Porsche 911T 2.4L Engine 1973.5 Type 911/91

Offered here is a 1973.5 Porsche 911T Type 911/91 engine, a 2.4-liter flat-six originally built for the U.S.-market 911T. This late-production example represents the transition from mechanical fuel injection to the Bosch CIS (Continuous Injection System), which became a defining feature of mid-year 911s. The engine retains a largely complete setup, including its Bosch fuel injection system, ignition components, alternator, cooling fan, stainless-steel CIS airbox, heat exchangers, and muffler.

The seller reports that the engine was running when removed approximately twelve years ago and has been stored indoors since. It remains a well-preserved example of Porsche’s early CIS-equipped flat-six, ideal for restoration or period-correct replacement in a 1973.5 911T.

Technical Specifications

• Engine Type: 911/91

• Displacement: 2,341cc (2.4 liters)

• Configuration: Flat-six (horizontally opposed)

• Bore x Stroke: 84mm x 70.4mm

• Compression Ratio: 7.5:1 (factory rating)

• Fuel System: Bosch CIS fuel injection

• Ignition: Bosch electronic ignition components

• Cooling System: Air-cooled, with 11-blade aluminum cooling fan

• Power Output (factory-rated): 140 hp @ 5,600 rpm

• Torque (factory-rated): 148 lb-ft @ 4,000 rpm

• Construction: Magnesium crankcase, aluminum cylinder heads

Condition & Included Components

• Condition: Used; removed from a running car ~12 years ago, stored since

• Case: Original magnesium case, stamped Type 911/91

• Fan Shroud & Tins: Black finish

• Fuel System: Complete Bosch CIS with stainless-steel airbox

• Cooling System: 11-blade fan, alternator, and shroud intact

• Exhaust: Factory-style heat exchangers and muffler included

• Other Components: Flywheel, clutch, and ignition distributor installed

Compatibility

Suitable for:

• 1973.5 Porsche 911T (U.S. Market)

• Ideal for use in period-correct restorations or air-cooled Porsche engine swaps requiring a complete 2.4L CIS-equipped flat-six.

This Type 911/91 engine is a 2,341cc flat-six originally built for use in a US-market 1973.5 911T. The engine retains its Bosch fuel injection system, ignition components, alternator, cooling fan, stainless-steel CIS airbox, heat exchangers, and muffler. The seller states that the engine ran when it was removed from a car approximately twelve years ago and has been stored since.