Alfa Romeo
6C 1750 Gran Sport Testa Fissa (works)

Why it matters

The Testa Fissa was the most highly developed form of the 6C 1750 Gran Sport. Its engine had block and head cast as one piece, which removed the head-sealing problems that high pressures and long races caused on detachable-head racing engines, and it produced about 102 horsepower. It was built mainly for racing and the works and Scuderia Ferrari used the type, with drivers such as Campari, Nuvolari and Varzi.

How rare is it?

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

Each kind of rarity is rated separately and never combined.

Photos

Exterior, interior and detail photos with their licences.

• Alfa Romeo 6C 1750 Gran Sport Testa Fissa (works) (Wikimedia Commons: Alfa Romeo 6C 1750 Gran Sport Testa Fissa in the Louwman Museum)
  Photo: Alf van Beem · Public domain
• Alfa Romeo 6C 1750 Gran Sport Testa Fissa (works) (Wikimedia Commons: Alfa Romeo 6C 1750 Gran Sport Testa Fissa in the Louwman Museum)
  Photo: Alf van Beem · Public domain
• Alfa Romeo 6C 1750 Gran Sport Testa Fissa (works) (Wikimedia Commons: Alfa Romeo 6C 1750 Gran Sport Testa Fissa in the Louwman Museum)
  Photo: Alf van Beem · Public domain
• Alfa Romeo 6C 1750 Gran Sport Testa Fissa (works) (Wikimedia Commons: Alfa Romeo 6C 1750 Gran Sport Testa Fissa in the Louwman Museum)
  Photo: Alf van Beem · Public domain

Production

Every figure says what it counts.

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

History

Alfa Romeo introduced its Jano-designed 1752 cc six-cylinder cars in 1929, and the Testa Fissa was a fourth, ultimate specification of the 6C 1750 built in very small numbers. The Museo Storico lists six Testa Fissa cars, whereas RM Sotheby's says twelve are believed to have been constructed; a Christie's lot text says about six 1500 cc cars received the engine in 1929/30.

For the Tourist Trophy of 23 August 1930 the British Alfa Romeo importer obtained three strengthened chassis with works 102 bhp Testa Fissa engines and had four-seater bodies fitted to meet the race regulations. Nuvolari, Varzi and Campari finished first, second and third, Nuvolari winning at an average of 70.88 mph. RM Sotheby's states that the factory then kept the Testa Fissa engine of Nuvolari's car and replaced it with a standard detachable-head engine before the car was sold.

Technical specifications

Engine

Transmission & drivetrain

Chassis, body & dimensions

Performance

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

Identification guide

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

The defining feature is the one-piece cast block and head with no detachable cylinder head. RM Sotheby's calls the works unit an eight-bearing engine, against the five-bearing detachable-head engine fitted to the T.T. car after the race, and quotes about 102 hp for the Testa Fissa. Because works engines were retained, swapped and later rebuilt (the T.T. car, chassis and engine number 8513089, had a new Testa Fissa head cast in its 2011 rebuild), the engine's documented identity needs checking. Museum data for the type: 2745 mm wheelbase, 840 kg, 1752 cc (65 x 88 mm).

Sources

Each number links to the exact facts it supports.

1. 1
   Museo Storico Alfa Romeo, collection: 6C 1750 Gran Sport Level A Museo Storico Alfa Romeo (Arese)

   • 6 (testa fissa)
   • 6 cilindri in linea, monoblocco e testa fissa in ghisa (Dettagli vettura)
   • 6 cilindri in linea (Dettagli vettura)
   • 1752 cc (65x88 mm) (Dettagli vettura)
   • 2 valvole per cilindro, 2 alberi a camme in testa ... alberino e coppie coniche (Dettagli vettura)
   • carburatore doppio corpo e compressore (Dettagli vettura)
   • Alimentazione carburatore doppio corpo e compressore (Dettagli vettura)
   • 102 CV a 5000 giri/min. (Dettagli vettura)
   • 4 marce + RM (Dettagli vettura)
   • Trazione posteriore (Dettagli vettura)
   • Longheroni e traverse in lamiera di acciaio (Dettagli vettura)
   • Anteriore: assale rigido, balestre longitudinali semiellittiche (Dettagli vettura)
   • Posteriore: assale rigido, balestre longitudinali semiellittiche (Dettagli vettura)
   • Freni: Posteriori a tamburo, meccanici (Dettagli vettura)
   • Carrozzeria Spider Corsa (Dettagli vettura)
   • Passo: 2745 mm, lunghezza: 3652 mm (Dettagli vettura)
   • Peso 840 kg (Dettagli vettura)
   • Massima velocità 170 km/h (Dettagli vettura)

   Accessed 2026-11-12
2. 2
   Alfa Romeo 6C 1750 Gran Sport – Heritage Hub Italy (Stellantis Heritage) Level A

   • 6 Testa Fissa versions among the 213 4th/5th-series Gran Sport made 1930–1932 ('including only six Testa Fissa versions')

   Accessed 2026-11-12