Wednesday, July 31, 2024
1981 Alfa GTV6 Dealer Press Release Intro
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.
Thursday, January 12, 2023
Alfa GTV6 US and Euro Ride Height Specs
When the Alfa Romeo GTV6 hit American shores in 1981, the car we received was modified to meet DOT and EPA standards. Luckily, there weren't drastic differences between European and North American spec cars. .
Some of the main differences between a North American and Euro-spec GTV6:
- Impact absorbing bumpers
- Standard Leather interior (1981-84) and air conditioning
- US-approved sealed beam headlights and side markers
- 85 mph speedometer (used on cars through 1983)
- Catalytic converter with Lambda control and specific engine calibrations
- Catalytic converter overheat and oxygen sensor replacement warning light
- New ignition distributor with a different advance curve and added vacuum retard mechanism
- Slightly less power: 154 hp @5500rpm vs. Euro's 158 hp @5600rpm / 151.9 lbs.Ft @3200 rpm vs. Euro's 156 lb.Ft @4000 rpm
- Raised ride height to meet DOT headlight height standards
A common modification to US GTV6 models is lowering the front end height to European specifications or even lower. This can be "easily" done by adjusting the front torsion bars. I use quotations around "easily" because 40 years later, the torsion bars may be rusted or frozen in place and a bear to unseat.* Dealing with that is a story for another day.
How To Check Your GTV6's Ride Height
Below are the GTV6 ride height specifications if you want to check yours. These checks are done with stock tire sizes, pressures, and a specified weight of 210kg / 462 lbs added to your car in specific locations. This weight corresponds to three people that weigh 154 lbs each. I feel sorry for the person sitting in the back seat on the center storage tray!
US GTV6 models have a center tray between the rear seats. European cars that I have seen do not. If you have a European car that has the tray, feel free to let us know in the comments!The manual tells you to disconnect the sway bar and shock absorbers front and rear to remove any of their influence on ride height. They also want you to loosen the Watts linkage bolts to the body. It is hard to say how many people do that, but it makes sense. Owning an older Italian car was never going to be easy.
Once you have the weight loaded into your car, you measure the differences between the two locations. Location "A" is at the bottom of the ball joint stud. Location "B" is the bottom of the lower control arm mounting bracket. Below are the specs:
1981 European Alfa GTV6 Front Ride Height**
- B-A=44MM +/-5
- B-A=50MM +/-5mm
US Spec 1982 Alfa GTV6 Front Ride Height
- B-A= 60MM +/-5
** Original 1981-82 European Inspection Specification Manual (publication date 1/81) states 44 mm ride height. The late manual for model years up to 1983 model year ( publication date 3/84) uses 50MM spec and states this manual replaces and supersedes all older manuals on the subject. Which measurement do you use? Taken at face value, the later manual is supposed to be the revised measurement. If you are new to older Alfas, get used to discrepancies and ambiguities like this.
Note: Left and Right side differences should not exceed 5mm.
For the rear, the measurement when loaded is the same for the US and European markets. The "C" measurement should be 34 mm +/- 5 mm. It can be adjusted by inserting a shim in the upper spring seat. At one time, shims sized 7,14 and 21 mm were available through your dealer. Now, you'll have to make them. An Alfa Romeo technical bulletin cautions to not use a shim larger than 21mm as coil binding may occur.
Okay, but I don't have three friends weighing 154 lbs each, and I've got other things to do. So how's this info going to help?
You can use the above information to plan your lowering target.
As you can see, the difference in height between a US and Euro car at the specified weight is nominally 10mm, but taking tolerances into account, it may be as much as 26mm. Interestingly, the original European 4-cylinder Alfetta models from the early 70s use the 39 to 44 mm spec.
Keep in mind if you want to lower your car, there are some negatives. Be warned that the GTV6 is already prone to grounding on speed bumps, driveways, etc. If you run headers and lower your car, you will likely dent them. Also, the engine's beautifully finned oil sump becomes even more vulnerable.
