1955 Buick Specifications / Specs
Do you know the differences between a 55 Buick Special and a Roadmaster model? Well, its easy to find them – just read these 1955 Buick Specifications! They cover all important specs for all series!
Learn more about engine specs, engine parts type and measurements plus drive units like the rear axle! Get to know what brake material was used back in 1955! With these 1955 Buick Specifications you can tune your restore classic car easily.
| General Information | Special Series | Century Series | Super Series | Roadmaster Series |
| Wheelbase (all models) | 122" | 122" | 127" | 127" |
| Tread - front | 59" | 59" | 59" | 59" |
| Tread - rear | 59" | 59" | 62.2" | 62.2" |
| Overall length with bumpers | 206.6" | 206.6" | 215.9" | 215.9" |
| Overall maximum width | 76" | 76" | 80" | 80" |
| Height (at normal load) | 60.2"** | 60.5" | 62.4" | 62.6" |
| Minimum road clearance | 62.2" | 62.5" | 62.5" | 62.7" |
| Shipping weight* - Synchromesh | 3,742 pounds | - | - | - |
| Shipping weight* - Dynaflow | 3,866 pounds | 3,897 pounds | 4,239 pounds | 4,278 pounds |
| Location of engine number | Stamped on extension of top face of block on left hand of cylinders below cylinder head | Stamped on extension of top face of block on left hand of cylinders below cylinder head | Stamped on extension of top face of block on left hand of cylinders below cylinder head | Stamped on extension of top face of block on left hand of cylinders below cylinder head |
| Location of serial number | Plate of left front pillar and stamped on left side rail - near front | Plate of left front pillar and stamped on left side rail - near front | Plate of left front pillar and stamped on left side rail - near front | Plate of left front pillar and stamped on left side rail - near front |
| Engine - General | Special Series | Century Series | Super Series | Roadmaster Series |
| Engine type and make | Buick 90 degree V8 | Buick 90 degree V8 | Buick 90 degree V8 | Buick 90 degree V8 |
| Valve arrangement | In-head | In-head | In-head | In-head |
| Bore and stroke | 3.625" x 3.2" | 4" x 3.2" | 4" x 3.2" | 4" x 3.2" |
| Piston displacement | 264 cui | 322 cui | 322 cui | 322 cui |
| Cylinder numbering, front to rear - left | 2-4-6-8 | 2-4-6-8 | 2-4-6-8 | 2-4-6-8 |
| Cylinder numbering, front to rear - right | 1-3-5-7 | 1-3-5-7 | 1-3-5-7 | 1-3-5-7 |
| Firing order | 1-2-7-8-4-5-6-3 | 1-2-7-8-4-5-6-3 | 1-2-7-8-4-5-6-3 | 1-2-7-8-4-5-6-3 |
| Compression ratio | 8.4 | 9.0 | 9.0 | 9.0 |
| Mounting points | 2 Front, 1 Rear | 2 Front, 1 Rear | 2 Front, 1 Rear | 2 Front, 1 Rear |
| Taxable horsepower | 42.05 | 51.2 | 51.2 | 51.2 |
| Maximum horsepower*** | 188 @ 4,800 rpm | 236 @ 4,600 rpm | 236 @ 4,600 rpm | 236 @ 4,600 rpm |
| Maximum torque*** | 256 lb.-ft. @ 2,400 rpm | 330 lb.-ft. @ 3,000 rpm | 330 lb.-ft. @ 3,000 rpm | 330 lb.-ft. @ 3,000 rpm |
| Engine - Block or Crankcase | Special Series | Century Series | Super Series | Roadmaster Series |
| Material | Special Alloy Cast Iron | Special Alloy Cast Iron | Special Alloy Cast Iron | Special Alloy Cast Iron |
| Design | Deep-flange, Rib-reinforced | Deep-flange, Rib-reinforced | Deep-flange, Rib-reinforced | Deep-flange, Rib-reinforced |
| Engine - Camshaft | Special Series | Century Series | Super Series | Roadmaster Series |
| Material | Forged Steel | Forged Steel | Forged Steel | Forged Steel |
| Bearing number and material | 5, Steel-backed Babbitt | 5, Steel-backed Babbitt | 5, Steel-backed Babbitt | 5, Steel-backed Babbitt |
| Type and make of drive | Chain, Link Belt | Chain, Link Belt | Chain, Link Belt | Chain, Link Belt |
| Engine - Connecting Rods | Special Series | Century Series | Super Series | Roadmaster Series |
| Material | Forged Steel | Forged Steel | Forged Steel | Forged Steel |
| Bearing Material | Steel-backed Moraine 400 | Steel-backed Moraine 400 | Steel-backed Moraine 400 | Steel-backed Moraine 400 |
| Effective bearing length | .881" | .881" | .881" | .881" |
| Rod length, center to center | 6" | 6" | 6" | 6" |
