# ALFA 24 HP

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Motor vehicle

ALFA 24 HP 1910 ALFA 24 HP Torpedo Castagna in Museo Storico Alfa Romeo Overview Manufacturer ALFA Production 1910–1914 Assembly Portello, Milan, Italy Designer Giuseppe Merosi Body and chassis Body style Torpedo Limousine Baquet (tipo corsa)[1] Layout Front-engine, rear-wheel drive Powertrain Engine 4.1 L I4 Transmission 4-speed manual[2] Dimensions Wheelbase 3,200 mm (126.0 in)[1] Length 4,250 mm (167.3 in) Width 1,550 mm (61.0 in) Height 1,700 mm (66.9 in) Curb weight 1,000 kg (2,205 lb)[1] (torpedo) Chronology Predecessor Darracq 14/16 HP[3] Successor 20/30 HP

The **ALFA 24 HP** is a 4.1-litre [four-cylinder](/source/Inline-four_engine) passenger car, the first model produced by [Italian](/source/Italy) car manufacturer ALFA (*Anonima Lombarda Fabbrica Automobili*), which in 1919 would become [Alfa Romeo](/source/Alfa_Romeo). It was introduced in 1910, the year ALFA was founded, and produced until 1914 in ALFA's [Portello](/source/Portello_(district_of_Milan)) factory near Milan. The model's name comes from its [tax horsepower](/source/Tax_horsepower) rating, then frequently used as vehicle designation.

The 24 HP was commercially successful and continued to be developed for a decade. In 1914 some updates transformed the 24 HP into the **ALFA 20-30 HP**, produced in 1914 and 1915—with some hundred cars assembled after the war in 1920. In turn the 20-30 HP evolved into the 1921–22 [Alfa Romeo 20-30 ES Sport](/source/Alfa_Romeo_20%2F30_HP#Alfa_Romeo_20-30_ES_Sport), the first car to be badged [Alfa Romeo](/source/Alfa_Romeo) from its introduction.

In total the 24 HP and 20-30 HP were produced in 680 examples.

## History

### Background and development

ALFA was born from *Società Italiana Automobili Darracq—Milano* (*SIAD*), an unlucky attempt by French manufacturer [Darracq](/source/Automobiles_Darracq_France) and some Italian investors of creating an Italian branch to locally build and sell Darracq cars under license. In Autumn 1909 SIAD [managing director](/source/Managing_director) Cavalier [Ugo Stella](https://en.wikipedia.org/w/index.php?title=Ugo_Stella&action=edit&redlink=1) tasked technical director [Giuseppe Merosi](/source/Giuseppe_Merosi) with developing from a blank sheet a new model, designed from the outset for the Italian market—unlike the unsuccessful small Darracqs.[4] Merosi worked on what would become the 24 HP before ALFA was even established: in January the foreign management of the Portello factory was replaced by Italians, and only in June 1910 SIAD changed its denomination to ALFA.[4] Before the Fall of 1910 the first prototype of the 24 HP was completed and tested.[4] Alongside the 24 HP in 1911 Alfa introduced the [12 HP](/source/ALFA_12_HP), somewhat simpler in its construction and equipped with a smaller 2,413 cc engine, later evolved into the [15 HP](/source/ALFA_15_HP) and then into the [15-20 HP](https://en.wikipedia.org/w/index.php?title=ALFA_15-20_HP&action=edit&redlink=1).[5]

### Racing debut

Ronzoni at 1911 Targa Florio

On 14 May 1911 the 24 HP made its racing debut at the 6th [Targa Florio](/source/Targa_Florio).[6][7] A pair of special 24 HP *tipo corsa* (racing type) were built for the occasion, with 2-seat [baquet](/source/Baquet_(car_body_style)) bodywork, an additional 30-litre fuel tank behind the seats, two spare tyres, and an engine tuned to 45 bhp (34 kW) at 2,400 rpm.[8] Weighing 870 kg (1,918 lb) (as opposed to 1,000 kg (2,205 lb) for a torpedo-bodied standard 24 HP), the car had a top speed of 110 km/h (68 mph).[9] Both drivers (Nino Franchini and Ugo Ronzoni) had to retire on the third and last lap of the course—the first because of an accident, the second because of physical exhaustion.[7]

### Production and evolution

The 24 HP was sold solely as bare chassis. It was made in five series, named with letters from A to E. The series E introduced in 1914 showed the most significant revisions, so much that the model was renamed ALFA 20-30 HP.

