Engine Block

Fig 1: Engine (B8444S; 2005-2011)

Courtesy of VOLVO CARS CORPORATION

The cylinder heads and valve covers are made of aluminum.

The seal between the cylinder head and cylinder block occurs using two cylinder head gaskets, one for each cylinder head. The cylinder head gasket is made up of three layers of stainless steel. Two outer and a center which act as a seal around the cylinders. The outer surfaces of the gasket are covered by a rubber layer which functions as a seal. The seal between the other planes is made using liquid gasket.

Fig 2: Identifying Cylinder Bank Offset

Courtesy of VOLVO CARS CORPORATION

The engine has two cylinder banks. The left cylinder bank is slightly offset compared to the right. This allows the use of the vehicle's existing member system and crumple zones.

The engine has double pairs of overhead camshafts - one intake camshaft and one exhaust camshaft in each cylinder head. The camshafts are chain-driven.

Fig 3: Identifying Cylinder Number

Courtesy of VOLVO CARS CORPORATION

The cylinders are numbered in the order in which they are installed on the crankshaft when seen from the front (from the camshaft's timing gear).

Fig 4: View of Four Valves Per Cylinder

Courtesy of VOLVO CARS CORPORATION

The engine has four valves per cylinder. The valves are angled at 19 degrees. The valve diameter of the intake valves is 35 mm and the exhaust valve's is 30 mm. The valves are stellite coated. The valve stem diameter for both inlet and exhaust is 5.5 mm.

The combustion chamber is the "Pent roof" type. Together with the V arranged valves this gives optimal and fast filling and direct flushing via the intake channel followed by the combustion chamber (cross-flow) and 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.