| Engine - Cooling System | Special Series | Century Series | Super Series | Roadmaster Series |
| Cooling system type | Water Pump Pressure | Water Pump Pressure | Water Pump Pressure | Water Pump Pressure |
| Radiator Pressure Control Valve | 7 lbs. | 7 lbs. | 7 lbs. | 7 lbs. |
| Water Temperature Control | Thermostat and By-pass | Thermostat and By-pass | Thermostat and By-pass | Thermostat and By-pass |
| Circulation starts to open at | 157-162 °F | 157-162 °F | 157-162 °F | 157-162 °F |
| Water pump type | Centrifugal | Centrifugal | Centrifugal | Centrifugal |
| Water pump bearing type | Sealed, double row ball bearing | Sealed, double row ball bearing | Sealed, double row ball bearing | Sealed, double row ball bearing |
| By-pass recirculation | Internal | Internal | Internal | Internal |
| Radiator core type | Vee Cellular | Vee Cellular | Vee Cellular | Vee Cellular |
| Water all around cylinders | Yes | Yes | Yes | Yes |
| Number of fan blades | 4 | 4 | 4 | 4 |
| Fan diameter | 18" | 18" | 18" | 18" |
| Cooling system capacity - Synchromesh less heater | 16.5 qts. | 16.5 qts. | 16.5 qts. | - |
| Cooling system capacity - Synchromesh with heater | 18.0 qts. | 18.0 qts. | 18.0 qts. | - |
| Cooling system capacity - Dynaflow less heater | 18.5 qts. | 18.5 qts. | 18.5 qts. | 18.5 qts. |
| Cooling system capacity - Dynaflow with heater | 20.0 qts. | 20.0 qts. | 20.0 qts. | 20.0 qts. |
| Engine - Crankshaft | Special Series | Century Series | Super Series | Roadmaster Series |
| Material | Forged Steel | Forged Steel | Forged Steel | Forged Steel |
| Weight | 56.7 pounds | 56.7 pounds | 56.7 pounds | 56.7 pounds |
| Main bearing material | Steel-backed Durex 100 A | Steel-backed Durex 100 A | Steel-backed Durex 100 A | Steel-backed Durex 100 A |
| Main bearing journal diameter and eff. Length - No. 1 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 |
| Main bearing journal diameter and eff. Length - No. 2 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 |
| Main bearing journal diameter and eff. Length - No. 3 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 |
| Main bearing journal diameter and eff. Length - No. 4 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 |
| Main bearing journal diameter and eff. Length - No. 5 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 | 2.4985 x 1.250 |
| Engine - Exhaust System | Special Series | Century Series | Super Series | Roadmaster Series |
| Exhaust system type | Single with cross-over | Single with cross-over | Single with cross-over | Single with cross-over |
| Muffler Type | Dynamic Flow | Dynamic Flow | Dynamic Flow | Dynamic Flow |
| Engine - Fuel System | Special Series | Century Series | Super Series | Roadmaster Series |
| Fuel tank capacity | 19 galons | 19 galons | 19 galons | 19 galons |
| Fuel pump type | Mechanical | Mechanical | Mechanical | Mechanical |
| Vacuum booster | Standard | Standard | Standard | Standard |
| Fuel filter type and location | Sinterized Bronze Element at Carburetor | Sinterized Bronze Element at Carburetor | Sinterized Bronze Element at Carburetor | Sinterized Bronze Element at Carburetor |
| Carburetor type | 2-barrel Downdraft | 4-barrel Downdraft | 4-barrel Downdraft | 4-barrel Downdraft |
| Intake manifold heat control | Automatic | Automatic | Automatic | Automatic |
| Automatic choke type | Integral | Integral | Integral | Integral |
| Standard air cleaner type | Heavy Duty Oil Bath | Heavy Duty Oil Bath | Heavy Duty Oil Bath | Heavy Duty Oil Bath |
| Engine - Lubrication System | Special Series | Century Series | Super Series | Roadmaster Series |
| Main bearing lubrication | Pressure | Pressure | Pressure | Pressure |
| Connecting rod lubrication | Pressure | Pressure | Pressure | Pressure |
| Piston pin lubrication | Splash | Splash | Splash | Splash |
| Camshaft lubrication | Pressure | Pressure | Pressure | Pressure |
| Tappet lubrication | Pressure | Pressure | Pressure | Pressure |
| Timing chain lubrication | Drip from front camshaft bearing | Drip from front camshaft bearing | Drip from front camshaft bearing | Drip from front camshaft bearing |
