{{Infobox automobile | name = ALFA 24 HP | image = ALFA-24-HP.jpg | caption = 1910 ALFA 24 HP Torpedo [[Carrozzeria Castagna|Castagna]] in [[Museo Storico Alfa Romeo]] | manufacturer = [[Alfa Romeo|ALFA]] | assembly = [[Portello (district of Milan)|Portello, Milan]], Italy | production = 1910–1914 | body_style = {{unbulleted list|[[Torpedo (car)|Torpedo]]|[[Limousine]]|[[Baquet (car body style)|Baquet]] (''tipo corsa''){{sfnp|Fusi|1978|p=3}}}} | class = | layout = [[Front-engine, rear-wheel drive layout|Front-engine, rear-wheel drive]] | engine = 4.1 L [[Inline-four engine|I4]] | transmission = 4-speed [[Manual transmission|manual]]<ref name="carfolio.com">{{cite web |url=http://www.carfolio.com/specifications/models/car/?car=51348 |title=Technical specifications of 1910 Alfa 24 HP A |website=carfolio.com |access-date=4 January 2008}}</ref> | wheelbase = {{convert|3200|mm|in|1|abbr=on}}{{sfnp|Fusi|1978|p=3}} | length = {{convert|4250|mm|in|1|abbr=on}} | width = {{convert|1550|mm|in|1|abbr=on}} | height = {{convert|1700|mm|in|1|abbr=on}} | weight = {{convert|1000|kg|lb|0|abbr=on}}{{sfnp|Fusi|1978|p=3}} (torpedo) | predecessor = [[Automobiles Darracq France|Darracq 14/16 HP]]<ref name="targaflorio.info">{{cite web |url=http://www.targaflorio.info/darracq.htm |website=targaflorio.info |title=DARRACQ |access-date=2008-07-22 |archive-url=https://web.archive.org/web/20080614083059/http://www.targaflorio.info/darracq.htm |archive-date=14 June 2008 |url-status=live}}</ref> | successor = [[ALFA 20/30 HP|20/30 HP]] | designer = [[Giuseppe Merosi]] }}
The '''ALFA 24 HP''' is a 4.1-litre [[Inline-four engine|four-cylinder]] passenger car, the first model produced by [[Italy|Italian]] car manufacturer ALFA (''Anonima Lombarda Fabbrica Automobili''), which in 1919 would become [[Alfa Romeo]]. It was introduced in 1910, the year ALFA was founded, and produced until 1914 in ALFA's [[Portello (district of Milan)|Portello]] factory near Milan. The model's name comes from its [[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 {{nowrap|'''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 HP#Alfa Romeo 20-30 ES Sport|Alfa Romeo 20-30 ES Sport]], the first car to be badged [[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 [[Automobiles Darracq France|Darracq]] and some Italian investors of creating an Italian branch to locally build and sell Darracq cars under license. In Autumn 1909 SIAD [[managing director]] Cavalier [[Ugo Stella]] tasked technical director [[Giuseppe Merosi]] with developing from a blank sheet a new model, designed from the outset for the Italian market—unlike the unsuccessful small Darracqs.{{sfnp|Fusi|1978|p=1–2}} 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.{{sfnp|Fusi|1978|p=1–2}} Before the Fall of 1910 the first prototype of the 24 HP was completed and tested.{{sfnp|Fusi|1978|p=1–2}} Alongside the 24 HP in 1911 Alfa introduced the [[ALFA 12 HP|12 HP]], somewhat simpler in its construction and equipped with a smaller 2,413 cc engine, later evolved into the [[ALFA 15 HP|15 HP]] and then into the [[ALFA 15-20 HP|15-20 HP]].{{sfnp|Fusi|1978|p=17–18}}
===Racing debut=== [[Image:1911-05-14 Targa Florio A.L.F.A 24 HP Ronzoni.jpg|thumb|left|Ronzoni at 1911 Targa Florio]] On 14 May 1911 the 24 HP made its racing debut at the 6th [[Targa Florio]].{{sfnp|Fusi|1978|p=1}}<ref name="targapedia 1911">{{cite web |url=https://www.targapedia.com/targa-florio/1910s/targa-florio-1911 |title=Targa Florio 1911—Classifica ragionata |website=targapedia.com |language=it |access-date=12 August 2015}}</ref> A pair of special 24 HP ''tipo corsa'' (racing type) were built for the occasion, with 2-seat [[Baquet (car body style)|baquet]] bodywork, an additional 30-litre fuel tank behind the seats, two spare tyres, and an engine tuned to {{convert|45|bhp|abbr=on}} {{nowrap|at 2,400 rpm}}.{{sfnp|Fusi|1978|p=11}} Weighing {{convert|870|kg|lbs|0|abbr=on}} (as opposed to {{convert|1000|kg|lbs|0|abbr=on}} for a torpedo-bodied standard 24 HP), the car had a top speed of {{convert|110|km/h|mph|0|abbr=on}}.{{sfnp|Fusi|1978|p=3, 11}} 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.<ref name="targapedia 1911" />
