Alfa Romeo Giulia GTV Coupe

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Alfa Romeo

Alfa Romeo Giulia GTV 105/115 Series Coupe

 1965 - 1968
Country:
Italy
Engine:
Inline 4 DOHC
Capacity:
1,570 c.c
Power:
109 bhp (at 6,000 rpm)
Transmission:
4 spd. man
Top Speed:
112 mph
Number Built:
n/a
Collectability:
3 star
To understand the significance of the Giulietta and Giulia models to Alfa Romeo, you only need to look at the production history of the firm. In the pre-war era, their best years of production, 1927 saw 768 cars roll out into the Via Triano, 309 6C 1750 Turismos, 372 6C twin-cam Gran Turismos and 87 bare chassis.

Not until the introduction of the Type 1900 four-cylinder in 1950 was the 1,000 cars per annum target achieved. The year 1954 saw the introduction of the Giulietta and Giulia series, the car which really put Alfa Romeo on the map with production rising to a record 35,741 units of this one model in 1961.

The original 74 x 75 mm, 1,290 c.c. twin ohc Giulietta and the 78 x 82 mm, 1,570 c.c. Giulia units were productionized to the extent that they could be used economically even in Romeo delivery trucks. This was the first Alfa engine, apart from racing units, to have a light alloy block and wet liners and it was also the first to have bucket tappets adjusted with thimbles. Previous Alfa-Romeo overhead camshaft engines used the Hispano type of threaded valve stem and mushroom tappet.

The Giulia Sprint GT Veloce was very similar to the original Giulia Sprint GT. It featured minor modifications to the engine, providing just 3 bhp more power, but significantly improved torque. The cylinder block was a simple open-deck casting with the minimum of blind coring, only the cylinder head water take off along the side of the block being cored. The separate cast-iron cylinder liners were spigoted for approximately 30 per cent of their length into bosses cast in the floor of the water jacket and sealed with rings. The main machining operations were simply to mill the top, bottom and end faces of the block and to bore the cylinder spigots and the main bearings, very speedy operations in light alloy.

To make up for the lack of torsional strength in the water jacket, which was virtually an open-topped box, the crankcase was extended below the crankshaft centreline and was stiffened by running the main bearing webs down to the sump flange. The deeply ribbed cast aluminum sump-magnesium in the GTA imparted further strength; it was very short fore and aft to clear the front suspension sub-frame and considerably wider than the engine to present maximum area to the air stream.

The 10 equally spaced cylinder head studs were tapped into bosses formed in the floor of the water jacket in line with the bearing webs, making a direct stress line between the cylinder heads and the main bearing caps. An asbestos composition cylinder head gasket with metal fire-joint inserts was used with Neoprene rings at the oilway joints.

With hemispherical combustion chambers and valves inclined at an angle of 80 degrees, the cylinder head layout was somewhat out of style by the thinking of the time, which tended towards narrow valve angles and small diameter ports. However, the latest GTV production engines developed 109 bhp at 6,000 rpm and 116 Ib.ft of torque at 3.000 rpm. The head was also designed for ease of production with both cambox faces on a single plane so that the top and bottom faces could be machined together.

The chilled iron camshafts were each supported on five bearings and in common with the bucket tappets ran directly in the cylinder head. Valve clearances were set by selecting the thickness of the thimbles betweenthe valve stems and the tappets. As a further example of rationalization on both the Giulia Super and GTV engines the valve throat sizes were identical, 35 mm inlet and 31 mm exhaust diameters being used. The valve timing was also the same, the extra power of the GTV being obtained by carburetors with larger chokes. The GTA had a special large port head with 40.5 mm inlet and 36.5 mm exhaust valve throats.

The camshafts were driven by a two-run duplex roller chain system, although the crankshaft and half-time sprockets worked on such close centres that a gear drive could have been used. Chain drive was chosen on the grounds that it was more economical and quieter than gears. The upper chain run was tensioned by a spring loaded jockey pulley and Vernier adjustment for the valve timing was provided in the attachment of the camshaft sprockets.

The oil pump and distributor diagonal shaft was driven by a skew gear keyed to the nose of the crankshaft and the fuel pump mounted low down on the right hand side of the timing case was actuated by a cam on a separate horizontal spindle driven by a skew gear machined on the end of the half-time gear shaft. The only change in crankshaft dimensions between the original 1,290 c.c, 80 bhp Giulietta engine and the 1,570 c.c, 109 bhp Giulia GTV was an increase in main bearing diameter of 5 mm. The respective crankpin and main bearing diameters were now 50 mm and 59 mm, which with the 82 mm crankthrow gave a good journal overlap.

