Introduction
Ford’s Barra 240T was a turbocharged 4.0-litre inline six-cylinder petrol engine that was introduced in the Ford BA Falcon XR6 Turbo in October 2002. While the Barra 240T shared may attributes with the naturally aspirated Barra 240T engine on which it was based, key differences included:
- A Garrett GT3582R turbocharger which provided peak boost pressure of 6 psi (0.413 bar);
- Dished bowl pistons – with fully floating gudgeon pins – for a compression ratio of 8.7:1;
- Increased fuel delivery pressure (4.0 bar, compared to 2.4 bar);
- More heat resistant exhaust valves; and,
- Heat shields to protect components such as the steering column assembly and the under floor area above the three-inch dump pipe and the catalysts.
Due to its forced induction, however, the Barra 240T engine did not have a dual resonance inlet manifold like the Barra 240T.
| Model | Engine | Trans. | Peak power | Peak torque | Years |
|---|---|---|---|---|---|
| Ford BA Falcon XR6 Turbo | 4.0-litre petrol I6 | 5sp man., 4sp auto |
240kW at 5250rpm | 450Nm at 2000-4500rpm | 2002-05 |
Block
Like the Barra 240T, the Barra 240T engine had a cast iron block with 92.26 mm bores and a 99.31 mm stroke for a capacity of 3984 cc. Similarly, the Barra 240T block had cross-bolted main bearing caps to increase rigidity and a cross-bolted alloy sump.
Cylinder head
The Barra 240T engine had a gravity-cast, aluminium alloy cylinder head which was mounted on a single layer steel (SLS) sheet metal gasket. The water jacket for the Barra 240T engine featured deflection vanes to squeeze coolant past hot spots – such as the exhaust valve seats – at higher velocities to achieve more even temperatures throughout the cylinder head.
Pistons and compression
Due to its forced induction, the tops of the pistons for the Barra 240T had a ‘dished bowl’ shape which lowered the compression ratio to 8.7:1 (compared to 9.7:1 for the Barra 240T). Furthermore, fully floating gudgeon pins were used to connect the piston to the connecting rod.
Garrett turbocharger
The Barra 240T engine had a Garrett GT3582R turbocharger which provided maximum boost pressure of 6 psi (0.413 bar). The turbocharger consisted of two elements, a turbine and a compressor, which were both installed on a single shaft. The ball bearings were supplied with engine oil from the oil supply tube which was then returned to the oil pan via the oil return pipe. The turbocharger housing received coolant from the engine cooling system.
The turbine was mounted on the exhaust manifold and used the flow of exhaust gases to drive the compressor. The compressor would then feed air to the engine’s air intake via the air-to-air intercooler which regulated the temperature of the charged air to maintain boost pressure.
The Powertrain Control Module (PCM) used a boost pressure sensor (BPS) to monitor the boost pressure of the turbocharger. Based on engine load, temperature and engine speed, boost pressure was determined by the operation of a single by-pass wastegate valve which controlled how much exhaust gas was directed to the turbine and, therefore, the turbine’s speed. In turn, the wastegate valve was operated by an actuator which had a diaphragm and used regulated air pressure.
Intake air pressure was further controlled by a blow-off valve which would dump excess pressure into the low pressure side of the intake system when the throttle was closed. The blow-off valve was actuated by intake manifold pressure, via a rubber hose from the intake manifold.
Camshafts and valvetrain
The Barra 240T engine had double overhead camshafts that were driven by a single-stage roller chain. To minimise weight and improve durability at higher engine speeds, the camshafts were roll-forged and had bored centres. The four valves per cylinder were actuated by roller finger followers and a clip held the hydraulic lash adjusters to the rockers for durability. To limit in-chamber tumble and provide good seating, the valves had a domed head and no lip. It is understood that the Barra 240T shared key specifications with the Barra 240T engine (see table below).
Variable Cam Timing (VCT)The Barra 240T engine had a vane-type VCT phaser – produced by Aisin – on each camshaft that provided continual variable adjustment within a 60 degree range (10 degrees advanced or 50 degrees retarded from the initial pin lock position). Each camshaft phaser was hydraulically controlled via an oil control valve that was mounted on top of it. However, the Barra 240T engine had Ford’s ‘Dual Equal Phase Shifting’ (DEPS) VCT system whereby the intake and exhaust camshafts could only be controlled synchronously. As such, intake and exhaust camshaft timing could only be advanced or retarded by the same degree simultaneously, and not independently. Valve timing for the initial, advanced and retarded camshaft settings are understood to be the same as the Barra 240T engine and are given in the tables below. Based on these timings, valve overlap was 25 degrees, intake duration was 251 degrees and exhaust duration was 246 degrees. At idle, the camshaft timing could be advanced by 10 degrees from the pin lock position for smoother running. On low throttle openings, however, the system could retard timing by as much as 50 degrees from the pin lock position to reduce fuel consumption and lower exhaust emissions via internal exhaust gas recirculation.
Injection and ignitionThe Barra 240T engine had an electronically-controlled sequential fuel injection system with peak fuel delivery pressure of 4.0 bar. The ‘speed density’ fuel injection system used the engine speed, intake air temperature and manifold absolute pressure sensors to calculate intake air mass and therefore the fuel required to be injected for combustion. This quantity of fuel was then adjusted according to feedback information from the Heated Oxygen (HEGO) sensor, providing close loop control of fuel injection. The Barra 240T engine had distributorless, coil-on-plug ignition with individual coils mounted above the spark plug. The long-life spark plug was positioned in the centre of the combustion chamber roof between the four valves. The Barra 240T engine had a 1-5-3-6-2-4 firing order. While a knock sensor enabled the engine to run on regular unleaded fuel, 95 RON premium unleaded petrol was recommended. Internal Exhaust Gas Recirculation (EGR)The Barra 240T engine complied with Euro II emission standards and had an internal exhaust gas recirculation system whereby late closing of the exhaust valves – during the downward induction stroke – would cause some of the unburned exhaust gas in the extractors to return to the intake. 
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