Rare Car Archive

Makes › Alfa Romeo Italy › 8C › 8C 2300 Castagna Cabriolet · Coachbuilt · 1931–1934 Ultra Rare

Alfa Romeo
8C 2300 Castagna Cabriolet

Castagna-bodied cabriolets on 8C 2300 long chassis

Body: Castagna
IDENTIFICATION CARD · ALFA ROMEO 8C 2300 CASTAGNA CABRIOLET 1931–1934
No licensed photograph yet. Photographs are published only when their licence permits it.
8BuiltIndependently researched
0Chassis documentedin this archive
?SurvivingNot yet verified
Contents
  1. 01Overview
  2. 02Production & history
  3. 03Specifications
  4. 04Colours & options
  5. 05Individual cars
  6. 06Reference

01Overview

At a glance

Built
8 Built
Years
1931–1934
Engine
Front, longitudinal, inline eight-cylinder; two four-cylinder blocks (biblock) with light-alloy head · 2,336 cc / 2.3 LFactory: 2,336 cc
Power
114 kW / 155 PSFactory: 155 PS
Top speed
Not yet verified
Designer
Vittorio Jano (chassis and engine); body by Carrozzeria Castagna
In this archive
Not yet verified
Surviving
Not yet verified

Sources and any conflicting figures are in the sections below.

Why it matters

The Castagna cabriolet is one of the open coachbuilt bodies on the 8C 2300 chassis, which Vittorio Jano engineered around a twin-cam supercharged eight-cylinder engine and which brought Alfa Romeo four Le Mans wins between 1931 and 1934.

How rare is it?

Six separate kinds of rarity – never combined into one number.

Model rarityUltra Rare 8 · Built1
Specification rarityNot yet assessed
Colour rarityNot yet assessed
Individual rarityNot yet assessed
Historical rarityNot yet assessed
Survival rarityNot yet assessed

Each kind of rarity is rated separately and never combined.

02Production & history

Production

Every figure says what it counts.

What is countedFigureBasisStatus
Total model productionCastagna-bodied long-chassis 8C 2300s ('just eight of these cars were ever built'); note the same page's spec field says 'Units built: 2', apparently for one body variant 81 Factory production Independently researched

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

History

The cached Gooding lot describes a 1933 third-series 8C 2300 long chassis, number 2311214 with the same engine number, fitted with open coachwork by Castagna of Milan. It was offered in 2009 as a drop-head coupe and in 2023 as a cabriolet. Gooding says it had only four owners since 1942 and received a restoration by Paul Russell and Company that won First in Class at the 2008 Pebble Beach Concours.

Variants

How each version differs from the standard 8C 2300 Castagna Cabriolet.

No variants documented yet. Have a source? Contribute it.

03Specifications

Technical specifications

Engine

Engine familyNot yet verified
Engine codeNot yet verified
LayoutFront, longitudinal, inline eight-cylinder; two four-cylinder blocks (biblock) with light-alloy head2
Cylinders82
Displacement 2,336 cc / 2.3 LFactory: 2,336 cc2Base 8C 2300 figure from the museum page, which shows a specific museum car, not necessarily this body.
Bore 65 mmFactory: 65 mm2Base 8C 2300 figure from the museum page, which shows a specific museum car, not necessarily this body.
Stroke 88 mmFactory: 88 mm2Base 8C 2300 figure from the museum page, which shows a specific museum car, not necessarily this body.
Compression ratioNot yet verified
Valvetrain2 valves per cylinder, 2 overhead camshafts driven by gears2
Fuel systemSingle Memini carburettor3 Independently researched
InductionPositive-displacement (lobed) supercharger2
Power 114 kW / 155 PSFactory: 155 PS2Rating: manufacturerBase 8C 2300 figure (museum writes CV). Gooding lists 150 BHP at 4,800 rpm for this car (2023, S2) and 152 BHP at 5,000 rpm (2009, S3).
Power at 5,200 rpm2
TorqueNot yet verified

