PRODUCT INFORMATION
INDEX
DATE
Dep. 2
IC-G-D-00-040e F
May 2016
GAS ENGINES GENERAL DESCRIPTION OF CONSTRUCTION
3/4
2.9. CAMSHAFT
The camshafts (one for in-line and two in V-engines) are made from alloy steel and induction tempered or case
hardened (HGM and SFGM).
The cams have been calculated to optimise the operation of all the engine distribution; camshaft drive is through
gear arrangement.
The cam followers are of the roller type, mounted on a rocker arm.
2.10. DISTRIBUTION
Timing gears, i.e. the drive system of such components as camshafts, regulators, oil pump and water, consist of
spur gears on in-line engines and helical gears on V-engines.
2.11. LUBRICATION
The oil pump is a gear pump type, driven by means of gears from the crankshaft. The lubrication system also
consists of interchangeable filters, thermostatic oil temperature regulation (V-engines), oil refrigeration,
regulation of the lubrication oil pressure, in addition to safety systems like centrifugal filters according to the
application concerned.
2.12. REFRIGERATION
There is two types of refrigeration:
-
The engine is cooled by a double water circuit. A main circuit which cools the motor crankcase, cylinder
heads and exhaust manifold (except in the case of dry exhaust manifold) as well as the air-fuel mixture on
engines with double-stage intercooler, and an auxiliary circuit for cooling the oil and the air-fuel mixture.
There are some configurations in which the oil cooler is cooled by the main circuit in parallel with the other
parts of the engine.
-
The engine is cooled by just one water circuit. In line engines the oilcooler and the mixture cooler are in
series, and both in parallel to the block, cylinder-heads and exhaust manifold. In v engines oilcooler and
mixture cooler are in parallel and both are in parallel to the block, cylinder-heads and exhaust manifold.
the mixture cooler is one stage intercooler.
Cooling circuits can include pumps that can be driven by gears from the crankshaft.
2.13. CARBURETION
The gas system consists of an air/fuel ratio adjustment system (mechanical, screw-type on
FG/FGLD/SFGLD/SFGM-series engines and electronic on SFGRD/SFGLD/SFGM and HGM series engines and
a Venturi type carburettor.
Following the specifications and general standards, a valve train is always installed before the engine to
guarantee the safety of the gas installation.
2.1.13
O&M_2.002211.810_A_10_2016