#### 24 HP A, B, C and D

- Series A and B, produced in 1910–11 and 1912 respectively, were of 50 cars each. The engine produced 42 bhp (31 kW) at 2,200 rpm, and these cars could reach 100 km/h (62 mph).[1]

- Series C and D, produced in 1913 and 1914 respectively, were roughly of 100 cars each. These adopted the more powerful engine of the 1911 *tipo corsa*; output was now 45 bhp (34 kW) at 2,400 rpm and top speed 105 km/h (65 mph).[1] The [axle tracks](/source/Axle_track) were also widened front and rear—1.45 m (57 in) instead of the previous 1.35 m (53 in)

#### ALFA 20-30 HP

Main article: [ALFA 20/30 HP](/source/ALFA_20%2F30_HP)

Motor vehicle

ALFA 20-30 HP Giulio Ramponi and an A.L.F.A 24 HP (or 20-30 HP) around 1919/20 Overview Manufacturer ALFA, Alfa Romeo Production 1914–1915, 1920 Chronology Predecessor ALFA 24 HP Successor Alfa Romeo 20-30 ES Sport

The **ALFA 20-30 HP** of 1914 and 1915, or ALFA 24 HP series E, was an update of the earlier 24 HP. The in-block camshaft was now chain- instead of gear-driven, the engine produced 49 bhp (37 kW) at 2,400 rpm, and top speed was 115 km/h (71 mph).[1]

Although Italy initially remained neutral until 1915, with the outbreak of [First World War](/source/First_World_War) in 1914 international demand for motor cars declined sharply. As Alfa Romeo turned to wartime production, in 1915 frames and parts for almost 100 20-30 HP cars were set aside unused.[4] They were assembled five years later when the company, which by then had been taken over by [Nicola Romeo](/source/Nicola_Romeo) and renamed [Alfa Romeo](/source/Alfa_Romeo), restarted automobile production after the war.[4] 95 examples were built in 1920, becoming the first cars badged Alfa Romeo, together with the [ALFA 15-20 HP](https://en.wikipedia.org/w/index.php?title=ALFA_15-20_HP&action=edit&redlink=1) assembled the same year, which had followed a similar fate.

During 1920 the 20-30 HP was developed into the larger displacement, shorter wheelbase Alfa Romeo 20-30 ES Sport, the first car to be badged Alfa Romeo from its introduction.[10] The 20-30 ES was produced in 1921 and 1922 in 124 examples.[11]

#### Production numbers

- ALFA 24 HP and derivatives, production by year[12] Year 1910 1911 1912 1913 1914 1915 1916–19 1920 Model total Series A B C D E World War I E 24 HP 10 40 50 103 97 — — — 300 20-30 HP — — — — — 100 185 95 380 Grand total 680

## Specifications

The 24 HP and its derivatives were based on a [ladder chassis](/source/Ladder_chassis) of C-shaped stamped steel rails.

Its engine was a 4,084 cc or 249.2 cu in (bore and stroke 100 x 130 mm, [compression ratio](/source/Compression_ratio) 4.15:1) [sidevalve](/source/Sidevalve) [inline-four cylinder](/source/Inline-four_engine), fed by a single vertical [carburettor](/source/Carburettor).[1] [Cylinder block](/source/Cylinder_block) and [cylinder head](/source/Cylinder_head) were *[en bloc](/source/Monobloc_engine)*, and made of [cast iron](/source/Cast_iron); the [crankcase](/source/Crankcase) was cast [aluminium](/source/Aluminium), incorporating the four engine mountings.[1] The single in-block [camshaft](/source/Camshaft) was driven by a [gear train](/source/Gear_train) on the original 24 HP, and by a more silent [chain](/source/Chain) on its evolution, the 20-30 HP.

The driveline comprised a dry multi-plate [clutch](/source/Clutch), a four-speed [gearbox](/source/Gearbox) and a one-piece [propeller shaft](/source/Propeller_shaft), spinning inside a tube attached to the rear differential housing.[1] At its open end, towards the gearbox, this tube forked out into two ends which, linked to the chassis, located the rear axle. The gearbox was positioned towards the middle of the chassis, almost underneath the driver, rather than in block with the engine—to which it was connected by a short propshaft. Front and rear [solid axles](/source/Solid_axle) were sprung on longitudinal semi-elliptic [leaf springs](/source/Leaf_spring). Brakes were [drums](/source/Drum_brake) on the rear wheels, with both pedal and hand controls. The wheels had wooden spokes.

