Light fighters alternatives, 1935-1945 (2 Viewers)

[Howard Gibson]

As noted by the above posters, AI and Wikipedia is meh.


See here for 575 km/h figure for the SAI.207.
Green's books have run their course.

Wikipedia may not be perfect, but neither is anything else. That [citation needed] tag is precisely what Wikipedia is supposed to do.

The aircraft they liked was the S.A.I.403, which incorporated a lot of improvements. 575kph is 350mph, which still is damned impressive for 750hp. Seeing that you have provided an Italian document, I wonder if this is proper English horsepower of 33,000ft.lb/min, which works out to around 746W. Wikipedia describes a metric horsepower in which 75kgf is lifted at 1m/s. This works out to 735W.

 

[tomo pauk]

The aircraft they liked was the S.A.I.403, which incorporated a lot of improvements. 575kph is 350mph, which still is damned impressive for 750hp.

How much they really liked the 403 is open to the debate, since the prototype disintegrated mid-air when the dive tests were conducted, and the pilot was killed due to the malfunction of his parachute. FWIW, machine translated; my bold:
However, there was no time to set up production before the armistice, so the prototype remained the only example produced. In this regard, sources take its destruction before the armistice as certain, while it was carrying out a sinking test in which the wings, of less robust construction than Stefanutti's previous fighters, gave way and detached, with the death of the test pilot Colombo due to the failure of the parachute to function,[2]​[3]​ also bringing this mournful event as the cause of the delay in production and the definitive cessation of interest in the aircraft by foreign companies.

I'd certainly agree that 350 mph on 750 HP is impressive, and I'll reiterate that such a fighter would've been very intersting and useful if it materialized at least a few years before, and of course if it was made strong enough.

 

[topspeed]

The limit on the performance of any piston engined propeller driven aircraft is the propeller. As the propeller tip approaches the speed of sound, the efficiency drops off. There is a good video on propellers on YouTube dating from some time in World War II in which they state that aircraft top speeds will plateau at 500 to 600mph. The official airspeed record is a smidgen less than 530mph.

Computational Fluid Dynamics is the process of modelling the fluid as a series of simultaneous equations, and then solving them. Look up Gaussian Reduction. The resulting matrices are huge and not solvable without powerful computers. I believe they then do it again and again, as they iterate to a solution. Basically, you set this running on your computer, then you find something else to do for a day or two. There was no capacity for this during WWII.

If your analysis assumes that thrust is generated by something other than a propeller with a maximum speed of 530mph, than you have garbage in garbage out.

I am looking a William Green's drawings here (sorry TP!). The S.A.I.403 seems to have had a retractable tail wheel.

Piaggio Avanti and TU-95 typically move 920 km/h....with propellers.

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Sai 403 engine weighed 510 kg dry.

Isotta Fraschini Delta - Wikipedia

en.wikipedia.org

The Ford engine matching the description of 650 hp and a 3-liter displacement is the 3.5-liter Cosworth-Ford HB V8 found in the 1994 Ford Supervan 3. Although the displacement is technically 3.5 liters, it is frequently cited in this context due to its Formula 1-derived origins and the specific 650 horsepower output.

• Vehicle: 1994 Ford Supervan 3
• Engine: Cosworth-Ford HB V8
• Displacement: 3.5 liters
• Power: 650 hp
• Redline: 13,000 rpm
• Significance: This power output exceeded that of the McLaren F1 supercar, which produced 618 hp.

The Ford 3.5L EcoBoost engine itself weighs approximately 449 lb (204 kg), according to official specifications for the V6 EcoBoost family.

The 650 hp figure refers to high-output or heavily modified variants of this engine, such as those used in the Ford GT supercar or tuned by companies like Radical for track applications (producing up to 654 hp). While the stock 3.5L EcoBoost typically produces between 365 hp and 375 hp in standard truck applications, specialized builds can achieve the 650 hp mark through upgrades like turbochargers and internal components without significantly altering the base engine's dry weight.
AI-generated answer. Please verify critical facts.


Ford 3.5L PFDI Specs, Features, Performance & Reviews | Ford Component Sales LLC


Here is 675 hp aviation engine:

ASE-650 SAGA - Aerosport Engineering

Weight is unknown.