1973 Porsche 911S Type 911/53 Engine & Five-Speed Manual Transaxle – MFI – Engine No. ☆6332035☆

This Porsche Type 911/53 flat-six engine paired with a five-speed manual transaxle represents a rare and historically correct drivetrain originally produced for a US-market 1973 Porsche 911S, sold new in Santa Clara, California. As one of the most desirable early-911 powerplants, the 911/53 is renowned for its mechanical fuel injection (MFI), high-revving character, and motorsport-derived engineering.

The engine was rebuilt in 1979 using 2.2-liter 911S pistons, and approximately ten years later it was installed in a 1970 Porsche 911T. Carrera-style timing chain tensioners were added in the mid-to-late 1990s—an important reliability upgrade for magnesium-case engines. The seller acquired the vehicle in 1998 and subsequently removed the engine and transaxle for long-term storage, during which oil was periodically circulated through the engine. The engine turns freely and is offered as a rebuildable core, ideal for a correct restoration or performance-oriented rebuild.

Specifications

Engine

• Engine Type: Porsche Type 911/53

• Configuration: Air-cooled flat-six

• Original Application: US-market 1973 Porsche 911S

• Engine Number: ☆6332035☆ (correct for 1973 911S)

• Fuel System: Bosch Mechanical Fuel Injection (MFI)

• MFI Pump Number: 0408 126 021

• Rebuild History:

  • Rebuilt in 1979 with 2.2L 911S pistons

  • Carrera-style chain tensioners installed (1990s)

• Case Material: Magnesium

• Rotation Status: Turns freely

Transaxle

• Transmission Type: Porsche 911/02

• Gearbox: Five-speed manual

• Serial Number: 7333855

• Original Pairing: Correct-era drivetrain for early 911S models

Included Components

• Bosch MFI pump with fuel lines

• Throttle bodies

• Intake box

• Associated wiring

• Engine and transaxle stored together since removal

Condition & Disclosures

This drivetrain is sold as a rebuildable core and is best suited for professional restoration or performance rebuilding. Known issues reported by the seller include:

• Two chipped fan impeller blades

• Noisy alternator bearings

• Rusted-through heat exchangers

• Chipped hot air regulator horn

• Dry and brittle fuel and vacuum lines

• Cracked CDI wiring harness insulation

Recent preservation steps include removal of the valve covers to lubricate camshaft lobes and valvetrain, as well as adding oil to the cylinders to prevent corrosion.

Ideal Applications

• 1973 Porsche 911S restoration (US-spec, MFI-equipped)

• Period-correct engine and gearbox rebuild

• High-end vintage Porsche performance project

• Collector seeking original-numbered 911S drivetrain

Why This Drivetrain Matters

• Correct Type 911/53 engine for 1973 US-market 911S

• Retains original Bosch MFI system, increasingly difficult to source complete

• Matching-era five-speed 911/02 transaxle included

• Documented rebuild history and long-term preservation

• Highly sought-after specification among early 911 collectors

This 1973 Porsche 911S Type 911/53 engine and five-speed transaxle offers a rare opportunity to acquire a complete, historically significant early-911 drivetrain with documented provenance—ideal for a concours-correct restoration or investment-grade rebuild.