Camshaft Carrier
| ITEM | DESCRIPTION |
|---|---|
| 1 | Fuel rail |
| 2 | Fuel injector (4 off) |
| 3 | Oil filler and cap assembly |
| 4 | Engine breather |
| 5 | Engine vent module |
| 6 | Camshaft carrier |
| 7 | Exhaust camshaft and Variable Camshaft Timing (VCT) actuator |
| 8 | Intake camshaft |
| 9 | Camshaft cap (9 off) |
| 10 | Bolt - Camshaft cap (20 off) |
The structural camshaft carrier is cast from aluminum alloy using a high pressure die cast process. The camshaft carrier is located on two dowels in the cylinder head and secured with bolts. A single layer steel gasket with cured in place sealant seals the camshaft carrier to the cylinder head.
The primary function of the camshaft carrier is to house and secure the intake and exhaust camshafts. The camshaft bore geometry is bored in a single machining operation to ensure optimum friction reduction and each camshaft cap is uniquely identified and must be matched to its related bore.
The camshaft carrier also provides locations for the Camshaft Position (CMP) sensor, the oil filler pipe and the engine vent module. The camshaft carrier has high pressure oil galleries feeding the Variable Camshaft Timing (VCT) actuator and provides thrust face lubrication. A low pressure oil gallery returns oil from the engine vent module back to the cylinder block and oil pan.
The camshaft carrier also provides the locations for the fuel rail, engine breather and the oil filler cap.
VALVES AND ROLLER FINGER CAM FOLLOWERS
| ITEM | DESCRIPTION |
|---|---|
| 1 | Hydraulic valve tappet (16 off) |
| 2 | Roller finger cam follower (16 off) |
| 3 | Valve spring collets (32 off) |
| 4 | Valve spring retainer (16 off) |
| 5 | Valve spring (16 off) |
| 6 | Valve spring seat (16 off) |
| 7 | Valves - 8 off intake, 8 off exhaust |
The engine uses sixteen chrome plated steel valves, eight intake and eight exhaust. The intake valves are 27.3mm diameter and the exhaust valves are 25.7mm diameter. The larger intake valve size will enhance more engine power output at higher Revolutions Per Minute (RPM). The intake valve stems are 5.47 mm diameter and exhaust valve stems are 5.463mm diameter. These allow reduced flow interruption through the intake and exhaust ports, improving performance and emissions.
The valves are located in conventional, non serviceable valve guides in the cylinder head. A valve stem seal with integral spring seat is located in the cylinder head. The valve spring is retained in a compressed state on the valve stem by a valve spring retainer and a pair of valve spring collets. The valves are opened mechanically by a roller finger cam follower design which is operated directly with roller to camshaft lobe rolling contact. The clearance between the roller and camshaft lobe is compensated with the use of a hydraulic valve tappet. This ensures that all roller finger cam followers are in contact with the camshaft lobes throughout engine operation.
The valves are located in conventional, non serviceable valve guides in the cylinder head. A valve stem seal with integral spring seat is located in the cylinder head. The valve spring is retained in a compressed state on the valve stem by a valve spring retainer and a pair of valve spring collets. The valves are opened mechanically by a roller finger cam follower design which is operated directly with roller to camshaft lobe rolling contact. The clearance between the roller and camshaft lobe is compensated with the use of a hydraulic valve tappet. This ensures that all roller finger cam followers are in contact with the camshaft lobes throughout engine operation.