All models of the Alfa Romeo 105 series - Giulia, Berlina, GT Bertone and Spider 105/115 - use the same basic engine: the four-cylinder Alfa Romeo Twin Cam in light alloy with twin overhead camshafts and a crossflow cylinder head. It was offered in displacements from 1300 to 2000. As a manufacturer, supplier and spare parts specialist for classic Alfa Romeo models, Alfa-Service carries a wide range of engine components. As the engine was used across the series, many parts are comparable; with the displacement, however, parts such as pistons, liners and some gaskets change.
Alfa Romeo 105 Engine at a Glance
The Twin Cam is an all-aluminium engine with twin overhead camshafts, hemispherical combustion chambers and a crossflow cylinder head. The four displacement stages 1300 (around 1290 cc), 1600 (around 1570 cc), 1750 (around 1779 cc) and 2000 (around 1962 cc) share the basic design but differ in bore, stroke and therefore in individual components. Mixture preparation was via carburettors or, on certain versions, via fuel injection, depending on market and model.
Engine Part Types
The range is divided into the following part types:
- Cylinder head and engine block parts
- Camshafts, timing chain and valve train
- Pistons, conrods, bearings and liners (displacement-dependent)
- Gaskets and gasket sets
- Oil circuit and lubrication components
- Water pump and engine-side ancillaries
- Engine mounting and supports
Shared Across the Series or Model-Dependent
The base engine is the same across the series, so many components are comparable between the Giulia, Berlina, GT Bertone and Spider 105/115. Decisive is the displacement: 1300, 1600, 1750 and 2000 differ in pistons, liners and partly in gaskets as well as in compression. Mixture preparation (carburettor type or injection) can also differ by model and market, which is relevant for ancillaries. When selecting engine parts, displacement, model year and version should therefore be observed.
Model Families
For a model-specific selection, the following categories lead to the model families:
Twin Cam Displacements and Model Variants
The Twin Cam engine of the 105 series goes back to the four-cylinder design of the preceding Giulietta models and was developed further across the whole series. Fundamentally the same are the aluminium block, the aluminium cylinder head with twin overhead camshafts, the drive via a timing chain and the valve train with bucket tappets. With the displacement, mainly bore and stroke change, and with them the pistons, liners and individual gaskets. The four stages 1300, 1600, 1750 and 2000 thus cover a broad power range without leaving the common basic design.
In mixture preparation there are clear differences between the variants. Many models received twin carburettors, while some early versions were fitted with a single downdraught carburettor. Certain late versions, above all those intended for the US market, used fuel injection. It follows that ancillaries such as the inlet manifold and associated components differ by engine variant, while the crank assembly within one displacement stage remains largely the same. When selecting, the displacement should therefore be established first and then the type of mixture preparation.
The engine components can be divided into clear part types. These include cylinder head and engine block parts, the valve train with camshafts and timing chain, the displacement-dependent crank assembly with pistons, conrods, bearings and liners, gaskets and gasket sets, oil circuit and lubrication components, the water pump as an engine-side ancillary as well as the engine mounting with its supports. Known points of the Twin Cam are timing chain and valve train noise as well as the head gasket; corresponding parts are listed as their own groups, so the right component can be chosen specifically.
As the Giulia, Berlina, GT Bertone and Spider 105/115 use the same base engine, many parts are comparable across the series. The state of tune - for example compression, carburettor or injection - can differ, however, by model and market. For a reliable selection, displacement, model year and mixture preparation should be clarified in advance. This makes it possible to assign displacement-dependent parts such as pistons and liners just as accurately as gaskets and engine-side ancillaries.
In addition, gasket sets are often needed as complete head or engine sets matched to the respective displacement, while wear-related parts such as timing chain components, the water pump and oil circuit parts can be assigned specifically to the engine variant. Separating displacement-bound items from parts shared across the series makes it easier to put together a complete and matching package.
Related Assemblies
The following areas are also relevant:
Notes on Part Selection
Decisive are the displacement (1300, 1600, 1750, 2000), the model year and the type of mixture preparation. These determine displacement-dependent parts such as pistons and liners as well as individual gaskets and ancillaries. Checking against the specific vehicle and engine variant is recommended.
FAQ
Which engine do the 105-series models have?
They all use the four-cylinder Alfa Romeo Twin Cam in light alloy with twin overhead camshafts, in displacements from 1300 to 2000.
Are engine parts usable across the series?
Many parts are comparable because the same base engine was used. Displacement-dependent parts such as pistons and liners do differ, however.
Which displacements are there?
1300, 1600, 1750 and 2000. They share the basic design but differ in individual components.
Which engine components are available?
Among others, cylinder head and engine block parts, valve train, pistons, gaskets and parts for lubrication and engine mounting.
Is Alfa-Service a workshop?
No. Alfa-Service is a manufacturer, supplier and spare parts specialist for classic Alfa Romeo models and does not carry out repairs.
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