| Cylinder wall lubrication | Splash and Nozzle | Splash and Nozzle | Splash and Nozzle | Splash and Nozzle |
| Oil pump type | Gear | Gear | Gear | Gear |
| Normal oil pressure | 35 lb. @ 1,600 rpm | 35 lb. @ 1,600 rpm | 35 lb. @ 1,600 rpm | 35 lb. @ 1,600 rpm |
| Type air intake | Stationary | Stationary | Stationary | Stationary |
| Standard oil filter type | Full Flow | Full Flow | Full Flow | Full Flow |
| Capacity of oil reservoir | 6 qts. | 6 qts. | 6 qts. | 6 qts. |
| Engine - Pistons | Special Series | Century Series | Super Series | Roadmaster Series |
| Material | Aluminum Alloy | Aluminum Alloy | Aluminum Alloy | Aluminum Alloy |
| Description and finish | Cam ground - Transverse Slot - Divorced Full Skirt - Anodized | Cam ground - Transverse Slot - Divorced Full Skirt - Anodized | Cam ground - Transverse Slot - Divorced Full Skirt - Anodized | Cam ground - Transverse Slot - Divorced Full Skirt - Anodized |
| Weight (piston only) | 16.25 oz. | 19.95 oz. | 19.95 oz. | 19.95 oz. |
| Engine - Piston Rings | Special Series | Century Series | Super Series | Roadmaster Series |
| Compression rings per cylinder | 2 | 2 | 2 | 2 |
| Compression ring material | Cast Iron | Cast Iron | Cast Iron | Cast Iron |
| Oil rings per cylinder | 1 | 1 | 1 | 1 |
| Oil ring material | Steel | Steel | Steel | Steel |
| Number of rings above piston pin | 3 | 3 | 3 | 3 |
| Engine - Valve System | Special Series | Century Series | Super Series | Roadmaster Series |
| Hydraulic lifters | All Engines | All Engines | All Engines | All Engines |
| Operating tappet clearance | None | None | None | None |
| Intake and exhaust valve material | Nickel-Chrome Alloy Steel | Nickel-Chrome Alloy Steel | Nickel-Chrome Alloy Steel | Nickel-Chrome Alloy Steel |
| Intake and exhaust valve overall length | 4.704" | 4.704" | 4.704" | 4.704" |
| Intake valve head diameter | 1.750" | 1.750" | 1.750" | 1.750" |
| Exhaust valve head diameter | 1.375" | 1.375" | 1.375" | 1.375" |
| Intake and exhaust valve seat angle | 45 degrees | 45 degrees | 45 degrees | 45 degrees |
| Intake valve lift | .358" | .378" | .378" | .378" |
| Exhaust valve lift | .350" | .378" | .378" | .378" |
| Electrical - Ignition System | Special Series | Century Series | Super Series | Roadmaster Series |
| Coil and distributor make | Delco Remy | Delco Remy | Delco Remy | Delco Remy |
| Spark plug make and model | AC 44-5 | AC 44-5 | AC 44-5 | AC 44-5 |
| Spark plug gap | .030"-.035" | .030"-.035" | .030"-.035" | .030"-.035" |
| Spark plug protection | Neoprene Boot and Sheet Metal Cover | Neoprene Boot and Sheet Metal Cover | Neoprene Boot and Sheet Metal Cover | Neoprene Boot and Sheet Metal Cover |
| Electrical supression | Distributor, Coil, Generator, Voltage Regulator | Distributor, Coil, Generator, Voltage Regulator | Distributor, Coil, Generator, Voltage Regulator | Distributor, Coil, Generator, Voltage Regulator |
| Electrical - Starting System | Special Series | Century Series | Super Series | Roadmaster Series |
| Starting motor make | Delco Remy | Delco Remy | Delco Remy | Delco Remy |
| Engine cranking speed | Appr. 160 rpm | Appr. 160 rpm | Appr. 160 rpm | Appr. 160 rpm |
| Motor control switch, 3-position | Selenoid | Selenoid | Selenoid | Selenoid |
| Motor starting procedure | Turn on ignition - Depress accelerator | Turn on ignition - Depress accelerator | Turn on ignition - Depress accelerator | Turn on ignition - Depress accelerator |
| Electrical - Supply System | Special Series | Century Series | Super Series | Roadmaster Series |
| Battery make | Delco Remy | Delco Remy | Delco Remy | Delco Remy |
| Battery rating | 12-volt | 12-volt | 12-volt | 12-volt |
| Battery location | Left front fender skirt, under hood | Left front fender skirt, under hood | Left front fender skirt, under hood | Left front fender skirt, under hood |
| Battery terminal grounded | Negative | Negative | Negative | Negative |
| Generator make | Delco Remy | Delco Remy | Delco Remy | Delco Remy |
