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Q1.1. What's a 911?

Q1.2. What are the differences between the various 911s?

Q1.3. Okay, so how do I tell the difference between them?

Q1.4. But, Porsches are known for performance; how do the models differ?

Q1.5. What should the VIN or engine number look like for my car?

Q1.6. Why did the early 911s have two batteries?




Q1.1. What's a 911?

Yikes. Okay, in 1963 Porsche announced the 901, a car based on the venerable 356 model. The car was renamed 911 because Peugeot had a copyright on all 3-digit car model numbers with a zero in the middle. The 911 has gone on to become, arguably, the most popular car ever produced by Porsche. The 911 engine is an air cooled (or oil cooled) six cylinder opposed design (%). The cylinders bolt onto the crankcase such that displacement increases are often achieved by replacing the pistons and cylinders. The body of the car was designed by Ferdinand "Butzi" Porsche (Ferry's son) while the engine was designed by Ferdinand Piech (Dr. Porsche's nephew). It is not a boxer design. A boxer engine has not only a 180 degree layout, but has a flat crankshaft arranged so that the matching pistons are at top-dead-center at the same time (so that the pistons move, alternately, toward or away from each other).

Q1.2. What are the differences between the various 911s?

There's *lots* of differences:

Numerous of body styles Coupe. 4 seats (well, 2 and a couple postage stamps) and a hard roof. You know. . .a COUPE Targa. Like a coupe, but with a roll bar and a removable top. The earlier targas had soft rear windows, but the later ones had glass. Cabriolet. A full-on convertible. Speedster. A version of convertible, but with a short windshield and a fiberglass tonneau (the 356 speedster was different, but we're talking about 911s here). Several trim and tune options. T, E, S. The early years (the latest any of these were produced was 1977) cars in touring, injected and super (also fuel injected) states of tune. Carrera. For the earlier cars, this was the quickest standard customer car. After 1983, the Carrera was the standard customer car. SC. This was the standard car (there was also the turbo for some of theses years) between 1978 and 1983. H, N. Rare models: 911RS Homologation (20 made in 1973) and a Euro model in 1976. L. The one-year replacement for the 911S in the US. R, RS, RSR. 911 in race trim. These cars are always rare and expensive. Turbo. This one is, well, turbo charged. Model Year Differences. And, finally, there are the various changes over the different model years. Major Eras Include (the names are, partly, my own):

1964-1968 short wheel base (SWB, 2211 mm to be exact). In contrast, the long wheel base (LWB) is 2268 mm long.

1968-1973 early power. These 2.0, 2.2, and 2.4 liter 911s (my personal favorites) saw either mechanical fuel injection or carburetors (actually, in 73.5, the 911 T was electronically fuel injected).

1974-1977 middle-year 911s. These cars had the 2.7 liter engines that had a notoriously short life span. This is the beginning of the crash bumpers (with the accordion sections at the edges) and K-Jetronic fuel injection.

1978-1983 911SC. These 3.0 liter SCs are powerful, luxurious, and nearly bullet-proof.

1984-1989 Motronic Carreras. Like the 911SC, but with a 3.2 liter engine and Motronic fuel injection.

1989-1994 964 (original 911 Carrera 2/4). These cars have the one-piece, all body color bumpers and the engine cover that raises at 50 MPH to form a wing.

1994-today 993 (today's 911)

Note: Years given are model year. The model years start in August or September of the previous year (example 1972 model year starts in September of 1971). Much of the research for this document has been clouded by research materials not specifying whether they discussed calendar year or model year. More specific differences are given in table 1, below.


Q1.3. Okay, so how do I tell the difference between them?
Well, you asked for it. . .


Short Wheel Base 1964-1968

1968 and earlier cars have a shorter wheelbase than the 911s built in 1969 and after (recognition hint: the torsion bar tubes are right next to the SWB cars' rear wheel well -- there's a gap in the LWB cars). Other accoutrements of the SWB cars are: glass lens covered headlights, exterior door handles that opened via an exposed push-button (rather than the flying-buttress protection or trigger of later years), no side marker reflectors, Hella 128 fog lights mounted through the bottom half of the front bumper, a vertical structural strip running under the rear engine grille, sunroof models during these years had a drain slot above the rain gutter above the back side windows, And, in the interior: chrome instrument bezels with green lettering, ceiling-mounted rear-view mirror (1968 was as well, but it was break-away type) a one piece under-dash knee guard,pleated door pockets, and push-buttons to open the doors from the inside. Until 1971, non-S models had silver painted slotted steel wheels; S models had Fuchs alloy wheels. 911s before the 1967 model year had the '911' designation diagonally across the lower right corner of the engine cover and the PORSCHE script in one piece (well, actually it was two pieces, but it looked like one) on the bottom.