## References

### Notes

1. ^ [***a***](#cite_ref-FOOTNOTEFusi19783_1-0) [***b***](#cite_ref-FOOTNOTEFusi19783_1-1) [***c***](#cite_ref-FOOTNOTEFusi19783_1-2) [***d***](#cite_ref-FOOTNOTEFusi19783_1-3) [***e***](#cite_ref-FOOTNOTEFusi19783_1-4) [***f***](#cite_ref-FOOTNOTEFusi19783_1-5) [***g***](#cite_ref-FOOTNOTEFusi19783_1-6) [***h***](#cite_ref-FOOTNOTEFusi19783_1-7) [***i***](#cite_ref-FOOTNOTEFusi19783_1-8) [Fusi (1978)](#CITEREFFusi1978), p. 3.

1. **[^](#cite_ref-carfolio.com_2-0)** ["Technical specifications of 1910 Alfa 24 HP A"](http://www.carfolio.com/specifications/models/car/?car=51348). *carfolio.com*. Retrieved 4 January 2008.

1. **[^](#cite_ref-targaflorio.info_3-0)** ["DARRACQ"](http://www.targaflorio.info/darracq.htm). *targaflorio.info*. [Archived](https://web.archive.org/web/20080614083059/http://www.targaflorio.info/darracq.htm) from the original on 14 June 2008. Retrieved 2008-07-22.

1. ^ [***a***](#cite_ref-FOOTNOTEFusi19781–2_4-0) [***b***](#cite_ref-FOOTNOTEFusi19781–2_4-1) [***c***](#cite_ref-FOOTNOTEFusi19781–2_4-2) [***d***](#cite_ref-FOOTNOTEFusi19781–2_4-3) [***e***](#cite_ref-FOOTNOTEFusi19781–2_4-4) [Fusi (1978)](#CITEREFFusi1978), p. 1–2.

1. **[^](#cite_ref-FOOTNOTEFusi197817–18_5-0)** [Fusi (1978)](#CITEREFFusi1978), p. 17–18.

1. **[^](#cite_ref-FOOTNOTEFusi19781_6-0)** [Fusi (1978)](#CITEREFFusi1978), p. 1.

1. ^ [***a***](#cite_ref-targapedia_1911_7-0) [***b***](#cite_ref-targapedia_1911_7-1) ["Targa Florio 1911—Classifica ragionata"](https://www.targapedia.com/targa-florio/1910s/targa-florio-1911). *targapedia.com* (in Italian). Retrieved 12 August 2015.

1. **[^](#cite_ref-FOOTNOTEFusi197811_8-0)** [Fusi (1978)](#CITEREFFusi1978), p. 11.

1. **[^](#cite_ref-FOOTNOTEFusi19783,_11_9-0)** [Fusi (1978)](#CITEREFFusi1978), p. 3, 11.

1. **[^](#cite_ref-FOOTNOTEFusi197844–45_10-0)** [Fusi (1978)](#CITEREFFusi1978), p. 44–45.

1. **[^](#cite_ref-FOOTNOTEFusi197844–46_11-0)** [Fusi (1978)](#CITEREFFusi1978), p. 44–46.

1. **[^](#cite_ref-FOOTNOTEFusi1978849–850_12-0)** [Fusi (1978)](#CITEREFFusi1978), pp. 849–850.

### Bibliography

- Borgeson, Griffith (1990). *The Alfa Romeo Tradition*. City: Haynes (Foulis) Publishing Group Ltd. Somerset, UK. [ISBN](/source/ISBN_(identifier)) [0-85429-875-4](https://en.wikipedia.org/wiki/Special:BookSources/0-85429-875-4).

- Fusi, Luigi (1978). *Alfa Romeo—Tutte le vetture dal 1910—All cars from 1910* (3rd ed.). [Milan](/source/Milan): Emmeti Grafica editrice.

