ALUSIL®-Cylinder Blocks Porsche V6/V8 - KSPG AG

ALUSIL ® -Cylinder Blocks
Porsche V6/V8

1. ALUSIL ® Concept
KS Aluminium-Technologie GmbH has specialised almost exclusively
on aluminium cylinder blocks for the past ten years.
With KS/ALUSIL ® , the company is the market leader for cylinder
blocks made of the hypereutectic AlSi17Cu4Mg alloy.
ALUSIL ® cylinder blocks have gained wide acceptance in
spark-ignition engines for premier-class passenger cars with
a V block design, large swept volume and many cylinders.
The state-of-the-art casting process for the ALUSIL ® alloy is
low-pressure die casting. An ALUSIL ® cylinder block excels
through its monolithic character. Due to precipitation of primary
silicon which is finely distributed in the structure in
the form of small, very hard and thus wear-resistant crystals,
an additional reinforcement of the cylinder bores is not required
(see KS Aluminium-Technologie product information
“Low pressure die cast cylinder blocks”). KS Aluminium-
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Technologie has continuously optimized the ALUSIL ® concept
in connection with low-pressure die casting, and successively
raised the vertical range of manufacture, i.e. the
scope of machining in the foundry.
2. Pre-machining of low-pressure die cast cylinderblocks
Cylinder blocks produced in low-pressure die casting process
meet high quality standards. This is first of all ensured
by the low-turbulence die filling, typical of this casting process,
as well as the directional solidification. In addition, a
large number of quality tests are applied, such as leak tests
of the areas that come into contact with coolants and lubricating
oil, x-ray examination, crack tests as well as an ultrasonic
test of the bulkheads. In order to obtain a fast qual-
Fig. 1: ALUSIL ® -cylinder blocks from KS Aluminium-Technologie. Casting and finish machining from one single source illustrated by the
example of the Porsche V8 cylinder block for the “Cayenne” and „Panamera“

ity feedback, it has become common practise to perform
more or less comprehensive premachining processes at the
foundry. These processes serve to detect quality defects and
ensure that only those parts are delivered to the customer
that fulfil the requirements set out in the specification. Besides
tests of critical areas before supplying the parts, double
processing can be avoided by an intelligent definition of
the interface between the foundry and finishing processes at
the automobile manufacturer.
3. From pre-machining to finish machining –
a logical step
During the past few years, the interface between premachining
and finish machining has increasingly shifted towards
the foundry. In bulk production, however, the finish machining
processes for the cylinder block are still regarded as a
core competency of the vehicle manufacturers. Niche products,
by contrast, present a different picture. With production
volumes of up to 50.000 parts per year, outsourcing the
finish machining process for the cylinder block can mean a
considerable relief for the vehicle manufacturer. For foundries
with sufficient machining experience, this constitutes a
logical step forward and offers an interesting challenge to
in-crease the vertical range of manufacture.
4. Porsche V6/V8 project
For the development of the V6 and V8 engine for the “Panamera”
and for the “Cayenne”, Dr. Ing. h.c. F. Porsche AG
decided to have the cylinder block cast and finish machined
at one single place. KS Aluminium-Technologie was in the
vantage position to be able to refer to its successful series
delivery of the first V8 engine generation for the “Cayenne”
to bring to bear its competence as the market leader for cylinder
blocks from hypereutectic aluminium alloys (ALUSIL ® ).
Moreover, it could offer a convincing concept for the mixed
machining of V6/V8 including a new building at its Neckarsulm
location, with new, linked manufacturing centres as
well as the closeness of casting and machining facilities – an
especially attractive feature to persuade the customer. On
top of this was KS Aluminium-Technologie’s renewed assent
Fig. 2: Water jacket sand cores with distributor duct on the
outside and collector duct on the inside
Fig. 3: Ejection of the casting
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to take over the responsibility for honing the ALUSIL ® cylinder
bore surfaces. This involved the development to commercial
maturity of the process of mechanical uncovering of the
silicon crystals in a final honing step with an optimised cycle
time for ALUSIL ® . To this end, KS Aluminium-Technologie
was able to deploy its experience with the series production
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Top part of the cylinder block
� Core manufacture
� Casting
� Sawing off the ingate
� Milling the cylinder deck
� Core removal
� Heat treatment
Quality tests
1. Visual inspection
2. X-ray examination
3. Ultrasonic inspection of the
bulkheads
4. 3D dimension test
5. Crack detection
6. Hardness testing
Individual machining of the
top part
� Raw casting inspection
� Pre-machining
� Washing
� Cooling
� Leak test
Machining of assembled parts
� Bolting
� Cooling
� Assembly machining
� Washing
� Cooling
� Honing
� Washing, part identification,
demounting
� Mounting of small parts
Foundry/Preprocessing
� Casting
Finish machining
Bedplate
� Heat treatment
� Sawing off the ingate
� Cutting
Quality tests
1. Visual inspection
2. Hardness testing
3. Crack detection
4. X-ray examination
5. 3D dimension test
Individual machining of the
bedplate
� Raw casting inspection
� Pre-machining
� Washing
� Cooling
� Leak test
� Pinning
Quality tests
1. Visual inspections
2. SPC-Tests
3. Dimensional monitoring
„in process“
4. 3D dimensional test
5. Surface measurements
6. Cylinder form measurement
7. Evaluation of Si destruction
8. Residual dirt analyses
9. Final inspection
Fig. 4: Manufacturing process for the Porsche V6/V8 cylinder
block
of the first V8 engine generation. In addition, in connection
with Project 9A1 for the current generation of the opposedcylinder
engine of models 911 Boxster, Porsche and Cayman
likewise placed the order with KS Aluminium-Technologie as
single source provider embracing the full value chain.
4.1 Description of the cylinder block
Two-part design: top part (block) + bed plate
The cylinder block of the Porsche V6/V8 engine has a
two-part, extremely rigid structure consisting of the top
part and bed plate with a potential for further development.
The cylinder distance is 108 mm, the bore diameter
amounts to 96 mm. The interface is on a level with the
crankshaft centre line. The cylinder benches form the 90°
angle typical of V6/V8 engines. The top part of the cylinder
block has a closed-deck design and is made of the proven
ALUSIL ® alloy by low-pressure die casting. The block is stabilised,
meaning that a T5 heat treatment is employed. The
bedplate is also cast at KS Aluminium-Technologie from alloy
AlSi7Mg0.3 applying the low-pressure die casting method.
Before use, components from this temper-hardened alloy require
a “complete” T6 heat treatment, consisting of solution
annealing, quenching and subsequent artificial ageing.The
cylinder block is used both in the naturally aspirated and
turbo-charged engines.
Machining instead of coring for secondary-air and lubricating-oil
supplies as well as crank case ventilation
and/or pulsation pressure compensation
On the outside of each cylinder bench below the cylinder
deck, a secondary air duct is located. It is connected to the
cylinder head via bores in the cylinder deck. The secondary
air duct is not cored, but deep-hole drilled.
At the bottom of the V between the cylinder benches, the
main oil gallery is located. The oil jets for piston cooling arranged
at the crankcase side are directly connected to the
main oil gallery. The main oil gallery is supplied by a pressure
oil duct that runs upwards diagonally from the interface