Lowering a GTV6 too much can result in excessive negative camber, necessitating modifying the lower control arm mounts to bring the car back to specs. In addition, the suspension geometry can be affected, diminishing the handling. Also, the car will be prone to constantly bottoming out on the bump stops, ruining the ride. And, of course, a wheel alignment should be done after any suspension work.
Tuesday, December 6, 2022
Certificate of Origin Alfa Romeo GTV6
Alfa Romeo offers a service where they can send you a Certificate of Origin for your car. The Alfa Romeo Certificate of Origin documents when your vehicle was made and other information. Some may consider it a neat novelty to have, but there is also a practical side where it can help during a restoration and may even add value when selling your car.
Alfa Romeo offers this service for all their vehicles. However, the information varies depending on the model, year of manufacture, and sales market. For my 1982 GTV6, production date, interior, and exterior colors. An engine number confirmation was available if you provided them with the number stamped on your block. Some cars may have more or less information.
The Alfa Romeo GTV6 Chassis Number or Body Number location is shown in the image below. The Vehicle Identification Number (VIN) is the plate seen through the windshield.
Once you have the Chassis Number, contact Alfa Romeo, they will reply with what information is available and give you the cost of the service. At the moment, Alfa Romeo charges 120€ for the service. The breakdown is below (note the tax. Ouch!).
- Certificato di Origine ALFA ROMEO - 98.36€
- Tax - 21.64 €
Go to the Alfa Romeo Museum's Certificate of Origin's link:
Alfa Romeo Certificate of Origin Form
Here's their direct email address.
centrodocumentazione@museoalfaromeo.com
The Certificate of Origin is printed on fancy, high-quality paper, and is sent only in the Italian language. A preview will be emailed in English.
Below is the email I was sent:
Dear Mr Vitale,
Please find attached the preview with the information related to the chassis number you have requested.
Kindly note that we will send the document, printed on high-quality paper, to the address provided with the confirmation of the quote.
Thank you and kind regard
From the production registers held in the Centro Documentazione Alfa Romeo, the chassis number
ZAR 11669000002475
originally corresponds to:
- Alfa Romeo GTV 6 2.5 USA
- Production date: 1981, November 18th
- Exterior color: Nero metallizzato
- Interior: Pelle color blu
- Note: Engine number AR A50820 corresponds to the engine first mounted in the vehicle.
Saturday, November 5, 2022
GTV6 Green Distributor Primary Wire
Thursday, October 27, 2022
Alfa GTV6 Coolant Fan Switch
The Alfa Romeo GTV6 uses a coolant fan switch in the radiator to turn the fans on and off. This 2-prong switch is located on the driver's side of the radiator, just above the lower radiator hose. When the temperature of the coolant leaving the radiator reaches a set point, the contacts close in the switch and fans turn on.
The thermostat on an Alfa GTV6 begins to open up at 176°F (80° C). The coolant fan switch in the radiator turns the fans on at 183.2° - 190.4 ° F (84-88° C). A coolant temperature sensor in the thermostat housing controls the temperature gauge in the car and turns on the overheat warning light at 221°F (105°C).
My Alfa GTV6's radiator coolant fan switch is marked to turn on at 187° F (86° C) and turn off at 169°F (76°C). When you install this switch, use a new 22MM aluminum sealing washer. By the way, this is the same size as the GTV6's oil drain plug washer, so you may have one. The wrench size is 1 1/8 inch or 29mm. Alfa Romeo also recommends using anti-seize on the threads to help sealing.
Alfa Romeo GTV6 Radiator Cooling Fan Switch Specs
- Temperature: 183.2 - 190.4 ° F (84-88° C)
- Tightening Torque: 14.5 - 18.1 ft.lb (20 - 25 Nm)
- Wrench Size: 29mm or 1 1/8 inch
- Thread Size: 22x1.5mm Thread size
- Sealing Washer Size: 22MM Aluminum
- Sealant: Anti-seize
- Alfa Romeo Part Number: 60506988
The good news is this 2-prong switch is a common design and used by other car companies like Fiat, VW and Audi, so it is readily available. Note, you may have to modify your connector to use a non-original one. Also, be careful to match the temperature specifications.