===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 {{convert|42|bhp|abbr=on}} {{nowrap|at 2,200 rpm}}, and these cars could reach {{convert|100|km/h|mph|0|abbr=on}}.{{sfnp|Fusi|1978|p=3}} * 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 {{convert|45|bhp|abbr=on}} {{nowrap|at 2,400 rpm}} and top speed {{convert|105|km/h|mph|0|abbr=on}}.{{sfnp|Fusi|1978|p=3}} The [[axle track]]s were also widened front and rear—{{convert|1.45|m|in|0|abbr=on}} instead of the previous {{convert|1.35|m|in|0|abbr=on}}
====ALFA 20-30 HP==== {{main|ALFA 20/30 HP}} {{Infobox automobile | name = ALFA 20-30 HP | image = 1919 A.L.F.A. 24 HP (20-30 HP) Ramponi.jpg | caption = [[Giulio Ramponi]] and an A.L.F.A 24 HP (or 20-30 HP) around 1919/20 | manufacturer = ALFA, Alfa Romeo | production = 1914–1915, 1920 | predecessor = ALFA 24 HP | successor = [[Alfa Romeo 20/30 HP#Alfa Romeo 20-30 ES Sport|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 {{convert|49|bhp|abbr=on}} {{nowrap|at 2,400 rpm}}, and top speed was {{convert|115|km/h|mph|0|abbr=on}}.{{sfnp|Fusi|1978|p=3}}
Although Italy initially remained neutral until 1915, with the outbreak of [[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.{{sfnp|Fusi|1978|p=1–2}} They were assembled five years later when the company, which by then had been taken over by [[Nicola Romeo]] and renamed [[Alfa Romeo]], restarted automobile production after the war.{{sfnp|Fusi|1978|p=1–2}} 95 examples were built in 1920, becoming the first cars badged Alfa Romeo, together with the [[ALFA 15-20 HP]] 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.{{sfnp|Fusi|1978|p=44–45}} The 20-30 ES was produced in 1921 and 1922 in 124 examples.{{sfnp|Fusi|1978|p=44–46}}
====Production numbers==== :{| class="wikitable" style="font-size:90%; text-align:center;" |+ ALFA 24 HP and derivatives, production by year{{sfnp|Fusi|1978|pages=849–850}} ! Year ||width=30em| 1910 ||width=30em| 1911 ||width=30em| 1912 ||width=30em| 1913 ||colspan=2| 1914 ||width=30em| 1915 || 1916–19 ||width=30em| 1920 ||rowspan=2 style="line-height:1.3em;"| Model<br />total |- ! Series |colspan=2| A || B || C ||width=30em| D ||colspan=2| E || rowspan=3| World War I || E |- | 24 HP || 10 || 40 || 50 || 103 || 97 || — || — || — || {{formatnum:{{#EXPR:10+40+50+103+97}}}} |- | 20-30 HP || — || — || — || — || — ||width=30em| 100 || 185 || 95 || {{formatnum:{{#EXPR:100+185+95}}}} |- ! '''Grand total''' |colspan=9| || {{formatnum:{{#EXPR:10+40+50+103+97+100+185+95}}}} |}
==Specifications==
The 24 HP and its derivatives were based on a [[ladder chassis]] of C-shaped stamped steel rails.
Its engine was a {{convert|4084|cc|cuin||abbr=on|disp=or}} (bore and stroke 100 x 130 mm, [[compression ratio]] 4.15:1) [[sidevalve]] [[Inline-four engine|inline-four cylinder]], fed by a single vertical [[carburettor]].{{sfnp|Fusi|1978|p=3}} [[Cylinder block]] and [[cylinder head]] were ''[[Monobloc engine|en bloc]]'', and made of [[cast iron]]; the [[crankcase]] was cast [[aluminium]], incorporating the four engine mountings.{{sfnp|Fusi|1978|p=3}} The single in-block [[camshaft]] was driven by a [[gear train]] on the original 24 HP, and by a more silent [[chain]] on its evolution, the 20-30 HP.
The driveline comprised a dry multi-plate [[clutch]], a four-speed [[gearbox]] and a one-piece [[propeller shaft]], spinning inside a tube attached to the rear differential housing.{{sfnp|Fusi|1978|p=3}} 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 axle]]s were sprung on longitudinal semi-elliptic [[leaf spring]]s. Brakes were [[Drum brake|drums]] on the rear wheels, with both pedal and hand controls. The wheels had wooden spokes.
==References==
===Notes=== {{reflist}}
===Bibliography=== {{refbegin}} * {{cite book |last=Borgeson |first=Griffith |title=The Alfa Romeo Tradition |publisher=Haynes (Foulis) Publishing Group Ltd. Somerset, UK |location=City |year=1990 |isbn=0-85429-875-4}} * {{cite book |first=Luigi |last=Fusi |title=Alfa Romeo—Tutte le vetture dal 1910—All cars from 1910 |year=1978 |publisher=Emmeti Grafica editrice |location=[[Milan]] |edition=3rd }} {{refend}}
==External links== * {{Commons category-inline}} * [https://www.museoalfaromeo.com/en-us/collezione/Pages/A-L-F-A--24-HP.aspx ALFA 24 HP page on the Museo Storico Alfa Romeo website]
{{Alfa Romeo Pre War Timeline}} {{Alfa Romeo}}
[[Category:Alfa Romeo vehicles|24andnbsp;HP]] [[Category:First car made by manufacturer]] [[Category:Cars introduced in 1910]] [[Category:Brass Era vehicles]]