Freelander System Description and Operation
ENGINE - K SERIES KV6
DESCRIPTION AND OPERATION 12-3-13
Description
General
The KV6 is of all aluminium construction, with a 90
°
V configuration. The KV6 uses long cylinder head bolts engaging
in threads 70 mm below the mating face of the cylinder block to attach the cylinder head to the cylinder block. This
ensures sufficient structural stiffness to take advantage of the compressive strength of aluminium alloy and minimise
tensile loadings. There are 8 cylinder head bolts for each cylinder head, located below the camshafts.
The engine features 24 valves, sequential fuel injection, liquid cooling and is transverse mounted. It is controlled by
a Siemens engine management system utilising a range of sensors to constantly monitor and optimise engine
performance.
ENGINE MANAGEMENT SYSTEM - SIEMENS, DESCRIPTION AND OPERATION, Description.
Cylinder Block Components
The cylinder block components are described below:
Cylinder Block and Main Bearing Ladder
The cylinder block is constructed of an aluminium alloy and is cast in three sections:
l
Cylinder block.
l
Main bearing ladder.
l
Lower crankcase extension.
For strength and rigidity, the main bearing ladder is manufactured from special alloy A357TF as used in manufacturing
components in the aerospace industry. The main bearing ladder is secured to the cylinder block with 16 bolts, thus
creating a very rigid crankcase 'box'. A separate outer crankcase extension adds further strength to the lower end of
the cylinder block. The lower crankcase extension is sealed to the underside of the cylinder block, using jointing
compound, and secured with 10 bolts. Fitted to the lower crankcase is an aluminium alloy sump.
Pistons and Cylinder Liners
The aluminium alloy, thermal expansion, lightweight pistons, with semi-floating gudgeon pins, are offset to the thrust
side and are carried on forged steel connecting rods. Pistons and cylinder liners are supplied in two grades, 'A' and
'B' and are also colour coded to assist identification. The pistons are marked to ensure they are correctly oriented in
the cylinder liner; the 'FRONT' mark should be toward the front of the engine.
The cylinder block is fitted with 'damp' cylinder liners, the bottom stepped half of the cylinder liner being a sliding fit
into the lower part of the cylinder block. The liners are sealed in the block with a bead of sealant applied around the
stepped portion of the cylinder liner. The top of the cylinder liner is sealed by a multi-layer steel cylinder head gasket
when the cylinder head is fitted.
The cylinder liner diameters are smaller than the big-end forging of the connecting rods and need to be removed
complete with pistons and connecting rods from the cylinder block.
Connecting Rods
The KV6 engine utilises forged steel H-sectioned connecting rods, with the gudgeon pin being an interference fit in
the small end of the connecting rod. The big-ends are horizontally split.
Big-end bearing diametric clearance is controlled by selective bearing shells with three grades of thickness. The big-
end upper and lower bearing shells are plain with locating tags.