1964 2.0 liter

There were four 901 prototypes produced (serial numbers 13326, 13327, 13328, and 13330). Porsche went on to build 125 first year (1964) 901 cars.

RECOGNITION TIPS:
The 1964 cars have no rocker-panel trim and and no model designation on the engine lid or on the dash. Supporting clues are that 1966 and earlier 911s have wooden dash trim and open A-frame window cranks.

1965 2.0 liter

RECOGNITION TIPS:
These cars look nearly identical to the 1966 cars. The things that separate these cars from the 1966s is in the interior. The 1965 cars have no wrap-around knee guard, aluminum backing on the wood dash trim, or rubber shift boot (I think they were leather). Both years are similar in that they have the rocker panel trim (this is not found on the 1964 cars), wooden dash trim, and open A-frame window cranks.

OPTIONS:

A four speed transmission became standard mid-model year. Sunroof, tinted windshield, enamel porsche crest on wheels, chrome plated steel wheels, gasoline heater (LHD models only), ambient temperature gauge, driver's side vanity mirror on sun visor, recaro or ferrari seats (actually, both are made by recaro), leather seats headrests

1966 2.0 liter

Weber carbs replace Solex mid-model year. S model introduced mid- model year. Fuchs wheels introduced. Targa (with soft rear window) introduced. 911 introduced in US.

RECOGNITION TIPS:
These cars look nearly identical to the 1965 cars. The things that separate these cars from the 1966s is in the interior (see the 1965 description). Of course, if the car is an 'S' model, it has to be a 1966 or later. US models have all chrome vertical bumper guards (standard equipment) -- 911S bumper guards are all rubber.

OPTIONS:

sunroof, tinted windshield, enamel porsche crest on wheels, chrome plated steel wheels, gasoline heater (standard on S-models) (LHD models only), ambient temperature gauge, driver's side vanity mirror on sun visor, recaro or ferrari seats (actually, both are made by recaro) leather seats, headrests

1967 2.0 liter

Only 4 prototypes and 19 'production' 911Rs were made.

RECOGNITION TIPS:
The window cranks on 1967 cars are of the covered A-frame type but had a hard plastic knob. US Models have chrome vertical bumper guards with a rubber strip (standard) -- 911S bumper guards are all rubber. The bases for the switches on the dash go from black to chrome and the dash is matte black (S model had basket weave vinyl).

OPTIONS:

Rear window wiper optional from this model year on (on Targas, too?), tinted windshield, rear-window defroster (vertical wires), sunroof, sportomatic (introduced in 1967), enamel porsche crest on steel wheels, chrome plated steel wheels, Fuchs alloys on non-S models, 100 liter fuel tank, gasoline heater (standard on S-models) (LHD models only), ambient temperature gauge, leather covered steering wheel (standard on S-models), driver's side vanity mirror on sun visor, leather seats, headrests, recaro sport seats (available in leather, vinyl, vinyl with with corduroy, or vinyl with hound's tooth inserts).

Early Power 1968-1973

Side marker reflectors appear in 1968 (tacked-on side reflector) -- in 1969 and later, the reflectors are incorporated into the turn indicators. 1968 and later 911s have the model designation mounted horizontally centered on the engine cover (the hood?). The covered headlight is replaced with a rim bezel over a sealed beam headlight (US) or a lens covering bulbs (non-US). Inside, the window cranks are one-piece with a soft vinyl knob. The door pockets under the arm rests are vinyl-covered hard cardboard. 1969 is the first year of long wheelbase 911s; these came with flared fender arches; also, the targas come with glass rear windows. The 911s between 1969 and 1973 used a 2 battery system. From 1970 on, the doors opened via trigger-type door handles. The under-dash knee guard is a two-piece (with room for the ash tray in between) unit during this time period. 1969 and later, the rear-view mirror is mounted to the windshield.

1968 (A Model) 2.0 Liter

A very few targas had glass rear windows at the end of the model year.

RECOGNITION TIPS:
Matte black wiper arms. US Models have chrome vertical bumper guards with a rubber strip (standard) -- 911S bumper guards are all rubber. S Models have chrome vertical bumper guards with a rubber strip. Knobs on the dash are now rubber covered. 1968 US models only, 911s had tacked-on rectangular side reflectors in front and back. Two-piece dash pad (1968 only). Matte black dash (S and L models had basket weave or elephant hide vinyl). Rear-view mirror is break-away and ceiling-mounted.

