
Just info for interest.

Mike

 

[mack8]

This isn't quite as bad as it appears. The Japanese had one 2 speed engine in production before 1942. The Japanese introduced several more two speed engines in the 2nd half of 1942.
So you have about 1 year of overlap of two speed Japanese engines and no two speed Italian engines before the Italians surrender in 1943.

Now for the Italians they have a few other problems. It doesn't matter what kind of supercharger you stick on the back of most radials, if you are still using the cooling fins of the existing engines. If you are trying to make more power and do it in thinner air (higher altitude) you need more, thinner, deeper, more closely spaced fins on the cylinders and cylinder heads or the engine overheats and goes perhaps goes into melt down/oil failure or even (if not throttled back) into detonation.
A better supercharger can allow a bit more boost for the same power in and it can give you a bit more air at the same temperature. But the Italians really need to re-tool cylinder and cylinder head production to really get anywhere. And this gets expensive real quick. You want to make fins 6mm deeper on a forged steel cylinder barrel? you need to make forgings 12mm bigger in diameter and then machine all the excess steel away. You want deeper fins on the aluminum head? you need new, bigger casting molds and you need new slitting saws and .......and....... and.
P & W figured out how to make a R-1830 make 1200hp at 3700ft in low gear and 900hp at17,400ft using 91 octane fuel. When they switched to 100 octane they got 1200hp at 4900ft and in high gear they got 1050hp at 13,100ft. Supercharger could not supply anymore air or engine couldn't cool at higher altitudes?
Please note that the engine used in the Wildcat with two stage supercharger and intercooler and 100 octane fuel was only rated at 1000hp at 19,000ft. They would not use the full 2700rpm in high gear. They needed the two stage supercharger, the intercoolers and 100 octane fuel to get 100hp more 1600ft higher up?
It took P & W about 3 more years, new bearings and new cylinders with cooling muffs to get to 1350hp at low level.

On the issue of 2S engines, actually seems the situation is even worse than it looks. Definitely the Ha-101/Kasei and Ha-102/Zuisei-20 series were in production in 1941, and at least the Ha-101/Kasei started production in 1940 (the first 30 G6Ms wingtip escorts were iirc ready by late 1940 before switching to G4M1). In 1942 the Ha-109 and Sakae-20 were in full production.

Just going by memory above, USSBS is a fantastic source to see which japanese engines and airframes were produced when.

But nevermind 2S engines, just looking at the A.74 which was the best italian radial concerning HP/litre ratio, diameter, reliability etc. it was still behind japanese contemporaries ie Kinsei-40, Ha-26/Zuisei, Ha-25 Sakae. A rough calculation shows that if the A.74 had a similar HP/litre ratio as any of the above engines (or even just an average), should have given from 1000 to 1060 HP emergency power, call it 1030 HP average. But the A.74 was 70 HP short of that ie 960 HP emergency.

And getting back to 2S engine, looking at what powers Sakae-20, Kinsei-50 and Ha-102/Zuisei-20, a nipponized 2-speed A.74 should have reached 1200 to 1260 HP emergency. That's a mouthwatering amount of power actually to imagine the italians having on MC.200 or G.50 or even the lowly CR.42 biplane.

The above just considering the best italian radial, the situation is even more damning when comparing other major italian radials with their nearest japanese counterparts (for instance Fiat A.80 with Kasei, or P.XI/P.XIX with Ha-41/109 etc.)

 

[mack8]

On another note, are there any figures for the italian aircraft and engine production before and during WW2? Would also be instructive to compare with contemporary japanese and french aircraft production, and would serve to put in perspective the italian situation (and potential).

There are some figures found on wiki, but i think they are not that accurate and in any case it only starts in 1939. While for engines there is nothing much really, i have in my mind a figure of 21,000 engines but i'm not sure, and certainly no breakdown by type which would be very interesting to see. Was there ever a USSBS or USSBS style analysis done of the italian aircraft industry after the war that might be available online somewhere?

 

[Shortround6]

Something to look at for the engines is power to weight. Aircraft designers don't care what the displacement of an engine is.
The Italian engines still don't look great but it gets a little closer.

in terms of general industrial capacity (very general) Japan was making about 4 times the steel that Italy was before war damage impacted things. In 1941 Canada made more steel than Italy.