Ford Barra 195 I6 engine – Australian Car.Reviews

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Introduction

Ford’s Barra 195 was a naturally aspirated, 4.0-litre inline six-cylinder petrol engine that was introduced in the Ford FG Falcon in 2008. Replacing Ford’s Barra 190 engine, changes for the Barra 195 included:

A redesigned cylinder head; and,
A new split plenum intake manifold.

On 90 RON regular unleaded petrol, the Barra 195 engine produced peak power and torque of 195 kW at 6000 rpm and 391 Nm at 3250 rpm, respectively. On 95 RON unleaded petrol, however, peak outputs increased to 198 kW and 409 Nm.
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Model	Engine	Trans.	Peak power	Peak torque	Years
Ford FG Falcon	4.0-litre petrol I6	6sp man., 5sp auto, 6sp auto	195kW at 6000rpm	391Nm at 3250rpm	2008-14
Ford FG X Falcon	4.0-litre petrol I6	6sp man., 6sp auto	195kW at 6000rpm	391Nm at 3250rpm	2011-16
Ford SZ Territory	4.0-litre petrol I6	6sp auto	195kW at 6000rpm	391Nm at 3250rpm	2014-16

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Block

Like Ford’s other Barra engines, the Barra 195 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 195 block had cross-bolted main bearing caps to increase rigidity and a cross-bolted alloy sump.

Cylinder head

The Barra 195 engine had a gravity-cast, aluminium alloy cylinder head which was mounted on a single layer steel (SLS) sheet metal gasket. For the Barra 195 engine, a redesigned ‘fast burn’ cylinder head was introduced which had revised intake port profiling and new combustion chamber geometry to increase swirl for faster combustion. According to Ford, the higher turbulence enabled additional camshaft retard at part throttle due to an improved lean limit, thereby reducing pumping losses and improving fuel efficiency.

The water jacket for the Barra 195 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.

Camshafts and valvetrain

The Barra 195 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 Barra 195 engine had four valves per cylinder that were actuated by roller finger followers; hydraulic lash adjusters maintained zero valve clearance, while a clip held the lash adjuster to the rocker for durability. To limit in-chamber tumble and provide good seating, the valves had a domed head and no lip. Valvetrain specifications for the Barra 195 – given in the table below – are understood to be the same as the Barra 190 engine.
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Barra 195 valvetrain specifications
Rocker arm ratio	2.04:1
Camshaft lobe lift (intake and exhaust)	5.39 mm
Valve lift (intake and exhaust)	11.00 mm
Intake valve diameter	35.0 mm
Exhaust valve diameter	32.0 mm

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Dual Independent Variable Cam Timing (DI-VCT)

The Barra 195 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.

The variable cam timing system for the Barra 195 engine was Ford’s ‘Dual Independent Phase Shifting’ (DIPS) which enabled the intake and exhaust camshafts to be varied independently of each other. In contrast, the Barra 182 engine had Dual Equal Phase Shifting (DEPS) in which the intake and exhaust camshafts could only be advanced or retarded by the same degree synchronously such that valve overlap was a constant 25 degrees.

Valve timing for the Barra 195 engine is understood to be the same as the Barra 190 engine and is given in the tables below. From these, valve overlap could be varied from -35 degrees to 85 degrees, intake duration was 256 degrees and exhaust duration was 256 degrees. Furthermore,

On low throttle openings, timing would be retarded by up to 50 degrees to improve fuel economy;
At idle, the intake camshaft was retarded by 18 degrees for improved combustion and a stable idle; and,
At higher loads, timing would be advanced for greater power.

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Barra 195 engine – valve timing: pin lock position
Intake	Open	27.5° BTDC
Intake	Close	48.5° ABDC
Exhaust	Open	78.5° BBDC
Exhaust	Close	2.5° BTDC

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Barra 195 engine – valve timing: 10 degrees advanced
Intake	Open	37.5° BTDC
Intake	Close	38.5° ABDC
Exhaust	Open	88.5° BBDC
Exhaust	Close	12.5° BTDC

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Barra 195 engine – valve timing: 50 degrees retarded
Intake	Open	22.5° ATDC
Intake	Close	98.5° ABDC
Exhaust	Open	28.5° BBDC
Exhaust	Close	47.5° ATDC

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Intake

The Barra 195 engine introduced a new ‘dual mode, split plenum intake manifold’. The purpose of the split plenum intake manifold was to separate intake pulses in the manifold according to the firing order of the cylinders – this minimised interference of one cylinder’s pressure waves with those of another, improving mid-range torque.

It is understood that the term ‘dual mode’ was used to refer Ford’s ‘Intake Manifold Charge Control’ or IMCC system which used a butterfly valve in the intake runner for each cylinder that was controlled by the Powertrain Control Module (PCM) via a vacuum actuator. In normal operation, the butterfly valves were closed to create a longer intake path to increase the pulsing effect of the intake air, draw more air into the cylinder and increase torque. At higher engine speeds (i.e. above approximately 3800 rpm for the Barra 182 and Barra 190), the butterfly valves would to create a shorter intake path which reduced intake resistance and allowed a greater volume of air into the cylinder for top-end power.

The Barra 195 intake manifold incorporated a new throttle body and fuel rail assembly; like the Barra 182 and Barra 190, the Barra 195 engine had electronic ‘drive-by-wire’ throttle control. Furthermore, the intake manifold was made of composite materials, including glass fibre reinforced nylon (30 per cent grade), to achieve a 4 kg mass reduction.

For the Barra 195 engine, the airbox and intake duct surfaces were stiffened and ribbed to minimise the transmission of air flow noise, while four resonators were tuned to remove intake system resonance noise.

Injection and ignition

The Barra 195 engine had an electronically-controlled sequential fuel injection. 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 195 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. Like the Barra 190 engine, each spark plug had a 0.5 mm finewire centre electrode and platinum pad ground electrodes.

As introduced in the Barra 190, the ignition system for the Barra 195 featured adaptive and variable dwell (the time required to charge the ignition coil) for more efficient ignition control. Specifically,

Adaptive dwell accounted for battery voltage and the temperature of the coil windings in the ignition system to provide a more reliable, consistent charge; and,
Variable dwell provided maximum coil energy when high voltages were required (e.g. wide open throttle) and minimum coil energy when cruising or at idle.

The Barra 195 engine had a compression ratio of 10.3:1 and 1-5-3-6-2-4 firing order.

Knock sensing and spark correction

Like the Barra 190, the Barra 195 engine had twin knock sensors which, according to Ford, enabled a change in ignition timing strategy for more accurate spark control, improved fuel economy and greater refinement. Specifically, the Powertrain Control Module had four forms of spark control:

Individual/averaged spark correction: a performance mode which used 50 per cent of the individual cylinder correction and 50 per cent of engine average spark correction for more consistent performance at higher engine speeds and under heavy loads;
Individual ‘fast only’ spark correction: reacted to detonation noise and retarded the spark for the next firing event on the same cylinder. This method provided optimum fuel efficiency because spark was only retarded when detonation was detected by the system;
Individual slow/fast spark correction: applied in addition to the ‘fast only’ mode, slow correction recorded the spark advance used on previous combustion cycles and gradually reduced spark advance if knock was not detected for a few seconds, providing greater refinement; and,
No spark correction: used at low engine loads when detonation was not possible. As a result, optimum spark timing was applied.

If using premium unleaded petrol, spark advance enabled greater power and lower fuel consumption.