OPTIONS:

sunroof, Sportomatic transmission (1968-1971), tinted windshield, rear- window defroster (vertical wires), a chrome bar (optionally with leather rubber covering), connecting the top of the rear vertical bumper guards (where bumper guards exist), a 3-piece stainless steel muffler skirt (hanging below the rear of the car), enamel porsche crest on steel wheels, chrome plated steel wheels, Fuchs alloys on non-S models, 100 liter fuel tank, gasoline heater (LHD models only), ambient temperature gauge, leather covered steering wheel (standard on S-models), leather seats, headrests, recaro sport seats (available in leather, vinyl, vinyl with corduroy, or vinyl with hound's tooth inserts) are available on non-US cars.

1969 (B Model) 2.0 Liter

All new forced air ventillation system. Heated rear window standard. Targa had glass rear window. 911T came in an normal and 'Lux' configurations. 911T has all chrome bumper guards (rubber strip is an option); 911E and S have all rubber bumper guards. After 1968, side marker reflectors were incorporated into the turn-signal indicator.

RECOGNITION TIPS:
First year of long wheelbase 911s; these came with flared fender arches. Dash was basket weave vinyl (1969-1971). If it's a LWB car with push- button outside door handles, it's a 1969.

OPTIONS:

Hydropneumatic struts on S model, Hella 169 fog lights (not available in US), sunroof, tinted windshield, Sportomatic transmission (1968-1971), aluminum wheel arch mouldings (E and S models), sportomatic, 5 speed (T and E models), rear-window defroster (horizontal wires), a chrome bar (optionally with leather rubber covering), connecting the top of the rear vertical bumper guards (where bumper guards exist), a 3-piece stainless steel muffler skirt (hanging below the rear of the car), 10-spoke cast magnesium wheel (on T model only), chrome plated steel wheels, 100 liter gas tank (non-US models only), gasoline heater (LHD models only), electric antenna, leather seats, headrests, vinyl and leather door coverings, vinyl or leather (or cloth?) sport seats, electric windows

1970 (C Model) 2.2 Liter

Underfloor areas galvanized with PVC undercoat. 911T has all chrome bumper guards (rubber strip is an option); 911E and S have all rubber bumper guards.

RECOGNITION TIPS:
First year of trigger-type door handles. '2.2' sticker in the back window. Dash was basket weave vinyl (1969-1971). 1967-1970 glove boxes used a key lock which was mounted over the glove
box, but offset toward the center of the car.

OPTIONS:

Hella 169 fog lights (not available in US), Limited slip differential optional, sunroof, Sportomatic transmission (1968-1971), tinted windshield, aluminum wheel arch mouldings (E and S models), rear-window defroster (horizontal wires), a chrome bar (optionally with leather rubber covering) connecting the top of the rear vertical bumper guards (where bumper guards exist), a 3-piece stainless steel muffler skirt (hanging below the rear of the car), 10-spoke cast magnesium wheel (on T model only), chrome plated steel wheels, 100 liter gas tank (non-US models only), gasoline heater (LHD models only), Bosch hydro-dynamic struts (on T and S models only), electric antenna, leather seats, headrests, vinyl and leather door coverings, vinyl or leather (or cloth?) sport seats, electric windows

1971 2.2 liter

911T has all chrome bumper guards (rubber strip is an option); 911E and S have all rubber bumper guards.

RECOGNITION TIPS:
Dash was basket weave vinyl (1969-1971). In 1971, the glove box lock was mounted in a twist knob that appeared centered over the glove box.

OPTIONS:

Hella 169 fog lights (not available in US), tinted windshield, Sportomatic transmission (1968-1971), heated windshield (this year only), sunroof, aluminum wheel arch mouldings (E and S models), rear-window defroster (horizontal wires), a 3-piece stainless steel muffler skirt (hanging below the rear of the car), 10-spoke cast magnesium wheel (on T model only), chrome plated steel wheels, gasoline heater (LHD models only), electric antenna, leather seats, headrests, vinyl and leather door coverings, vinyl or leather (or cloth?) sport seats (standard on S model), electric windows.

1972 2.4 liter

Stroked to get 2.4 liters; compression lowered to run on regular gas. Dry oil sump made of stainless steel. The 901 transmission was replaced, starting in 1972, with the stronger 915 transmission. One result of this is that these cars now use the conventional H shift pattern (drat!). Silver painted slotted steel wheels standard on T model. Seat belts retract in US.

RECOGNITION TIPS:
Matte black engine grille, PORSCHE letters, seat recliner bars, and (on targa models) targa script. 1972-only had oil filler flap below right-side C-pillar. '2.4' badge on engine grille. Rectangular side Mirrors. Dash was leather grain vinyl (1972-1973) with no model designation.

