1971 Buick (Riviera) facts and info I've collected


Riviera General data
Model 49487-Two-Door Coupe 1971 production Incl GS....33,810
Standard engine : 455-4 V8
Compression Ratio: 8,5 : 1
DisplacementL 455 C.I.D.
Carburation: 4-barrel quadrajet.
Transmission: Riviera: 3-speed Turbo Hydra-matic 400 automatic transmission. Riviera GS: specially calibrated 3-speed Turbo Hydramatic 400 Automatic Transmission Early 1971 model year cars will likely have an OW transmission, while later model year cars will likely have a BB transmission..
Rear Axle Ratio: Riviera: 2.93 Riviera GS: 3.42 with postive traction.

1971 Buick Exterior Colour chart

The 330 horsepower, 455-cubic-inch Riviera GS engine is essentially a carryover from the 1970 Riviera except for a 40-horsepower detuning for operation on 91-octane gasoline. This optional GS engine produces this 330 hp and 455 foot-pounds of torque, thanks to a slightly hotter cam that peaks the horsepower at 4.600 rpm.

Dimensions.
Overall lenght (inches) 217.4
Width 79.9
Height 54.0

Weight (los) 4437

Suspension.
Front Stamped A-frame upper
and lower control arms,
coil springs and ball
joints, link stabilizer.
Rear 4-link, coil springs

Performance.
Standing quarter mile 15.9 sec
Speed at end of 1/4 mile 88 mph
0-60 mph 8.4 sec

The Question I get asked after what is it? - what year is it? how big is the engine? - how fast does it go? - did come with all that stuff? is do those louvers on the trunk do anything?
yes they do here is the expalnation from the owners manual

The big boattails have an amazing performance. Several road tests where surpised to see this heavy coupe accellerate from 0-60 mph. in just 8.4 seconds.
Most standing quarter miles came in around 15.9 seconds at 88 miles per hour; not bad at all for a car with air-conditioning and every other accessory they could imagine in 1971.
On cars equipped with the max-trac device accellerationtakes place without any wheel spin, nice, but it won't give the kick of an accelleration with a lot of noise and smoke.12 bolt limited slip rear diffs keep things nice and straight but is no where as neat as both back wheels smoking.
The performance of the 72 and 73 model dropped dramaticaly because of emissions additions. The 455 was choked to just 225 hp (standard) and 260 hp (GS) instead of 315 hp (330 hp for the GS) in 1971.
For the looks and great performance 1971 was definatley th� year, especially the 1971 Riviera GS and Stage 1 .
Bumper regs i think ruined the Riv in 73 curb weight was up to 4500 pounds. This power to weight handicap conspired with the radical looks and slashed sales, the 74 and 75 got a bit better.
The 1972 model still had the looks but performance was not that of 1971. For 1973 the Riviera had just the roof line and window section left.

Stage 1 numbers
All Stage 1 455 cars used a different carb and distributor than its standard counterpart. The numbers are as follows:
Year Carb # Distributor #
1969 7029246 1111962
1970 7040246 1112016
1971 7041241 1112016
1972 7042242 1112016

The real nitty gritty of engine i.d. is the engine code. It is stamped on the block deck between number 5 and 7 spark plugs.
For GS stage 1 optioned cars the key letter here is "S" The second letter of the code MUST be an "S" A 1969 would be RS, 1970 is SS, 1971 is TS and 1972 is WS.
Non Gs Stage 1's Optional engine (not stated as stage 1 in GM specs book) 345 hp included with Stage 1 option - no markings no special carb distrib or posi - engine code is BG trans code BC

The last three digits are the production code for the build date and is not used for Stage 1 idenitification.
The VIN is stamped on the block between number 1 and 3 spark plugs on 1969 and 1970 models. It is on the face of the driver's side of the block beneath the power steering pump on 1971-2 models.
If the last six digits of this number match the last six of the VIN then this engine originally came in the car. If not, the engine has been changed.
The trans also has a VIN stamped onto the case. Again if the last six digits match the dash VIN tag the trans is the original.
1970 455 GS BA
455 GS Stage 1 BB
455 Riviera BT
455 all others BC
1971 455 GS BS
455 GS Stage 1 BB, OW
455 Riviera BT
455 all others BC
1972 455 GS BS
455 GS Stage 1 BB
455 Centurion high performance BU
455 Riviera GS other models with performance rears BT
455 all others BK,BC

The driver's side axle tube has two letter code stamped on it. The 3.42 used code OO with 3.64 getting ON. These codes also designate posi. Some axle tubes may not have any stampings.
Beginning in 1971, the rear axle was increased to 8.5" ring gear. It visually became different from 1969 to 1970 design and carried different letter codes. The code for 3.42 was LWB or LW.
Just for the record, 12 bolt rears were not available in any GS only 10 bolt posi. The Canadian built 12-bolt rears are limited slip not posi.