on the front side. The unpressurised oil drain ducts are arranged
on the outside side walls of the top part of the cylinder
block.
On both sides of the main oil gallery, there are ducts that
are connected with the crankcase on the one hand and, via
risers on the V insides, with the cylinder deck on the other.
This duct system serves for ventilation, i.e. the extraction of
blow-by gases into the cylinder head, where they are recycled
on the inlet side after passing through an oil separator.
The main oil gallery and the blow-by longitudinal ducts are
not cored, but deep-hole drilled. In other cases, too, drilling
is preferred to coring for low-pressure die-cast parts, if practicable.
The oil drain ducts, for example, are cored on the
upper side, but drilled from below. Each of the bulkheads
has two openings (windows) to equalise pressure pulsation.
These are deep-hole drilled from one side and capped on
the gearbox side.
Key development projects
Development efforts focused on the efficient use of the available
material potential while at the same time preserving a
rigid baseline design. Compared to the forerunner generation
of the V8 engine, a total weight reduction by 13.5 kg
was achieved thanks to the design innovation geared to the
selective reduction of the wall thicknesses, the elimination
of the grey cast inlays and the integrated oil separator wall in
the bedplate. So, among other benefits, the higher thermal
expansion of aluminium can be partly compensated for to
control the main bearing play. The area of the main bearings
is provided with a double screw connection (four main bearing
screws per bulkhead). The distinctly improved equalization
in cylinder pressure distribution thus achieved enabled
the screw stress to be lowered and as a result cylinder distortions
were reduced by up to 28 % compared to the previous
engine generation.
Fig. 5: CNC-machining center with interconnection Fig. 6: Automized transfer of bedplates
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4.2 Manufacturing concept for the cylinder block
4.2.1 Casting
The top and bottom parts of the cylinder block are cast in
the recently erected foundry building in state-of-the-art
low-pressure casting bays (Figures 2 and 3). Gating is performed
at the centre below the bulkheads. The steel dies are
equipped with a well thought-out cooling system in the cylinder
bore steel core and “bottom tower steel core” area (the
“bottom tower cores” form the crankcase). The casting process
is completely monitored and documented by means of
the socalled “Intellution” system. Downstream of the casting
process, the decoring, sawing and milling operations as
well as quality checks are performed.
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4.2.2 Finish machining of individual parts
The cylinder block is finish machined on newly installed
equipment. To this end, an existing building was restructured
and extended. The foundry and machining equipment
are located within immediate vicinity. The manufacturing
concept for the ALUSIL ® cylinder block is shown in Fig. 4. In
addition, Figures 5 to 10 provide an impression of individual
manufacturing stations and operations performed at these
places.
Fig. 7: Automized transfer of machined cylinder blocks Fig. 8: Married and screwed components

The manufacturing sequence is composed of the following
main processes:
Parallel machining of the cylinder block upper part and
bed plate, cleaning, storing/cooling and leak test
Marriage of the two individual parts, assembly processing,
honing including mechanical uncovering of silicon
crystals
Between different operations: cleaning and/or storing/
cooling
As a final step, cleaning, high-pressure cleaning and deburring,
assembly of small parts and quality checks.
5. Summary and conclusion
With the supply of finish machined and honed ALUSIL ® cylinder
blocks for the V8 engine of the Porsche “Cayenne” and
“Panamera” KS Aluminium-Technologie is furnishing proof
of its extended competence and capability in this field. The
project points the way to the future for niche products with
small to medium production outputs.
Fig. 9: Honing facility (cylinder bores and crankshaft bearing bores) Fig. 10: Dimensional test with 3D coordinate measuring machine
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KS Aluminium-Technologie GmbH · Hafenstraße 25 · 74172 Neckarsulm · GERMANY
Tel. +49 7132 33-1 · Fax +49 7132 33-4357 · www.kspg.com
Subject to alterations. Printed in Germany. A|IX|k