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Porsche 550 Prototype Coupe – Specifications & Performance

Technical Specifications

Porsche 550 Prototype Coupe Specifications

The first two Porsche 550s were coupes and had slightly different specifications than the 550 Spyders that came afterwards.

Engine

  • Type 547: Four cylinder 4 cycle, box motor, air cooler, horizontal opposed, 4 overhead camshafts
  • Power: Approx 110 HP @ 6200 RPM
  • Bore: 3.35 in (85 mm)
  • Stroke: 2.59 in (66 mm)
  • Piston Displacement: 1498 cm actual, from formula cubic 1487 cm
  • Compression ratio: 9.5:1
  • Crankcase: Aluminium
  • Cylinders: Aluminium hard chromed walls
  • Cylinder head: Aluminium
  • Valves per cylinder: 1 intake, 1 exhaust
  • Valve operation: 4 camshafts driven by 2 vertical shafts
  • Crankshaft: Full roller bearing, built up
  • Pistons: Aluminium
  • Air blower drive: V-belt, crankshaft to generator shaft
  • Crankshaft-blower ratio: 1:1
  • Air volume: 1100 ltr/sec at 6200 RPM
  • Engine lubrication: Dry sump, with oil cooler and oil filter in main current
  • Firing order: 1-4-3-2
  • Distributor drive: Camshaft
  • Spark plugs: Temperature valve 260 – 280 C
  • Carburetors: Solex 40 PJJ or Weber 40 DCM
  • Muffler: 2 mufflers leading into 1 exhaust pipe
  • Clutch: Fichtel & Sachs, K 12 Porsche Special
  • Transmission: 4 forward speeds, helical gears, synchronized, 1 reverse

Gear ratio

  • 1st gear:  11:35
  • 2nd gear:  17:30 – 16:31 – 18:29
  • 3rd gear:  23:26 – 22:27 – 24:25
  • 4th gear:  27:22 – 25:24 – 26:23
  • Reverse gear: 1:3.56
  • Shifting: Ball and socket and push rods
  • Rear axle: Spiral bevel pinion, ZF lock type differential
  • Gear ratio: 8:35 – 7:31 – 7:34
  • Top speed: 124 mph

Chassis

  • Frame: Tubular, seamless steel tubing
  • Front springing: 2 transverse, 4-leaf adjustable torsion bars
  • Rear springing: 1 round torsion bar on each side
  • Shock absorbers: Fichtel & Sachs, telescopic hydraulic
  • Front: 26 x 90
  • Rear: 36 x 140 HA
  • Front wheel suspension: Longitudinal suspension arms, outside needle bearings
  • Rear wheel suspension: On oscillating half axles
  • Steering: Special worm gear with divided tie rods
  • Steering ratio: 1:14.15
  • Operating brakes: Oil hydraulic foot brakes to all four wheels
  • Parking brake: Hand lever operating cable to rear wheels
  • Brake drums: 11.0236 in (280 mm)
  • Brake lining width: 1.5748 in (40 mm)
  • Total effective surface: 115 sq in (744 sq cm)
  • Wheels: Disc
  • Rims: Aluminum
  • Tyres front:  5.00 – 16 in
  • Tyres rear: 5.25 – 16 in

Dimensions & Weight

  • Wheel base: 2101 mm / 82.7 in
  • Front tread: 1290 mm / 50.8 in
  • Rear tread: 1250 mm / 49.2 in
  • Dry weight: 550 kg / 1213 lbs

Electrical Accessories (6 volt)

  • Battery: Varta Special 6 V/70 amp
  • Starter: Bosch EED 0.4/6 L 18 / Bosch LI/GE 160/2 2500 L 10
  • Generator: (LI 20/1 P 45)
  • Voltage regulator: Bosch RS/UA 160/6/15
  • Distributor: Bosch 2 V 2/6 K 10
  • Coil: Bosch TK 6 A/5
  • Spark plugs: Bosch W 260 T 2 – W 270 T 17 or equivalent type
  • Ignition switch: Bosch SH/ZS 1/1
  • Starter switch: Kirsten 5232
  • Light switch: Kostal 7473/3 with voltage regulator
  • Beam deflector switch: Bosch SHNF 2/1
  • Blinker unit: SWF 2 x 20 watt, Type BGA
  • Blinker switch: Bosch SH 12/27 HI (2 circuit) without bulb
  • Brake light switch: Teves (On master brake cylinder)
  • Head lights: Bosch LE/YE 180/X 2/7
  • Blinker and park light: Bosch LE 14/16 N 2
  • Tail, brake, blinker & back up lights: Bosch LE 14/16 N 1
  • License plate lights: SWF EL 153-1
  • Horn: Bosch HO/EZ 32/32 D 1 or D 2

Price

  • List price (1955): US$6,800.00