Tuesday, October 25, 2022
Alfa GTV6 Timing Marks
The Alfa Romeo GTV6 is not an ordinary car, and some of its mechanical components have a bit of an enigma surrounding them. One of these features is the mysterious markings on the crankshaft pulley used for ignition and valve timing. It is essential to have a perfect understanding of these marks, or you can get into trouble, so stick around.
While most cars use numbers or hashmark either on the crankshaft pulley or timing cover to verify engine timing, the Alfa GTV6 uses a confusing bunch of letters. On top of that, depending on if you have a US or Euro-spec car, only some of these letters coincide. So if you don't realize you are using a Euro-car repair manual or a North American manual, you can get screwed up. Fear not; we'll help decipher these letters like a pro.
Looking at the crank pulley on a North American GTV6, you will see R, F, P, and M etched into the crank pulley. This differs from Euro-spec cars that just have P, F, and M.
The letters correspond to the following Italian words:
- R - Ritardato or Retarded
- F - Fisso or Fixed
- P - Punto or Point/Dot
- M -Massimo or Maximum
Above the crank pulley, there will be a pointer on the front engine flange that you line up to these letters.
Early Alfa GTV6 Timing Mark
On a 1981 -mid-1983 North American GTV6, the marks correspond to:
- R- 5° +/- 1° ATDC (After Top Dead Center)
- F and P - TDC (Top Dead Center)
- M - 26-29° BTDC (Before Top Dead Center)
Base ignition timing at the 800 -1000 rpm idle with the distributor vacuum line connected should be at the R mark (or 5° +/- 1° ATDC). Note, with the vacuum hose disconnected, timing will advance to the P (TDC) mark.
Timing at 5,000 with the distributor vacuum line disconnected should be at the M mark ( 26-29° BTDC).
Late Alfa GTV6 Timing Marks
On some late-1983* and newer North American GTV6, the marks correspond to:
- P - TDC (Top Dead Center)
- F- 2° BTDC (Before Top Dead Center)
Cars from about late-83* and up use the Bosch EZ-L digital electronic ignition system where you just set initial advance. The distributor's internal centrifugal advance mechanism is eliminated and combined within the electronic control unit. In addition, a vacuum advance capsule boosts part-throttle performance and fuel economy during part throttle operation.
Initial ignition timing at the 950 +/- 50 rpm idle speed with vacuum hose disconnected is 2° BTDC.
European Alfa GTV6 Timing
- P - TDC (Top Dead Center)
- F- 7° - 10° BTDC (Before Top Dead Center)
- M - 28-31 ° BTDC (Before Top Dead Center)
The European GTV6 ignition system is similar to the early North American car's setup. Different initial timing, advance curve, and the elimination of vacuum retard are the main differences.
Timing at 5,000 rpm with the distributor vacuum line disconnected should be at the M mark ( 28-31 ° BTDC).
Alfa GTV6 Top Dead Center Mark
P - TDC (Top Dead Center)
The P mark on the crank pulley corresponds to TDC on all GTV6 models.
Timing Mark Degreeing the GTV6 Crank Pulley
If you own an Alfa Romeo, you likely enjoy modifying and trying to improve its performance. If you are doing an engine mod, accurately knowing the crankshaft degrees during an event like ignition, valve opening/closing, etc., is vital. With the marks you have on the crank pulley, you can figure out the distance of each degree and mark them off. For example, on my North American 1982 GTV6, every degree is approximately .040" or 1.016mm apart.
I have a European distributor installed in my car and want to time my engine at 10° BTDC. I simply measured the distance between P and R (equals 5°) on my crank pulley and came up with approximately 5mm. So, I placed 2 marks 5mm apart BTDC, corresponding to 5° and 10°. Simple. You could do that all around the crank if you desire.
* Documentation shows 1983 50 State (California) emission compliant GTV6 models came with the late ignition systems.