Saturday, November 2, 2024
Cleaning and Refinishing GTV6 Engine Parts
Wednesday, July 31, 2024
1981 Alfa GTV6 Dealer Press Release Intro
1981 Alfa Romeo GTV6 Brochure
Saturday, February 18, 2023
Alfa Romeo GTV6 Transmission Ratios
The Alfa Romeo GTV6 transmission gear ratios have been revised a few times during its production life. Using official factory resource materials, here's a look at the various gear ratios used. Before we do, like many things that concern the GTV6, production changes overlap model years. For example, my car is a 1982 model year but has the 1981 transmission ratios. So don't be surprised if a 1984 car has 1983 gear ratios, etc. Typical Alfa.
When the car debuted in Europe in 1980, the ratios were as follows.
Alfa Romeo GTV6 Transmission Ratios (European and Early US Cars)
ALFA GTV6 EURO AND EARLY US TRANSMISSION GEAR RATIOS
Final Drive: 4.10:1
(gear ratio / overall ger ratio)
1st: 3.50:1 / 14.350:1
2nd: 1.956:1 / 8.0196:1
3rd: 1.345:1 / 5.5145:1
4th: 1.026:1 / 4.2066:1
5th: 0.78:1 / / 3.198:1
REV. 3.000 1 / 12.3000
European and Early US Spec Alfa Romeo GTV6 Speeds in Gear*
1st @1000rpm 4.8mph (7.803kmh) @6300rpm 30.55 mph (49.16 kmh)
2nd @1000rpm 8.67 mph (13.964 kmh) @63000rpm 54.66 mph (87.97 kmh)
3rd @1000rpm 12.63 mph (20.321kmh) @63000rpm 79.55 mph (128.02 kmh)
4th @1000rpm 16.55 mph (26.642 kmh) @6300rpm 104.29 mph (167.85 kmh)
5th @1000rpm 21.78 mph (35.053 kmh) @6300rpm 137.22 mph (220.83 kmh)
RPM @ 60 mph in 5th gear: 2755 rpm
These were the same ratios used in North America when the GTV6 hit our shores in 1981. Some early 1982 GTV6 models also had these ratios until they were replaced by the noticeably taller ones below.
Alfa Romeo GTV6 Transmission Ratios (1982-1983 US Spec)
1982-1983 ALFA GTV6 TRANSMISSION GEAR RATIOS
Final Drive: 3.42:1
1st 3.500: 1 / 11.958:1
2nd 1.956: 1 / 6.683: 1
3rd 1.258: 1 /4.298 1
4th 0.946: 1 / 3.232: 1
5th 0.780: 1 / 2.665: 1
REV. 3.000 1 / 10.249: 1
1982-83 US Spec Alfa Romeo GTV6 Speeds in Gear**
1st @1000rpm 5.82 mph (9.37 kmh) @6300rpm 36.68 mph (59.03 kmh)
2nd @1000rpm 10.41 mph (16.76 kmh) @63000rpm 65.61 mph (105.59 kmh)
3rd @1000rpm 16.20 mph (26.07 kmh) @63000rpm 102.06 mph (164.24 kmh)
4th @1000rpm 21.54 mph (34.66 kmh) @6300rpm 135.68 mph (218.36 kmh)
5th @1000rpm 26.10 mph (42.00 kmh) @6300rpm 164.41 mph (264.60 kmh)
RPM @ 60 mph in 5th gear: 2299 rpm
Some feel that these taller ratios took away the "hot-rod" feel of the earlier car. However, the lower rpms at highway speed were welcomed by many who spent a lot of time on the highway. First gear also became more useful. Zero to sixty times were also improved by eliminating the shift out of second gear before sixty miles per hour were reached.
Alfa Romeo GTV6 Transmission Ratios (1984-85 US Spec and Other Markets)
These ratios continued until the 1984 model year, when the 1982 tall gear ratios were combined with the original 4:10:1 final drive. This transmission is referred to in Alfa Romeo documentation as the "High-Geared Gearbox/Differential."
1984-1985 ALFA GTV6 TRANSMISSION GEAR RATIOS
Final Drive: 4.10:1
1st 3.500:1 / 14.350:1
2nd 1.956:1 / 8.0196:1
3rd 1.258:1 / 5.1578:1
4th 0.946:1 / 3.8786:1
5th 0.780:1 / 3.198:1
1984-85 US Spec Alfa Romeo GTV6 Speeds in Gear*
1st @1000rpm 4.84 mph (7.80 kmh) @6300rpm 30.53 mph (49.14 kmh)
2nd @1000rpm 8.67 mph (13.96 kmh) @63000rpm 54.65 mph (87.95 kmh)
3rd @1000rpm 13.50 mph (21.73 kmh) @63000rpm 85.07 mph (136.90 kmh)
4th @1000rpm 17.95 mph (28.89 kmh) @6300rpm 113.10 mph (182.01 kmh)
5th @1000rpm 21.78 mph (35.05 kmh) @6300rpm 137.21 mph (220.82 kmh)
RPM @ 60 mph in 5th gear: 2755 rpm
Note: These speeds are based on 195 60 R15 tires for comparison sake and not the TRX Metric 200/60 HR365 tires size standard on the 1985 US GTV6.
Interestingly, while most European cars I've heard of stayed with the original 1980 gear ratios, this "High-Geared Gearbox/Differential" is listed in the European Technical Inspection Manual dated from 3/1984.