The compact dimensionsof the engine and the short sturdy crankshaft were made possible by availability in 1953 of Vanderveli VP2 copper-Iead-indium bearings. The crank itself was nickel-steel forging with nitrided and ground journals. The light alloy bearing caps were retained by studs and located with tubular dowels. Forged steel connecting rods had large diameter floating gudgeon pins.

The Giulia GTV's Transmission and Competition Model



The gearbox was conventional with helical constant-mesh gears and Warner synchromesh. A 1955 modification from steering column to floor shift necessitated a new rear extension for the remote control so provision was made for a fifth speed which first appeared on the 1,500c.c. type 750 Competition model, of which only two were built. Drive to the live rear axle was through a divided propellor shaft with a rubber mounted intermediate bearing. The composite axle was made by Alfa Romeo with a light alloy centrepiece and steel side tubes, a small finned sump being provided in the centre section for cooling purposes.

Body and Chassis



The unitary construction bodies had the floor, scuttle, engine compartment and luggage floor stresses so that they could be offered to specialist body builders as a self-supporting unit. Thus the passenger compartment floor was built as a perimeter frame with box section side members which were independent of the body silis and with the front and back edges of the seats formed as box members. An inverted top hat section under the front seats acted as a third cross member, and the scuttle and gearbox housing formed the front edge of the perimeter. The engine compartment sides were doubled for the lower 12'in. of their depth to form very deep boxed side members feeding loads into the scuttle.

Front Suspension



Great care has I;jeen taken in the design of the front suspension to ensure accurate. wheel location together with long life joints. Horizontal compliance-controlled fore and aft free movement of the front wheels to reduce road noise was also built into the upper wishbones. The joints of the lower wishbones, which were assembled from two steel forgings, had the minimum amount of free movement as lateral play could not be tolerated in the lower triangle. The joints used throughout were an interesting combination of solid polyurethane impregnated with lubricant as a wearing surface and a thin nylon insert to provide location.

The horizontal compliance in the upper wishbone - which was built up from a transverse link and trailing radius arm - was by means of a special slotted rubber bush with soft rubber inserts which connected the two. There were large diameter low-rate coil springs and Girling gas filled telescopic dampers. Front roll stiffness was assisted by a 0.53in. dia. anti-roll bar. Steering was by an hour-glass and worm system mounted on the engine bulkhead, in conjunction with a three-piece track rod. This gave ideal geometry with the minimum of feed-back.

When the Giulietta was in the prototype stage, cars were set up for varying degrees of understeer and oversteer and given to notable racing drivers to test on the road. The general opinion was that the most relaxing and fastest characteristic was a very slight degree of understee, after which all Giuliettas and Giulias were built this way. Rear axle location was by lower trailing arms which acted as spring levers and single upper
trunnion-supported trailing arm connected through a rubber bush to the top of the differential casing. This provided side location and also acted as a torque reaction member.

ATE disc brakes, 10.25in. dia. were fitted to all four wheels, pedal pressures being assisted by a Lockheed vacuum servo. With a swept area of 368sq. in. they were fulIy up to the performance of all three models. The mechanical handbrake operated small drum brakes built into the centres of the rear discs.

The Giulia and the Giulietta demonstrated that there was a large market for a small, high-quality GT cars, the GTV forming 40 per cent of total Giulia production which ran at around 1,000 vehicles per week during the life of the Coupe. The performance combined with the beautiful Bertone body ensured the Giuletta would be a success. A total of 14,240 Giulia Sprint GT Veloces were made before production finished.
Thoretical M.P.H. in the gears at 6,000 R.P.M.
Giulia 1300; Giulia TI Sprint Spider; TI Super Sprint Speciele. Spider Veloce, TZ; Sprint GT Giulia GTC; Giulia Super; Giulia GTA
 
Gear
Box
Ratio
GTC
GTV
4.55
GTC
GTV
4,10

GTV
5.12
Gear
Box
Ratio

GTA
4.55

GTV
4.10
1
1:3.30
28.2

31.7
25.2
1.254
36.0
40.1
2
1.99

47.2
52.5
42.0
1.70
54.1
59.5
3
1.35

69.6
77.4
61.8
1.26
72.7
80.8
4
1.00

93.7
104.5
83.3
1.00
91.3
102.0
5
0.79

118.7
132.0
105.7
0.85
116.2
119.5
R
3.01

30.0
34.8
27.6
1.301
30.2
33.6
Alfa Romeo Giulia GTV Coupe

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