Transmission & drivetrain

GearboxNot yet verified
Gears43 Independently researched
Driven wheelsNot yet verified

Chassis, body & dimensions

ChassisNot yet verified
Front suspensionSolid axle, semi-elliptic leaf springs, shock absorbers3 Independently researched
Rear suspensionLive axle, semi-elliptic leaf springs, shock absorbers3 Independently researched
BrakesMechanical drum brakes on all four wheels3 Independently researched
SteeringNot yet verified
Body constructionNot yet verified
WheelbaseNot yet verified
LengthNot yet verified
WidthNot yet verified
HeightNot yet verified
Front trackNot yet verified
Rear trackNot yet verified
Kerb weightNot yet verified
Dry weightNot yet verified

Performance

Maximum speedNot yet verified
0–100 km/hNot yet verified
Fuel tankNot yet verified

“Not yet verified” means no source has been checked for that value yet. Nothing is estimated to fill a gap.

04Colours & options

Factory colours & interiors

Original paint and trim, with the number of cars in each where a source gives it.

Not yet documented. Have a source? Contribute it.

Factory options & codes

Codes are shown exactly as written by the manufacturer.

Not yet documented. Have a source? Contribute it.

05Individual cars

Chassis register

Every documented car, with its colours, history and where it is now. Open a row for the full record. Known chassis are not automatically authenticated originals.

Not yet documented. Have a source? Contribute it.

Competition history

Every race result of the individual cars, in date order. Click a chassis number to open its full record in the register.

Not yet documented. Have a source? Contribute it.

Auction & sale history

Documented public sales of the individual cars. Click a chassis number to open its full record in the register.

Not yet documented. Have a source? Contribute it.

See one in person

Museums where an example of this car can be seen.

No example is documented on public display yet. Have a source? Contribute it.

06Reference

Identification guide

How to tell an original from a replica or later conversion.

Gooding describes the car as a highly developed third-series 2.3 with matching chassis and engine numbers (both 2311214), a gear-driven Roots supercharger, a single Memini carburettor, rod-operated mechanical drum brakes, rigid axles on semi-elliptic leaf springs and Siata friction shock absorbers. It is documented in Simon Moore's books on the 8C 2300.

Sources

Each number links to the exact facts it supports.

  1. 1
    Carrozzieri Italiani – Alfa Romeo 8C 2300 Drophead Coupé Castagna Level C
    • 8 Castagna-bodied long-chassis 8C 2300s ('just eight of these cars were ever built'); note the same page's spec field says 'Units built: 2', apparently for one body variant
    Accessed 2026-11-12
  2. 2
    Museo Storico Alfa Romeo, collection: 8C 2300 Corto "Mille Miglia" Level A Museo Storico Alfa Romeo (Arese)
    • 8 cilindri in linea, biblocco e testa in lega leggera (Dettagli vettura)
    • 8 cilindri in linea (Dettagli vettura)
    • 2336 cc (65x88 mm) (Dettagli vettura)
    • 2 alberi a camme in testa con comando ad ingranaggi (Dettagli vettura)
    • compressore volumetrico a lobi (Dettagli vettura)
    • 155 CV a 5200 giri/min. (Dettagli vettura)
    Accessed 2026-11-12
  3. 3
    1933 Alfa Romeo 8C 2300 Cabriolet by Castagna, Pebble Beach 2023 Level C Gooding & Company
    • Single Memini Carburetor (Technical Specs)
    • 4-Speed Manual Gearbox (Technical Specs)
    • Front Solid Axle with Semi-Elliptical Leaf Springs and Shock Absorbers (Technical Specs)
    • Rear Live Axle with Semi-Elliptical Leaf Springs and Shock Absorbers (Technical Specs)
    • 4-Wheel Mechanical Drum Brakes (Technical Specs)
    Accessed 2026-11-12

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