400, 430, 455 inch, all have the actual cubic inch that the block was cast for in the transmission mount saddle above the casting number.
GS and Stage 1 engines were seperate packages with the GS being part of the overal sport apperance package and Stage 1 being an Engine performance(mainly heads)upgrade.
1971
V-8 455 4bbl TR,BH
V-8 455 4bbl GS TA
V-8 455 4bbl GS Stage 1 TS
V-8 455 4bbl Stage 1 BG

On models from 1972 through 80, the fifth character of the VIN provides engine identification. This character appears on the dash VIN plate, but not on the engine itself.

YEAR ENGINE TYPE CODE VIN
1972

V-8 455 4bbl single exhaust WF T
V-8 455 4bbl dual exhaust WF U
V-8 455 4bbl, Stage I WS V
V-8 455 4bbl WA W Riv GS
. 400, 430, 455 inch, 1968 on
The engine serial number is between the two front spark plugs and the left exhaust manifold, and the production code number is between the two rear plugs and the exhaust manifold, also on the left.

The Gran Sport Option
A GS option was available for the 1971-1973 Riviera.
Cars so equipped had a 330 horsepower (instead of 315 hp) 455 cubic V-8 with chrome air cleaner top linked to a specially calibrated Turbohydramatic 400 transmission (that is for 1971 cause the 1972 GS was down to 260hp due to emission control regulations); F 40 heavy duty suspension and handling package;heavy duty springs and wheels (7 inch) positive traction differential; H78 x 15 Bias Belted whitewall tires and Riviera GS monogram on front fenders. Some people say these options were not just nice but necessairy to keep this monster on the road.
The posi rear is nice indeed when making a burnout, it will get both wheels spinning and gives nice tracks on the road. That is, on dry pavement.
On a rainy day however, the posi rear isn't that nice when accellerating a bit too fast in a curve. It will have the car turn around a 180 degrees if you you're not familiar with this. An experienced driver is needed for these cars.
Is it a real Riviera GS?
Check this:
does the car have the monograms on both fenders? does it have a chrome air cleaner top?
does it have a positive traction rear differential?
If so, it is most likely a Riviera GS but all these items could have been added afterwards. The engine difference is hard to determine, it should be faster and then there is the heavier suspension package too, but if you have no comparison.
Here's a very good way to determine if it is a clone
or not: On a 71 GS you can't tell it from the engine
code and for 72 its in the VIN.
71 GS engines have 'TA' in the code; the VIN shows
only 455-4 not referring to GS or not.
71 Stage 1 have "TS" or "BG" - all headd castings are #1231786
A 72 GS must have a letter 'W' in the VIN.
For 1973 the 'W' in the VIN shows its a stage-1 engine. Sadly for 1973 it is harder to tell a GS apart from a clone because the GS became a 'handling option'. There you need to check the trans etc.

Accudrive
In cornering the Riviera shines compared to other 71 cars. On the test road on GM's vast Milford prouving grounds, there is a particulary nasty reverse camber curve with an even nastier increasing radius that you decend upon 20% grade. The Riviera took this with no lean and very little tire squeal at 70 miles per hour.
Part of the freedom of tire squeal was due to the fact that Riviera tires were one-of-a-kind that were engeneered for the Riviera, that is: in 1971.
However, the level cornering was not the result of special tires but "Accudrive", a name given to a suspension geometry that reacts against centrifugal force. Up to a point, the harder you corner, the harder the suspension on the outside pushes back against the body's tendency to lean.
The Riviera corners with the best of the 1971 cars.

MAX-TRAC was a traction control system that was way ahead of its time. It measured the speed of the left front wheel and compared it with the output on the transmission. If there was a difference, the ignition would short-circuit so the power on the rear wheels went down.
Because the system had lots of maintenance-problems (I'm glad not to have it on mine) and emission-control regulations would not allow to keep the system as unsophisticated as it was, it was dropped at all for 73.

Below are descriptions from the 71 Buick brochure and from a 72 manual.

Other Riviera Options
There were a lot of options available on the Riviera:
-vinyl roof
-sunroof
-side markers/cornering lights (not on the 73)
-turnsignals on the fenders
-various interior options - bench - split bench - buckets seat vinyl or vinyl with cloth inserts (non had leather, even a lot people think the heavy vinyl is leather, it feels and looks like but doesn't smell or split like) - console - custom (full arm rests wood grain) and deluxe (half arm rests no wood grain) trim levels,
-rally wheels (5-spoke chrome wheels) -
AM/FM radio/8-track
-climate control
-right door mirror (hard to find now, I want one)
-etc.etc.etc in fact so much you dont often find two exactly the same it was all about making your personnel luxury car YOUR personnel car

Here's a list and percentages of options sold per year:

