Alfa Romeo Spider/GTV

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Advanced when new, there’s still a lot you can do to further forward these stylish and sophisticated Alfas as we now reveal

With their all alloy engine fed by overhead (twin) cams, proper dual twin choke carbs, disc brakes, slick five-speed transmissions… Alfa’s 105 Giulia, GTV and Spider ranges sported all the ingredients that would have done a Ferrari proud.

Yet as good as these cars still perform on today’s black top, there’s a heck of a lot you can do to make these Latin lovelies better for today’s roads as well as some mild competition work.

Before you start

Rust is the biggest worry on all. Penny to a pound remedial work will have been carried out. Wheelarches, floor, wings and the front crossmember are vital check points and it’s best to take a magnet round the whole bottom 10 inches of the car. US sourced Spiders, although usually rot free, ride on softer suspensions and usually have iffy, de toxed mechanical fuel injection and considerably less powerful engines.

Mechanically (apart from minor head gasket troubles) the cars are fairly robust and there’s great scope for parts interchangeability. You can re-sleeve engine with new pistons and cylinder liners for just £400 and it’s certainly wise if you intend serious tuning.

Italian electrics… what can you add – except they can be made pretty reliable as it’s generally poor earths that are the real culprits!

There’s no shortage of affordable Alfas around so don’t rush in and buy the first one you see. The boxy saloons are the cheapest starting at £6000 for a decent one, Series 2 Spiders are up to £15,000 but 1980’s models the least valued, starting from £4000 for a goer and little more than £8000 for a peach.

The GTV is the most expensive and fashionable at the moment – the older cars are the most valued of course, up to £40,000 for a top one!

Hotting one up

Advanced for its day, this twin cam engine is already tuned to a fair level and certainly the standard Weber or Dellorto carbs can withstand a fair chunk of further tweaking just by dint easy re-choking and re-jetting complemented by modern performance filters. For a mild tune, the first step is a session on a rolling road to optimise the carbs and ignition (fit an electronic set up first: a 123 distributor costs from £250 with programmable alternatives at £295) followed by a tubular 4-2-1 manifold to liberate some eight bhp; specialist Classic Alfa has a GTA-style one (best for up to smaller units but fine for 1750/2000 models says the company) at £265, its own sports harder core type at £465 and an exhaust system to suit at around £650.

Next step are a change of camshafts, suggests Classic Alfa (made by Italian Colombo & Bariani). Costing £400 but a nice cheap tweak on the smaller 1.3 and 1.6 units is to simply fit the pokier cams found in the 2000 engine. In contrast, Classic Alfa has its own range of cams for road, race or rally use. Be careful who hots up the heads because it’s easy to mess up the already decent porting here. Again, Classic Alfa has its own dedicated head and cam kit which literates a massive claimed 40bhp power hike!

The logical route with 1300/1600 cars is to slip in a 1750 or 2000 engine which, as it’s a nut and bolt job, may already have been done. You can also use the modern Twin Spark to great effect although there’s numerous hidden mods needed (see box out on next page for fuller details).

The 1600 and 2000 engines can be enlarged easily; oversize Cosworth pistons to go with new liners can yield an extra 30bhp and really improve the low end torque, it is said.

Strengthening plates that bolts to main bearing caps cost £85 and improves crank torsional rigidity plus reduces oil drag on the rotating crankshaft. Don’t ignore this as 105 blocks putting more than 140bhp can twist and cause bearing failure. This plate also reduces twist and helps prevent oil starvation on 2000 units adds Classic Alfa.

Handling the power

When it comes to transmissions, these Alfas already come with five-speeds as standard albeit geared for acceleration rather than cruising. An even closer set of cogs are available but they are primarily geared (geedit-ed) for competition. A cheaper alternative is to simply fit a ’box from a 1300 as it has a shorter top gear ratio (if you can find one, that is). If you can also hunt down a 2000 Berlina saloon, nick its rear axle because it’s a limited slip affair and with a rare 4.3:1 rear axle ratio for best pulling power if a lousy cruising gait.

Some of the best handlers in their day (although there are differences in designs between the Spider and 105; the former’s chassis was based on the earlier open-top Giulietta and Giulia), there’s more than enough scope to make these rapid Romeos keep up with most moderns – but be careful how you do it, experts warn.

For instance, Classic Alfa doesn’t recommend hard ‘polybushing’ the rear trailing arms as they are supposed to have some natural ‘give’ so instead advises using harder rubber types unless it’s for track use. On the other hand, the company suggests Superflex elsewhere coupled to a variety of suspension ‘shox’ and spring kits: £395 for the ‘Classic’ and £625 when equipped with Koni or Bilstein dampers.

