Engine and Fuel system
The 924 Engine.
The 924 engine is a radical departure from previous Porsche designs, namely it is watercooled and mounted at the front of the vehicle. The engine is actually the same 2.0L engine as used in the Audi 100 with some minor modifications.
Engine Specifications (Australian and European cars)
Type: Water cooled, single overhead camshaft, 4 cylinder, 4 stroke engine.
Cylinder Head: Light Alloy.
Cylinder Block: Cast Iron.
Crankshaft: Forged Steel.
Pistons: Cast Light Alloy.
Cooling: Pressurized water/ethylene glycol coolant, electric fan with thermo switch.
Compression: 9.3:1
Horsepower: 125HP at 5800 rpm (92 kW)
Torque: 121.7ft-lb at 3500 rpm (16.8m-kg)
Maximum rpm: 6500
Fuel System
All european 924's are fitted with Bosch K-Jetronic (k-tronic) continuous injection system (CIS) fuel injection. Although known as the k-tronic system it does not depend on electronics, but on the passage of air through a sensor plate. The system provides constant fuel output at the fuel injectors which is varied by the position of the sensor plate in the air stream. As air passes through the airflow meter, the sensor plate is lifted from rest. The sensor plate is connected to a pneumatic arm and the angle at which the sensor plate becomes stable depends on the airflow which is governed by the engine speed. The sensor plate pneumatic arm directly operated the fuel metering unit. The sensor plate arm moves a plunger in the metering bores of the metering unit (one for each injector) increasing or decreasing the injector fuel flow as required. The bores are specially machined to provide different air/fuel mixtures at different engine speeds. The Bosch k-tronic system is a most reliable and easy to trouble-shoot system and is central to the 924's well known reliability.