Riviera option installation percentages:
Option 71 72 73
AM Radio 30.7% 14.1% 8.3%
AM/FM Radio 16.8% 12.7% 9.0%
Stereo 4 speaker 3.3% 42.3% 41.4%
Stereo Tape 52.1% 27.0% 34.9%
Power Locks 38.4% 42.4% 57.4%
Power Seats 79.1% 85.4% 87.5%
Pwr Windows 94.9% 96.0% 97.2%
Bucket Seats 28.1% 25.7%
Vinyl Roof 75.1% 69.7% 81.1%
Sun Roof 3.5% 3.5%
Radial Tires 36.4%
Tinted
Windshield 2.4% 2.4% 1.9%
Tinted Glass 96.7% 96.7% 97.2%
Auto Temp
Control AC 12.7% 13.2% 17.3%
Limited Slip 18.8% 16.0% 12.3%
Standard
Wheel Covers 36.7% 23.1% 16.8%
Optional
Wheel Covers 7.7% 4.2% 7.4%
Optional Wheels 55.6% 72.7% 75.8%
Cruise Control 33.2% 44.2% 53.8%
Max Trac 5.6% 5.7%
Rear Defogger 36.8%
Stage 1 engine 3.6%

My Riv has some stuff not even mentioned above
They added more options for each year, that's why the list has some blanks.

Lube chart

Rochester Quadrajet Common Problems and Decoding by George Nenadovich
The Rochester carb is the most common carb found in GM cars and trucks from the 1960's to the mid-1980's when they were replaced by fuel injection units. If the carb is maintained properly, it will deliver years of service. There are a few problems with the Rochester carbs as they get older and/or are not maintained.
A common problem is the fuel filter inside the fuel inlet housing becomes plugged with debris from dirty gasoline. This prevents the float bowl from filling quickly and results in poor engine performance. This filter is not an ideal candidate since it is made of paper and can not be seen unless the filter is removed from the housing. The best filter to use is a glass filter connected in-line between the fuel pump and carb. This filter allows you to see if the fuel pump is working as well as if there is any debris in the fuel.
Another problem is the cam that raises the secondary metering rods when the air valves open. This small heart shaped plastic cam is located between the secondary air valves on the air valve shaft. It is common for this part to break preventing proper operation of the secondary air valves leading to a bog.
Another problem associated with the secondary air valves is the vacuum secondary break. This small vacuum break is located on the passenger side of the carb. These small diaphragms rupture after years of exposure to heat and result in the secondary air valves flopping open causing a bog.
A couple of other problems but not common are the carb being bolted to the intake with excessive torque and fuel well plugs leaking. If the carb is overtightened with the four bolts mounting it to the intake the air horn will be bent creating fuel leaks and vacuum leaks. Always change the base gasket when installing a rebuilt carb for it to create an air-tight seal between the carb and intake. The fuel well plugs can leak and the best way to fix them is to use an epoxy to seal both wells. The wells are located under the bottom of the fuel metering rods.
---------------------------------------------------------------
Rochester Quadrajet Number Decoding
All Quadrajet carbs have numbers stamped on them on the driver's side rear secondary. It is visible when the secondary throttle actuator is opened or the carb is held at an angle. These numbers, 7 digits, indicate what engine the carb is from as well as manual or automatic transmissions, California emissions carb.

For example, the carb #7040246, indicates several pieces of information. The fourth digit, 0, indicates the year, 1970. The sixth digit indicates the make which in this case is 4 which is Buick. By checking the chart below, we see the carb is a 1970 Buick 455 Stage 1 carburetor.

The sixth digit can be one of the following depending on make:
0,1,2 Chevrolet, GMC or truck
3 Cadillac
4 Buick
5 Oldsmobile
6 Pontiac
Buick Quadrajet Codes

---------------------------------------------------------------YEAR CARB # ENGINE TRANS
---- ------- ------ -----
1971 7041245 350 M
7041544 350 A
7041243 455 M
7041540 455 A
7041242 455 Stage 1 A or M

1972 7042245 350 M
7042244 350 A
7042243 455 M
7042240 455 A
7042242 455 Stage 1 A or M

Index
page 1 - The dream comes true - Uhaul nightmare
page 2 - The trip home
page 3 - The Red Riv gets home
page 4 - The sound system install - interior cleanup
page 5 - The interior is back together -sounds are in - ready to roll
page 6 - The Red Rivs first car event
page 7 - The Red Riv gets a checkup and window shops for new shoes
page 8 - The Red Rivs run in with the Law
page 10 - 71 Riv Ads, Brochures, Documents, Road Tests, etc
page 11 - Restoration of the Mini Red Riv - 1/18 scale model
page 12 - The Red Rivs First Cruise and Car Show
page 13 - has nothing because Im superstitious
page 14 - The Red Riv gets ready for fresh paint
page - The 455 is all painted and gets started up