Technical data

8
8
Cylinder head
The one-piece design of the cylinder head
offers advantages with regard to rigidity and a
reduction in sealing surfaces.
Both the idle air port as well as the secondary
air channel are integrated in the cylinder head.
Timing gear
A timing chain with separate chain tensioner
drives each intake camshaft (primary timing
gear). A toothed drive belt provides the drive
from the intake camshaft to the exhaust
camshaft (secondary timing gear).
For weight and friction reasons, the shape of
the hydraulic tappets in the S85 is based on
the box-type tappet as known from motor
racing engines. Since the tappets must not
rotate in the cylinder head, anti-torsion
needles which run in grooves milled into the
cylinder head are fitted in the tappets.
6 - Cross section of cylinder head (red = cut edge, orange = secondary air
channel, blue = water area, aqua = idle air port)
7 - Timing gear S85
8 - Valve train