Specifications
ENGINE AND MANAGEMENT SYSTEM
The Group A engine specification has been fully
A correctly prepared and assembled unit should
developed in the International rallying arena
produce between 140 and 150 BHP, with
during 1989 and has shown to be powerful and
maximum power developed at between 6800
very reliable.
The special components required
and 7000
RPM.
t
o
build a replica power unit form the basis of
the Group A engine parts kit. Heavy duty engine
ENGINE PREPARATION PROCEDURE
mounting rubbers are included and fit as a direct
NOTE: IMPORTANT DETAILS
replacement for the standard components.
Before commencing the stripdown of the
Competition engine preparation is really a
standard engine unit and whilst the engine is in
very specialised operation and requires
running order, ensure that the ignition timing is
equipment and skills beyond the scope of a
correctly adjusted.
This should be 10 degrees
skilled vehicle mechanic. In spite of this, to
BTDC at idling speed.
Then mark the
assemble the Nova/Corsa 1600 engine and
distributor-to-cylinder head position so that this
Group A parts kit, would be a relatively easy
correctly timed position is not lost when the
task for most competent vehicle mechanics. The
distributor is removed.
Failure to do this will
basic engine design, the machined, cast and die
prevent correct repositioning of the distributor
cast finishes are to such a high standard on the
after the rebuild, and it would then require access
production unit that the need for excessive
to special electronic instrumentation to establish
i
ndividual component preparation is minimal.
the position.
By following the guidelines of this chapter, using
The big-end caps, whilst they are each
the special components supplied, correctly
matched to their conrod during machining, are
assembled would produce a fairly powerful and
NOT marked when fitted to the standard
reliable power unit.
The basic cylinder head is
production engine.
Before removal, mark the
very efficient in it's standard form, and the
big-end cap to conrod position to ensure rebuild
procedures outlined in this chapter do not extend
i
s
in correctly matchedorder.
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o
further
modification of the standard
component.
SUMP PAN
Obviously there is scope for optimisation of
power output by subtle modifications to both the
The standard sump pan is retained but requires
cylinder head, manifolds, and valve installation,
an additional baffle plate and pick-up pipe
although ALL dimensions must conform to those
protector to prevent oil surge during braking and
homologated. The nature of the possible
hard cornering manoeuvres. This specially
modifications is such that they should ONLY be
profiled baffle plate and the protector should be
carried out by a competition engine preparation
attached by `brazing' to the sump pan in the
specialist.
Cylinder head and manifold
positions shown in the diagram. It is important
modification, to realise a worthwhile gain in
not to exceed the maximum oil level marks on
power, requires knowhow combined with careful
the dipstick prior to subsequent competition use.
and laborious attention to detail.
Yet to throw
The oil surface could easily be picked-up by the
power away by an incorrect approach to the
rotating crankshaft, significantly increasing the
modifications is all too easy.
drag with a subsequent detrimental effect on
Please remember, that a good competition
power output.
engine can only be developed from a good
standard production unit. If at all possible
CRANKSHAFT
always use a new or very lightly used engine unit
If there is any doubt as to the type of use that the
as the basis for conversion to Group A
engine may have already had, measure the
specification.
Cleanliness and careful assembly is
crankshaft for wear and crack detect as a
the keynote to successful engine assembly.
precaution. Production balance levels are