- The Y 25 DT engine, in comparison with the X 25 DT engine, is a DOHC engine.
- The two camshafts are located next to each other in the cylinder head.
- The outlet side camshaft on the right and the inlet side camshaft on the left.
- Two valves per cylinder are each actuated by one camshaft per side.
- The drive takes place via a chain which is tensioned automatically using a hydraulic tensioner via two tension rails.
- The drive chain is fitted around the drive gears of the two camshafts and the drive gear of the common rail high-pressure pump, which is driven by the crankshaft using its own drive chain, as in the X 25 DT engine.
- The camshafts are manufactured from a clear chill casting.
- The cams have a negative cam radius. By modifying the cam radius, the fuel consumption and the exhaust emissions have been reduced.
Illustration L0008384 shows the installation position of the camshafts.