| Generator type | Shunt | Shunt | Shunt | Shunt |
| Regulator make | Delco Remy | Delco Remy | Delco Remy | Delco Remy |
| Regulator type | Voltage and Current Control | Voltage and Current Control | Voltage and Current Control | Voltage and Current Control |
| Electrical - Horns, Lights | Special Series | Century Series | Super Series | Roadmaster Series |
| Dual horn type | Vibrator | Vibrator | Vibrator | Vibrator |
| Outside and instrument panel lighting | Unified single-switch control | Unified single-switch control | Unified single-switch control | Unified single-switch control |
| Drive Units - Propeller Shaft | Special Series | Century Series | Super Series | Roadmaster Series |
| Number and type | Singe, enclosed in Torque Tube | Singe, enclosed in Torque Tube | Singe, enclosed in Torque Tube | Singe, enclosed in Torque Tube |
| Drive thrust taken through | Torque Tube | Torque Tube | Torque Tube | Torque Tube |
| Torque thrust taken through | Torque Tube | Torque Tube | Torque Tube | Torque Tube |
| Drive Units - Rear Axle | Special Series | Century Series | Super Series | Roadmaster Series |
| Type and gearing | Semi-Floating, Hypoid | Semi-Floating, Hypoid | Semi-Floating, Hypoid | Semi-Floating, Hypoid |
| Gear ratio, Synchromesh | 3.9 | 3.9 | 3.9 | - |
| Gear ratio, Dynaflow | 3.6 | 3.4 | 3.4 | 3.4 |
| Drive Units - Dynaflow Transmission | Special Series | Century Series | Super Series | Roadmaster Series |
| Trade name | Variable Pitch Dynaflow | Variable Pitch Dynaflow | Variable Pitch Dynaflow | Variable Pitch Dynaflow |
| Transmission type | Torque Converter with Gears | Torque Converter with Gears | Torque Converter with Gears | Torque Converter with Gears |
| Acceleration shifting | Stator blades shift to "performance" pitch past full throttle, but no gear-change as in conventional dirves | Stator blades shift to "performance" pitch past full throttle, but no gear-change as in conventional dirves | Stator blades shift to "performance" pitch past full throttle, but no gear-change as in conventional dirves | Stator blades shift to "performance" pitch past full throttle, but no gear-change as in conventional dirves |
| Governor shifting involuntary | None at any speed | None at any speed | None at any speed | None at any speed |
| Downshift through range selector | Not recommended over 40 mph | Not recommended over 40 mph | Not recommended over 40 mph | Not recommended over 40 mph |
| Mechanical lockup in direct drive | None | None | None | None |
| Type of transmission cooling | Water-cooled | Water-cooled | Water-cooled | Water-cooled |
| Total oil capacity | 20 | 20 | 20 | 20 |
| Drive Units - Synchromesh Transmission | Special Series | Century Series | Super Series | Roadmaster Series |
| Clutch make and type | Buick, dry plate | Buick, dry plate | Buick, dry plate | - |
| Clutch facing material | Woven | Woven | Woven | - |
| Clutch inside and outside diameters | 6-10" | 6.5-10.5" | 6.5-10.5" | - |
| Total effective facing area | 100.6 sq. in. | 106.8 sq. in. | 106.8 sq. in. | - |
| Number of forward speeds | 3 | 3 | 3 | - |
| Helical gears | In all speeds | In all speeds | In all speeds | - |
| Lubricant capacity | 1.75 | 2.5 | 2.5 | - |
| Chassis - Brakes, Service & Parking | Special Series | Century Series | Super Series | Roadmaster Series |
| Service brake type | Hydraulic - Internal Expanding | Hydraulic - Internal Expanding | Hydraulic - Internal Expanding | Hydraulic - Internal Expanding |
| Power brake with vacuum booster | Optional all Series with Dynaflow | Optional all Series with Dynaflow | Optional all Series with Dynaflow | Optional all Series with Dynaflow |
| Effective lining area | 184.6 sq. in. | 207.5 sq. in. | 207.5 sq. in. | 219.0 sq. in. |
| Brake drum material | Cast iron | Cast iron | Cast iron | Cast iron |
| Brake drum diameter, front and rear | 12" | 12" | 12" | 12" |
| Brake lining material | Molded Extruded | Molded Extruded | Molded Extruded | Molded Extruded |