1985.5 ALFA GTV6 Isostatic Gear Shift
Starting about mid-way through the 1985 model year for US cars (Chassis number 10006731 according to Alfa Romeo documentation), Alfa updated the transmission shift linkage for an improved feel. This revised shift linkage is commonly called "Isostatic ." This modification replaced the simple external shift lever at the transmission case with a series of rods and levers. The consensus at the time was that the revised shifter was smoother, easier, and had a more positive feeling than the rather clunky original shifters. However, nearly 40 years later, Isostatic shifter parts are challenging to source. Because of that, some are saying if you have a worn-out shifter, you are better off now with the old-style shifter mechanism. So much for doing the Isostatic upgrade I never got around to doing!
Update 2-21-2023
I see the Alfa Romeo European Workshop Manual showing 1985 and later European GTV6 models as having the ratios listed below. I invite our European friends to post a comment and let us know what ratios they have in their cars.
Alfa Romeo GTV6 Transmission Ratios (1986 US Spec and late 1985 European Version)
1986 ALFA GTV6 TRANSMISSION GEAR RATIOS
Final Drive: 4.10:1
1st 2.875: 1 / 11.787:1
2nd 1.720: 1 / 7.052:1
3rd 1.226 1 / 5.027:1
4th 0.946 1 / 3.879:1
5th 0.780:1 / 3.198:1
REV. 3.000 1 / 12.300:1
1986 US Spec and late 1985 European Version Alfa Romeo GTV6 Speeds in Gear*
1st @1000rpm 6.00 mph (9.646 kmh) @6300rpm 37.76 mph (60.770 kmh)
2nd @1000rpm 10.01 mph (16.123 kmh) @63000rpm 63.12 mph (101.575 kmh)
3rd @1000rpm 14.05 mph (22.620 kmh) @63000rpm 88.55 mph (142.506 kmh)
4th @1000rpm 18.21 mph (29.315 kmh) @6300rpm 114.76 mph (184.685 kmh)
5th @1000rpm 22.08 mph (35.553 kmh) @6300rpm 139.18 mph (223.984 kmh)
RPM @ 60 mph in 5th gear: 2716 rpm
Update 2-19-2023:
I have found official speeds in gear@1000 rpm and have updated the 1986 numbers. Previously they were calculated.
Let us know if you have more information to share by leaving a comment. Thanks for reading!
----------------------------------------------
Sources:
Alfa Romeo Inspection Specifications publications dated 10/1981, 2/1981, 3/1984,
Alfa Romeo GTV6 Owners Manuals: 1981 through 1986
Alfa GTV6 Spare Parts Catalog, USA edition 0060495165, 9-1989
Alfa Romeo Workshop Manual PA36090+ 9/84
*Official km/h @ 1000 RPM speeds in gear provided by factory. Converted to mph for convenience.
**Approximate speeds in gear calculated. Factory tire size value used. Rolling radius of tires, among other variables, affects speed. Speeds are rounded for convenience.
Friday, February 3, 2023
Alfa GTV6 Thermostat Replacement
Alfa Romeo GTV6 Thermostat Temperature Specs
- Initial opening: 180-185°F (81-85°C)
- Fully open: 200°F (95°C)
Alfa Romeo GTV6 Thermostat Part Number
- 60558491
Alfa Romeo GTV6 Thermostat Gasket Part Number
- 60507415 Upper Gasket
- 60777088 Lower Gasket
Alfa Romeo GTV6 Cooling System Bleed Screw Part Number
- 60506832
Alfa Romeo GTV6 Cooling System Bleed Screw Washer Part Number
- 60800596
Alfa Romeo GTV6 Cooling System Capacity
- 3.2 Gallons
- 12 Liters
A paper gasket seals the thermostat. Note the hole at 10:00 is the bleeder passage. It is important to bleed all the air out of a GTV6 cooling system if you want trouble free operation and a cool running car.
ALFA ROMEO GTV6 THERMOSTAT REMOVAL
2. Drain and coolant down below the lower edge of the thermostat housing.
3. Disconnect the upper radiator hose.
Take care not to detach the lower gasket between the thermostat intermediate spacer and lower radiator hose adapter. In case you do, that is why you order the upper and lower thermostat gaskets.
Now is an excellent time to inspect all your hoses if you haven't done that beforehand.
Spend extra attention on the two hoses attached to the thermostat intermediate spacer. This would be the time to change them.
If you decide to change anything more than the thermostat, remember to drain the cooling system down. You need to take care not to spill anti-freeze on the timing belt if you are not changing it.
ALFA ROMEO GTV6 THERMOSTAT CHECKS AND INSPECTIONS
ALFA ROMEO GTV6 THERMOSTAT INSTALLATION
ALFA ROMEO GTV6 THERMOSTAT INTERMEDIATE SPACER
REFILLING THE ALFA ROMEO GTV6 COOLING SYSTEM
- Set the heater control to max heat.
- Open the cooling system bleed screw.
- Fill the expansion tank with coolant.
- Start the engine and run it until the thermostat starts to open and coolant begins to flow from the bleed screw. Immediately tighten the bleed screw once that happens. Protect yourself - hands, face, and arms - from hot coolant, and have a heavy towel handy to absorb the leaking coolant as you open the bleed screw.
- Turn the engine off, allow it to cool, and top off the expansion tank.
- Start the engine and check if the cooling fans cycle on and off at the appropriate temperature.
- Have protective gloves, clothing, face/eye protection, and absorbent towels on hand when doing this.
- Be careful when working around a running engine.
- Never open the bleed screw or expansion tank cap on a hot engine.
- Ensure your towel is not too large that it can get caught up in the water pump belt, etc.
- Coolant isn't great on your timing belt or paint. Take precautions to keep it off. The manufacturer recommends rinsing the belt off with water if that happens.