Opel 1900 1973 Service Manual page 294

This engine has full skirt "Autothermic" type pistons
with two horizontal slots in oil control ring groove,
which partly separate head and skirt to maintain
good contact with the cylinder walls throughout the
entire temperature range.
The camshaft located in the cylinder head is an
important design feature of the new power units.
This arrangement permits an extremely rigid valve
train which accounts for precise valve timing. The
ing journals and cams. Installation of camshaft is
facilated by each diameter of the four bearings and
journals being slightly smaller than the preceding.
Camshaft end play is controlled at forward end by
ENGINE MECHANICAL AND MOUNTS
Figure 6A-1 Side Cross Section View of Engine
the camshaft front bearing seat outer face in one
direction, and by the front bearing cover in the other
direction. A nylon bolt in camshaft forward end
serves to adjust end clearance.
The camshaft is driven by an endless
chain. The crankshaft double sprocket and pulley
arc held by one key. The camshaft sprocket is fixed
with a guide pin and attached with 3 bolts.
Inside the timing case, a long damper block is prov-
ided on the driving side of the chain and a shorter,
curved spring plate tensioner on the non-driving
side. Both have wear-resistant and oil-proof sny-
tensioner located on driving side of chain at right
Duplex roller
chain