Harder and adjustable damping along with better springs and a thicker (29mm) front anti-roll bar are the best mods. You can even opt for adjustable top mounts and spacers to alter the camber settings but this isn’t really needed for just fast road use.

Talking of speed, how fast do you want to stop? As standard, there’s discs all round anyway and providing the system is in good shape, perhaps just harder sports pads will suffice for road use. You can, for some £800, fit Classic Alfa’s complete braking kit which consists of more powerful four-pot calipers, discs – the works. But if you have a 1300 or 1600 only mildly modded, then using brakes from the Alfa 75 is a cheaper and as good upgrade.

Most later cars featured twin servos – it’s quirky but quite okay but it’s better to fit a normal single set up says many Alfa pundits who add some folks who fit the big brake kit ditch servo assistance entirely.

There’s no rack and pinion conversion known but late LHD Spiders came with power steering which will fit other LHD models after a bit of graft or go electric instead; S4 cars featured PAS anyway.

Finally, tyres. As with many other classics, going over-wide sounds logical but hinders rather than helps that dream drive. A 185/70 is quite ample and certainly no fatter than 195/65 – please!When it comes to transmissions, these Alfas already come with five-speeds as standard albeit geared for acceleration rather than cruising. An even closer set of cogs are available but they are primarily geared (geedit-ed) for competition. A cheaper alternative is to simply fit a ’box from a 1300 as it has a shorter top gear ratio (if you can find one, that is). If you can also hunt down a 2000 Berlina saloon, nick its rear axle because it’s a limited slip affair and with a rare 4.3:1 rear axle ratio for best pulling power if a lousy cruising gait.

Some of the best handlers in their day (although there are differences in designs between the Spider and 105; the former’s chassis was based on the earlier open-top Giulietta and Giulia), there’s more than enough scope to make these rapid Romeos keep up with most moderns – but be careful how you do it, experts warn.

For instance, Classic Alfa doesn’t recommend hard ‘polybushing’ the rear trailing arms as they are supposed to have some natural ‘give’ so instead advises using harder rubber types unless it’s for track use. On the other hand, the company suggests Superflex elsewhere coupled to a variety of suspension ‘shox’ and spring kits: £395 for the ‘Classic’ and £625 when equipped with Koni or Bilstein dampers.

Harder and adjustable damping along with better springs and a thicker (29mm) front anti-roll bar are the best mods. You can even opt for adjustable top mounts and spacers to alter the camber settings but this isn’t really needed for just fast road use.

Talking of speed, how fast do you want to stop? As standard, there’s discs all round anyway and providing the system is in good shape, perhaps just harder sports pads will suffice for road use. You can, for some £800, fit Classic Alfa’s complete braking kit which consists of more powerful four-pot calipers, discs – the works. But if you have a 1300 or 1600 only mildly modded, then using brakes from the Alfa 75 is a cheaper and as good upgrade.

Most later cars featured twin servos – it’s quirky but quite okay but it’s better to fit a normal single set up says many Alfa pundits who add some folks who fit the big brake kit ditch servo assistance entirely.

There’s no rack and pinion conversion known but late LHD Spiders came with power steering which will fit other LHD models after a bit of graft or go electric instead; S4 cars featured PAS anyway.

Finally, tyres. As with many other classics, going over-wide sounds logical but hinders rather than helps that dream drive. A 185/70 is quite ample and certainly no fatter than 195/65 – please!

Fitting a twin spark

If you don’t mind a bit of work, you can slip in the latter, much perkier ‘Twin Spark’ engine (featuring two plugs per cylinder bank) as found in the 75 saloon, for instance. It’s not a bad idea because apart from the engine being basically the same, they are inexpensive to obtain and the entire exercise is normally cheaper than rebuilding the original! That said, engines that are transversely-mounted (155,164 etc) are a lot harder to install and perhaps it’s not worth the hassle, so seek the advice of experts who have done it. Some ’75’ engines didn’t feature a spigot bearing due to the rear location of the transmission and so you may need a machine shop to drill a hole in the crankshaft if it’s missing but that’s the only main hassle.

This particular unit drops straight in otherwise – it’s claimed – if you employ the 2000 clutch, flywheel and starter motor. The 75 featured a Bosch fuel injection which is worth saving and using as it comes with a separate loom that’s fairly straightforward to mate although the fuel system needs modding. Wilts-based EB Spares (01373 823856) is king of this conversion and makes bespoke parts such as a fabricated exhaust manifold (under £300). As we stressed earlier, get expert advice beforehand.