OPTIONS:

Front spoiler optional, Sportomatic on E and T models, 5 speed on all cars in US and on T models in UK, Larger fuel tank (with space saver spare), 6Jx15 alloys, Hella 169 fog lights (not available in US or on E or S), tinted windshield, aluminum wheel arch mouldings (all models), rear-window defroster (horizontal wires), sunroof, a 3-piece stainless steel muffler skirt (hanging below the rear of the car), 10-spoke cast magnesium wheel (on T model only), gasoline heater (LHD models only), electric antenna, leather seats, headrests, vinyl or leather door coverings, vinyl or leather (or cloth?) sport seats, electric windows

1973

Better oil cooler, stronger main bearings. Large fuel tank standard (electric compressor provided for the little-bitty tire that fits around the fuel tank). Front air dam standard on all models. 911 T and E available in standard and Lux versions. Targa available mid-year in UK. Silver painted slotted steel wheels standard on T model. E model used cookie-cutter wheels as standard. Seat belts retract in US. This year only, Porsche produced the 2.7 liter Carrera RennSport or Carrera RS -- this was available in four versions. The RS Sport and the RS Touring (RST) were the main customer Carreras. Moreover, the many of the early RSs were made in lightweight form making them extra fast (and extremely valuable). More esoteric RSs were the twenty RSH, or Homologation, models and the 2.8 liter RS Racer (RSR).

RECOGNITION TIPS:
Matte black engine and horn grille, PORSCHE letters, and (on targa models) targa script. Bumper guards on US models are made entirely of rubber. Rectangular side mirrors. Carrera had 'ducktail' rear wing. Dash was leather grain vinyl (1972-1973) with no model designation.

OPTIONS:
Fuchs alloys on T model, Hella 169 fog lights (not available in US or on E or S), sunroof, tinted windshield, aluminum wheel arch mouldings (all models except Carrera), rear-window defroster (horizontal wires), a 3-piece stainless steel muffler skirt (hanging below the rear of the car), gasoline heater (LHD models only), leather seats, headrests

Middle Years 1974-1977

Shock absorber bumpers, seats have fixed headrest. Along with the fat bumpers, the trunk (front of the car) goes from curved-over to flat where it hits the bumper. The main-line cars all have 2.7 liter displacements with CIS fuel injection.
1974 (G Model) 2.7 liter Carrera available only in Coupe and Targa versions (no Sport, Touring, or Racing versions).

RECOGNITION TIPS:
Carrera 2.7 had 'ducktail' rear spoiler (but shock absorber bumpers). The bumper guards on US-model 1974 cars were only about 3.5 inches wide. Newer cars have 7 inch wide bumper guards. Note that the 1974 cars do *NOT* have thermal reactors (non-US cars never had them); these things generate a lot of heat and, therefore, heat-related problems.

OPTIONS:
5-speed transmission (US -- this was standard in UK) or 4-speed Sportomatic

1975 2.7 liter

There was a silver anniversary edition of the 911 with silver cloth in seats and doors and black leather trim.

RECOGNITION TIPS:
Black targa roll bar.

1976 2.7 liter

Carrera comes in regular and sport trim. Entire body covered in zinc for rust protection. 5-bladed engine fan (rather than 11). Five speed transmission standard in US and UK.

RECOGNITION TIPS:
External mirror painted body color. Headlight washer is of the stick-up variety between 1976 and 1979.

OPTIONS:
sportomatic transmission, Koni adjustable or Bilstein gas/oil shocks (S Model), external oil cooler, forged alloy wheels, sport seats, electric sunroof, electric windows, air conditioning

1977

Cars fitted with extra air pump, twin thermal reactors and exhaust recirculation. Improved gear box.

RECOGNITION TIPS:
Headlight washer is of the stick-up variety between 1976 and 1979.

OPTIONS:
sportomatic transmission, 5-speed transmission, center console 911SC and Later 1978 on The fenders were flaired more dramatically from 1978-on. The rear badge of the 1978-1983 cars had, of course, the '911SC' designation. Between 1984 and 1988, the badge on the engine lid indicated the then-current model name, "Carrera". From 1980-on, the headlight washers were mounted flush with the front bumper. The cabriolet body type was offered for the first time in 1983.

1978

5-speed standard. SC comes in standard and sport configurations.

RECOGNITION TIPS:
Headlight washer is of the stick-up variety between 1976 and 1979.

OPTIONS:
air conditioning, power windows, last year of the Sportomatic transmission

1979

SC horsepower increased mid-model year to 188.

