Design

Design

Engine




The entire engine is made of aluminum.
The engine has a compact "pent-roof" designed combustion chamber and V-arranged valves. This gives optimal and fast filling and direct flushing via the inlet manifold followed by the combustion chamber (cross-flow) and the exhaust channel.
The squish surfaces together with the centrally positioned spark plug provide optimal combustion of the air/fuel mixture, low knock sensitivity and low, stable exhaust emissions.
The engine's oscillation-mounting consists of an engine bracket bolted in the cylinder head. The engine bracket meets a bracket which is secured in the side member. The other attaching point is located between the transmission and body. A third attaching point for absorbing reaction forces and rotational forces in the bearing bracket for the drive shaft.
The cylinder head is "chill" cast, a slightly slower procedure than die-casting. This is so to integrate exhaust, inlet channel, water and oil casing in the design.
The engine is approved according to emission requirements Euro 5. All bearings are lead-free. Screws are Chrome 6+ -free.
The bio-ethanol engine is a flex-fuel engine. The engine has a new cylinder head with valve seats on the inlet side and new fuel distribution pipe compared to the gasoline engine. These parts have harder surface coating to maintain service life as bio-ethanol (E85) has a corroding effect.
Valve play is slightly less and the fuel injection supply manifolds have more capacity than on a gasoline engine. The bio-ethanol engine has closer service intervals than a gasoline engine
The gasoline engine is powered by RON 95 fuel. The bio-ethanol engine is a flex-fuel engine and is powered by bio-ethanol (E85) or RON 95 fuel and all possible mixtures of these two fuels.
The bio-ethanol engine has a pre-mounted engine block heater that should be used to facilitate starts at low temperatures, In addition, the amount of gasoline in the fuel mixture should increase at temperatures lower than -10°C, to facilitate cold starts. Because bio-ethanol has a lower energy content than gasoline the engine uses up 40 % more bio-ethanol compared with gasoline.

Engine block




1. Cylinder head cover
2. Cylinder head
3. Cylinder block
4. Intermediate section
5. Oil pan
The engine block is divided into five parts, where the cylinder head consists of two parts (1 and 2) and the engine block of three parts (3, 4 and 5). The seal between the cylinder head and engine block is a conventional cylinder head gasket, while sealing between the other gasket surfaces is done with liquid gasket.

Cylinder head, camshaft bearing housing




The two camshafts are carried in six bearing races each directly in the cylinder head's two halves. The upper half functions as a combined valve cover and camshaft cap. It has cast oil distribution pipes on the underside which ensures good oil supply to the camshafts and the mechanical valve depressors. The lower half has the maintenance-free mechanical valve depressors, valve springs and valves.

Cylinder block




The engine block is divided into three sections, the cylinder block, intermediate section and oil pan. The mating flange between the cylinder block and intermediate section is in the center line of the crankshaft.
The cylinder block has five cast iron cylinder sleeves cast into the cylinder block which cannot be replaced. The six main bearing seats have cast iron reinforcements in the intermediate section.
On the top of the intermediate section there are cast oil channels which distribute the oil to the main bearings and on via the crankshaft to the big ends.
The oil pan contributes to the rigid construction and acts as additional reinforcement. There is central smooth-bore oil duct for piston cooling.

Oil pan




The oil sump is made of die-cast aluminum with baffles. This is so that the oil will not move too heavily. It is secured in the cylinder block and in between there is a liquid gasket LOCTITE, which ensures sealing between the cylinder block and oil sump. The oil suction line running from the sump is made of plastic. The oil sump is provided with an oil level sensor.

Crankshaft




The crankshaft has six main bearings. The 5th main bearing is a throw-out bearing. At the front end of the crankshaft are two spline joints, the inner of which drives the oil pump. The drive gear for the timing belt and vibration damper is on the outer joint.
Blind splines gives the right position and guides the drive gear. The connecting rods are forged and the cracked joint between the connecting rod and cap provides exact fixation of the caps. The forged crankshafts give maximal strength at the same time as they contribute to a low sound level.

Piston
The piston has a uniform aluminum alloy with graphite coating on the sides. This coating gives a certain friction reduction as well as noise damping. The piston rings are of different material depending on where they are mounted on the piston. The upper compression ring is a nitride steel ring. The lower compression ring is made of cast iron and the oil scraper ring is a design consisting of three parts, all made of nitride steel. The piston pin is made of hardened steel and is kept in place with steel lock rings. The form of the piston is oval and tapered with plane piston top. By reducing the top land area (distance between upper piston ring to piston top), the hydrocarbon emissions from the engine to the catalytic converter have been reduced.
The pistons are oil cooled so that they can have a lower compression height. Oil is led through a valve in a longitudinal channel in the lower section of the cylinder block on the exhaust side. There is a nozzle screwed to the channel at each cylinder. This leads the oil towards the underside of the piston.

Camshafts, Valve system




The camshafts are cast iron. The cam lobes which press against the valve lifters are hardened to tolerate the contact pressure. The valve lifters are steel and mechanical, not hydraulic.
There is a certain amount of valve clearance between the valve lifters and cam lobes. The valve clearance is adapted to compensate for differences in length between the valve and cylinder head due to expansion when warming up. Mechanical valve lifters ensure more precise valve timing, reduced friction, more stable combustion and reduced mass.
The material in the lifters is case-hardened steel. The surfaces between the camshaft and valve are slightly convex to guarantee centered contact.

