The Alfa Romeo twin cam engine ("bialbero", with double overhead camshafts) powers the Giulia, GT Bertone and Spider of the 105/115 family in 1300, 1600, 1750 and 2000 form. Well maintained, it copes happily with regular use. This guide lists the parts to have on hand for routine servicing and suggests indicative intervals, deliberately cautious for cars that cover few miles or are used irregularly.
Engine sizes covered
- 1300: 1,290 cc;
- 1600: 1,570 cc;
- 1750: 1,779 cc;
- 2000: 1,962 cc.
The layout is common to all: aluminium block with wet liners, aluminium cylinder head, two chain-driven camshafts. Fuelling varies by version: twin-choke sidedraught carburettors on most European cars, SPICA mechanical fuel injection on some US-market versions, and electronic injection on the last Spiders. Always state the engine size, version and year when ordering.
Timing: a chain, not a belt
On the twin cam of this period, the camshafts are driven by a duplex chain with a tensioner and guides. There is no cambelt to replace at set intervals. The only belt to keep an eye on is the one driving the alternator and water pump.
- Chain noise at idle or on start-up warrants a check of the tension, following the workshop manual procedure for your version.
- The chain, tensioner and guides are replaced during a top-end rebuild or when wear requires it.
Parts to have on hand for routine servicing
- engine oil and oil filter;
- air filter and fuel filter;
- spark plugs and, depending on the ignition, points and condenser;
- alternator and water pump belt;
- cam cover gasket;
- coolant and, if needed, thermostat and hoses.
For bigger jobs (cylinder head, timing), a top-end gasket set means you will not be held up by a missing gasket.
Indicative intervals
The intervals below are cautious guidelines for a regularly maintained classic car. They do not replace the original service book or the actual condition of the engine.
| Task | Indicative interval |
|---|---|
| Oil and oil filter change | Every 5,000 km (3,000 miles) or once a year |
| Spark plug check | At every oil change; replace every 10,000 km (6,000 miles) |
| Points, condenser, ignition timing | Check at every oil change |
| Air filter | Once a year or every 10,000 km (6,000 miles) |
| Fuel filter | Once a year |
| Alternator and water pump belt | Check at every oil change, replace if cracked |
| Coolant | Every two years |
| Brake fluid | Every two years |
| Valve clearances | Check every 7,500 km (4,500 miles), or if noisy |
| Carburettor balancing and adjustment | Annual check, after setting the ignition |
A car that covers few miles should have its oil changed on a time basis rather than mileage: an oil change before winter storage is recommended.
Adjustments
- Valve clearances: these are set with calibrated shims. Measure with the engine cold; changing shims means removing the camshafts. Values depend on the version: refer to the workshop manual.
- Ignition: on a points ignition, the points gap and ignition timing are checked together. Electronic ignition does away with points wear but not with checking the timing.
- Carburation: balancing the carburettors and setting the idle come last, with the ignition set and the engine warm.
Oil and lubricants
These engines were designed for mineral oils. The choice of grade depends on the engine's condition, how it is used and the season; a multigrade oil suitable for classic engines is right in most cases. Ask us for advice if the engine has been rebuilt or is using oil.
Where to find the parts
- GT Bertone servicing, filters and oils;
- Giulia / Berlina filters and Spider filters;
- HT leads and spark plugs and points ignition;
- Timing and gasket sets.
Most of these parts are shared by the Giulia, GT Bertone and Spider of the same engine size: the product page lists the applications.
The Ma Petite Italienne workshop
Our workshop in Nazelles-Négron (Indre-et-Loire, France) carries out routine servicing, diagnosis and rebuilds of twin cam engines: valve clearance adjustment, ignition and carburettor tuning, timing chain replacement and full rebuilds. We welcome cars from all over France and abroad. To book a service or request a quote, contact us.