RECOGNITION TIPS:
SC now has black window frames, electric windows. Headlight washer is of the stick-up variety between 1976 and 1979.

OPTIONS: air conditioning

1980

SC now has air conditioning and electric windows standard. The 911SC Weissach edition was available in 1980. Flush-mount headlight washers start in 1980.

1981

SC was given a higher compression ratio for 1981. The SC still comes in standard and sports configurations.

RECOGNITION TIPS:
Indicator side marking lights.

OPTIONS:
sports seats, berber cloth upholstery, leather upholstery

1983

The Cabriolet was offered for the first time in 1983. This is the last year of the 911SC.

1984

RECOGNITION TIPS:
The easiest key is that the post 1983 cars had the name 'Carrera' on the engine lid rather than '911 SC'. These cars used the 'old' non-electric seats. Fog lamps in front spoiler.

OPTIONS: air conditioning

1985

RECOGNITION TIPS:
First year of the electric driver-side seat.

OPTIONS: Electric passenger-side seat.

1986

More effective air flow due to redesign of the ventilation system.

1987

New transmission with a hydraulic clutch is standard.

RECOGNITION TIPS:
The black "PORSCHE" script on the rear reflector is dropped this year in favor of clear script. Halogen headlights (rather than sealed beam) are now fitted on US cars.

1988

959 available in sport and comfort trim. 911 Speedster . . 217n 195n . .

OPTIONS:
limited-slip differential (possibly turbo only), 16 inch wheels (possibly carrera only), alarm system (possibly carrera only), 7" wide front tires (carrera only), 8" wide rear tires (carrera only)

1989

RECOGNITION TIPS:
Aside from the "Carrera 4" script on the back of the engine lid (the Carrera 2 came by in 1990), this is the first year of the new smooth, body- colored bumpers. This is also the first year for standard dual airbags and ABS.

1990

OPTIONS: electrically adjustable seats

1991-1993 1994 1993 (first year for ROW)

RECOGNITION TIPS:
This is the first year of the 993. This car stands-out with sloped headlights, a larger engine cover/movable rear wing, and a handle- like fixed wing (with integrated third brake light) over the back engine cover.

OPTIONS: Available in Speedster configuration.

1995 993 (first year USA)

OPTIONS: Tiptronic


Q1.5. What should the VIN or engine number look like for my car?

Well, I'm not going to go into that here 'cause it's long and there are so many other books that do it completely. For VINs, check out Bruce Anderson's "Porsche 911 Performance Handbook" or "Guide to Purchase & DIY Restoration of the Porsche 911". For both VINs and engine numbers, consult Brett Johnson's Restorer's guides or "The Used 911 Story" (for US cars only).


Q1.6. Why did the early 911s have two batteries?


As per Pete Albrecht:

Very early cars also had cast iron (NOT LEAD!) weights in the outer corners of the front bumpers for the same reason.
[Tobias] Aichele's book, ["Porsche 911: Forever Young", Beeman Jorgensen, 1995] recounts the tests run with various configurations (originally lead weights for testing only). In tests supervised by Helmuth Bott, with the weights in the outer corners of the bumpers, the steering had an appreciably higher self-centering moment. Moving the weights to the center of the bumpers worsened the handling characteristics again. "The inescapable conclusion was that the handling problem was not only caused by the weight distribution, but was also sensitive to the car's polar moment of inertia. Helmuth Bott draws an analogy: 'These laws of physics are even used by ice skaters, when they spread their arms to slow their rotation or pull them in to turn faster.'"...

"Bott took a front bumper to the Bodenmueller foundry, located across the street from Porsche, and had sand molds of the bumper tips made. These molds provided iron castings weighing 24 lbs which were cemented into the bumpers with a particularly tough adhesive and also clamped by the bumper's mounts." ..."Helmuth Bott recalls that "We didn't want to publicize this solution with its reinforced bumpers, but we were happy to have found a bolt-on remedy."

The bumper weight idea is an extension of the idea of mounting the batteries as far toward the corners of the car as possible. Peter Albrecht, PLAlbrecht@aol.com, "Why twin batteries",

951019125859_48727898@mail06.mail.aol.com

On the other hand, Derek Cahill suggests:
[...] There is a LARGE amount of oil in a 911 engine, and in order to get it moving on a cold morning, using the best technology of 1967, two batteries were needed (there was no such thing as a battery with 800 CCA's readily available back then, so two 400-450's did the same job) to provide the necessary power to start the car. Derek Cahill,"Re: Twin Batteries why",

Pine.3.89.9510192013.A27106-0100000@freenet3.scri.fsu.edu

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