Camshaft transmission




The timing belt that drives both camshafts and the coolant pump is a conventional single-tooth belt. The camshafts' belt pulleys are secured with three screws in each camshaft. The holes for the screws are oval to enable correct setting of the camshafts' position. Tensioning of the timing belt is obtained using a mechanical belt tensioner. The belt tensioner presses on the belt via a tensioner roller mounted on a lever. The idler roller on the belt's other side prevents the belt from starting to vibrate.

Mechanical belt tensioner




The tensioner consists or a spring and a friction element. The friction element provides the required damping to absorb small oscillations and speed variations. The spring ensures correct belt tension, irrespective of wear and temperature. The belts are made of cord reinforced rubber.

Auxiliaries belt




1. Alternator
2. Servo pump
3. Air conditioning (A/C) compressor
The auxiliary units consist of two belts and three auxiliary units. The auxiliary units (alternator, servo pump and AC compressor) are driven by two Poly-V drive belts. The main belt, which drives the servo pump and alternator, is tensioned by a mechanical belt tensioner mounted on the cylinder block. The belt that drives the AC compressor via a belt pulley on the servo pump is of "flexible" type and thus there is no belt tensioner.

Lubrication system




The oil is led from the oil pan via a suction piece to the oil pump. The oil pump is located on the cylinder block. The oil is then pumped onwards to the oil cooling system and then to the oil filter. The oil flows from the filter through a cast oil duct in the intermediate section to the main bearings. The oil then flows through drilled channels in the crankshaft to the connecting rod bearings.
The camshafts are supplied with oil by a bored channel in the cylinder block. The channel runs through the cylinder head, where it flows out at the bottom of the upper half of the cylinder head. There is a cross duct in the channel to the cylinder head which carries oil to the pistons via a piston cooling valve.
The oil flows on via an oil duct to the bearing for the left-hand camshaft and the valve lifters (intake side). The bearings for the right-hand side camshaft (exhaust side) are supplied by a cast cross duct at the front edge of the upper half. This cast cross duct also supplies pressurized oil to the solenoids for the VVT unit. Drain holes in the cylinder block release the oil from the cylinder head and crankshaft bearing back to the oil pan.

Oil filter




The oil filter holder is made of die cast aluminum. It is on the cold side of the engine. The oil filter cover is plastic. There is a by-pass valve in the cover. An O-ring in the cover ensures that it is sealed.

Piston cooling valve




The piston cooling valve is manufactured in steel with a hardened piston, a spring and a spring stop. A copper washer ensures that oil does not leak onto the cylinder block.

Intake system




The inlet system is divided into two parts, the upper and lower inlet manifold. The upper inlet manifold is made of plastic, and the lower inlet manifold is made of aluminum as this is to protect the fuel injectors in case of a collision.
The inlet system has short pipes and a total capacity of 3.0 liters.
The gasket between the lower inlet manifold and cylinder head is a double gasket with built-in non-return valve.

Throttle body
The throttle housing is die-cast in aluminum. The throttle disc is also made of aluminum. Under the plastic cover there are position sensors that read off the position of the throttle disc as well as two motor connections to the motor that turns the throttle disc, depending on the driver's requested throttle disc angle.
The throttle body (TB) does not need to be cooled, but may need to be heated. An O-ring in the intake manifold ensures the seal between the intake manifold and throttle body (TB).

Turbocharger (TC)




The integrated manifold and turbine housing are made of austenite forged steel to tolerate exhaust temperatures up to 1050 °C.
The bearing housing and turbine housing are held together by a V-shaped clamp. The compressor housing is made of die cast aluminum. The bearing housing is cooled by the oil and coolant system to prevent coking in the bearing for the turbine shaft which spins at up to 170,000 rpm.

Flame trap
The flame trap is made of die cast aluminum and integrated with the oil filter. The cyclone separators are plastic and cannot be replaced.

Cooling system




The coolant pump pumps coolant through the cylinder block, and also cools the cylinder head, cylinder sleeves, spark plug wells, intake ducts and fuel injection nozzles.
The coolant flows in at the pump and passes through a number of channels before it collects and then flows out to the thermostat housing. If the thermostat housing is closed, the coolant passes via the by-pass channel directly to the coolant pump to then circulate through the cylinder block again.
In principle, the oil cooler looks the same for the engine as for transmission. An inlet for oil with outlet, also for the coolant. The oil cooler is built in layers where water and oil flow around each other. Due to the very small spaces in the oil coolers, there is a great pressure-drop. When the fuel is combusted in the car's engine, both mechanical work and excess energy are produced. The excess heat is lead away from the engine in the exhausts, through convection to the air in the engine compartment and through transferring to the coolant as well as via the engine oil. The cooling is a closed system.

Oil cooler
The radiator is made of aluminum to tolerate the thermal variances when the radiator is being both cooled by cool air and heated by hot coolant.

Thermostat
The thermostat is in the thermostat housing which is in the connection to the coolant outlet from the cylinder head. At the heart of the thermostat is a wax body which expands with energy in the form of heat. In modern cooling systems, the thermostat begins to expand when the surrounding coolant temperature is 90 °C.