Valves And Roller Finger Cam Followers
| Item | Description |
|---|---|
| 1 | Valve spring collet (quantity 48) |
| 2 | Roller finger cam follower (quantity 12) |
| 3 | Hydraulic valve tappet (quantity 12) |
| 4 | Valve spring retainer (quantity 24) |
| 5 | Exhaust valve spring (quantity 12) |
| 6 | Valve spring seat and valve stem seal (quantity 24) |
| 7 | Exhaust valve (quantity 12) |
| 8 | Intake valve (quantity 12) |
| 9 | Intake valve spring (quantity 12) |
The engine uses 24 valves:
- There are 12 intake valves
- There are 12 exhaust valves.
The intake valves are 30 mm (1.18 in) diameter and the exhaust valves are 28 mm (1.10 in) diameter. The larger the intake valve size, the more the engine can breathe. This gives more engine power output at higher Revolutions Per Minute (RPM).
The intake valve stems are 5.47 mm (0.22 in) and exhaust valve stems are 5.46 mm (0.21 in) 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 exhaust valves are opened mechanically by the roller finger cam followers, which operate directly with roller to camshaft lobe rolling contact. The clearance between the roller and camshaft lobe is compensated with the use of the hydraulic valve tappet. This makes sure that all roller finger cam followers are in contact with the camshaft lobes throughout engine operation.
The intake valves are opened by 2 Continuous Variable Valve Lift (CVVL) assemblies, controlled by the Powertrain Control Module (PCM).