| Brake lining width and thickness, front | 2.25 x .187" | 2.25 x .187" | 2.25 x .187" | 2.50 x .250" |
| Brake lining width and thickness, rear | 1.75 x .187" | 2.25 x .187" | 2.25 x .187" | 2.25 x .187" |
| Parking brake operates through | Rear service brakes | Rear service brakes | Rear service brakes | Rear service brakes |
| Parking brake is set through | Foot pedal at left | Foot pedal at left | Foot pedal at left | Foot pedal at left |
| Parking brake is released through | Knob under instrument panel | Knob under instrument panel | Knob under instrument panel | Knob under instrument panel |
| Parking brake warning light, automatic | Optional | Optional | Optional | Standard |
| Chassis - Frame | Special Series | Century Series | Super Series | Roadmaster Series |
| Type and description | Double drop, channel X center cross member, box type front cross member | |||
| Chassis - Steering | Special Series | Century Series | Super Series | Roadmaster Series |
| Steering type used | Mechanical**** | Mechanical**** | Power | Power |
| Steering wheel diameter | 18" | 18" | 18" | 18" |
| Steering gear type, both mechanical and power | Ball bearing worm and nut | Ball bearing worm and nut | Ball bearing worm and nut | Ball bearing worm and nut |
| Standard steering gear ratio | 26.7:1 | 26.7:1 | 24.1:1 | 24.1:1 |
| Optional steering gear ratio with Power Steering | 24.1:1 | 24.1:1 | 24.1:1 | 24.1:1 |
| Turn diameter, curb to curb | 41.6 | 41.6 | 43.0 | 43.0 |
| Steering linkage type | Parallelogram | Parallelogram | Parallelogram | Parallelogram |
| Linkage tie rods | Two, Transverse | Two, Transverse | Two, Transverse | Two, Transverse |
| Chassis - Suspension, Front | Special Series | Century Series | Super Series | Roadmaster Series |
| Front suspension type | Independent with Coil Springs | Independent with Coil Springs | Independent with Coil Springs | Independent with Coil Springs |
| Front coil spring material | High Carbon Silicon Manganese Steel | High Carbon Silicon Manganese Steel | High Carbon Silicon Manganese Steel | High Carbon Silicon Manganese Steel |
| Shock absorbers | Direct Type | Direct Type | Direct Type | Direct Type |
| Front stabilizer | Link type mounted in rubber | Link type mounted in rubber | Link type mounted in rubber | Link type mounted in rubber |
| Chassis - Suspension, Rear | Special Series | Century Series | Super Series | Roadmaster Series |
| Rear suspension type | Coil Springing, Drive and Torque taken through Torque Tube | Coil Springing, Drive and Torque taken through Torque Tube | Coil Springing, Drive and Torque taken through Torque Tube | Coil Springing, Drive and Torque taken through Torque Tube |
| Rear coil spring material | High Carbon Silicon Manganese Steel | High Carbon Silicon Manganese Steel | High Carbon Silicon Manganese Steel | High Carbon Silicon Manganese Steel |
| Shock absorbers | Lever Type | Lever Type | Lever Type | Lever Type |
| Rear sidesway control | Tubular steel radius rod mounted in rubber | Tubular steel radius rod mounted in rubber | Tubular steel radius rod mounted in rubber | Tubular steel radius rod mounted in rubber |
| Chassis - Wheels and Tires | Special Series | Century Series | Super Series | Roadmaster Series |
| Wheel type | Disc | Disc | Disc | Disc |
| Wheel size | 15 x 5.50 | 15 x 6.00 | 15 x 6.00 | 15 x 6.00 |
| Tire type | Tubeless | Tubeless | Tubeless | Tubeless |
| Tire size | 7.10-15***** | 7.60-15 | 7.60-15 | 8.00-15 |
| Tire revs. per mile at 30 mph | 750 | 735 | 735 | 723 |
| Tire pressure, front and rear, cold | 24 | 24 | 24 | 24 |
| Visibility - Glass Area, Wipers | Special Series | Century Series | Super Series | Roadmaster Series |
| Windshield (4-door sedan) | 1,179.5 sq. in. | 1,179.5 sq. in. | 1,207.7 sq. in. | 1,207.7 sq. in. |
| Rear window (4-door sedan) | 1,045.8 sq. in. | 1,045.8 sq. in. | 979.5 sq. in. | 979.5 sq. in. |
| Total area (4-door sedan) | 3,888.4 sq. in. | 3,888.4 sq. in. | 4,048.9 sq. in. | 4,048.9 sq. in. |
| Windshield wiper make and type | Trico, Vacuum | Trico, Vacuum | Trico, Vacuum | Trico, Cam-o-matic |