## External links

- Media related to [A.L.F.A 24 HP](https://commons.wikimedia.org/wiki/Category:A.L.F.A_24_HP) at Wikimedia Commons

- [ALFA 24 HP page on the Museo Storico Alfa Romeo website](https://www.museoalfaromeo.com/en-us/collezione/Pages/A-L-F-A--24-HP.aspx)

v t e Alfa Romeo car timeline, 1910s–1940s — next » Ownership Ugo Stella & investors Nicola Romeo IRI Type 1910s 1920s 1930s 1940s 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 4-cyl. 12 HP/15 HP 15-20 HP WWI [α] WWII 24 HP RM 20-30 HP [α] 20-30 ES 40-60 HP 6-cyl. G1 RL 6C 1500/1750/1900 6C 2300 6C 2500 8-cyl. 8C 2300 8C 2900 Grand Prix car GP P1 P2 Tipo A Tipo B (P3) 8C 35 158 158 308 Bi motore 12C 312 512 316 162 Notes [α] 105 A.L.F.A 15-20 HP and 20-30 HP started in 1915 were completed in 1920, after the war, as Alfa Romeo models.

v t e Alfa Romeo A marque of Stellantis Brands Marques Active Alfa Romeo Defunct FNM Divisions, joint-ventures and subsidiaries Former & defunct Fábrica Nacional de Motores (FNM) Alfa Romeo Avio Società Pompe Iniezione Cassani & Affini (SPICA) Società Franco Italiana Motori (Sofim) Alfa Romeo Nissan Autoveicoli S.p.A. Predecessors & old names Società Italiana Automobili Darracq (S.I.A.D.) (predecessor) Anonima Lombarda Fabbrica Automobili (A.L.F.A.) (old name) Current cars 33 Stradale Giulia Junior Stelvio Tonale Future cars Castello Historic and discontinued models 24 HP 40-60HP 20-30HP G1/G2 RM RL 4C 4C Spider 6C 8C 1900 Matta Giulietta 2000 Giulietta Sprint Speciale Giulia 2600 105/115 Series Coupés GTA Gran Sport Quattroruote Spider (105/115) 1750 Berlina 33 Stradale MiTo Montreal 2000 Berlina Alfasud Alfetta Alfetta GT Sprint Nuova Giulietta Giulietta Alfa 6 Arna 33 75 90 164 SZ RZ 155 GTV Spider (916) 145 146 156 166 147 GT 159 Brera Spider (939) 8C Competizione 8C Spider Concept cars 1000 Abarth 2000 Sportiva 2uettottanta 33.2 4C Concept BAT series Bella Brera Caimano Canguro Carabo Dardo Delfino Disco Volante Disco Volante (2013) Diva Eagle Giulia Sport Gloria Iguana Issima Kamal Monospider Navajo New York Taxi Nuvola Pandion Proteo Sportut Scarabeo Scarabeo II Scighera Tipo 103 Visconti TZ3 Vivace Vola Zeta 6 Tonale Concept Buses 40A 80A 85A 110A 140A 150A 430A 500A 800A 900A 902A 950A Mille Trolleybuses 110AF 140AF 800AF 900AF Mille AF Trucks 50 80 85 110 350 430 450 500 800 900 950 Mille A15 A19 A38 F20 Racing cars Grand Prix P1 P2 P3 Tipo A Tipo B (P3) Tipo C (8C-35) Tipo 308 Tipo 312 Tipo 316 Bimotore 12C Tipo 512 158/159 Alfetta TZ/TZ2 GTA Tipo 33 177 179 182 183T 184T 185T SE 048SP 155 V6 TI Alfa Special Vans Romeo A11/F11 A12/F12 AR6 AR8 Motorsport Companys Alfa Romeo in motorsport Alfa Romeo in Formula One (Results) Scuderia Ferrari Alfa Corse Autodelta N.Technology Jolly Club Alfa GTV Cup Technologies Blue&Me Selespeed Multiair Alfa Romeo engines (aircraft engines) platforms Places and facilities Alfa Romeo Museum Alfa Romeo Arese Plant Alfa Romeo Cassino Plant Alfa Romeo Pomigliano d'Arco plant Alfa Romeo Portello Plant Balocco People Nicola Romeo Giuseppe Merosi Vittorio Jano Enzo Ferrari Rudolf Hruska Carlo Chiti Gioacchino Colombo Wifredo Ricart Orazio Satta Puliga Giuseppe Busso Ugo Gobbato Sergio Limone Drivers Formula One drivers Tazio Nuvolari Giuseppe Campari Achille Varzi Luigi Arcangeli Clemente Biondetti Antonio Ascari Ugo Sivocci Jean-Pierre Wimille Guy Moll Gastone Brilli-Peri Baconin Borzacchini Other Alfa Romeo I Alfa Romeo II Alfa Romeo III Alfa Romeo Racing Italiano History of Alfa Romeo Category Commons

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Adapted from the Wikipedia article [ALFA 24 HP](https://en.wikipedia.org/wiki/ALFA_24_HP) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/ALFA_24_HP?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.