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Prepare to and machine engine cylinder heads
Level
4
Credits
20
Purpose
This unit standard is for people in the automotive machining industry. People
credited with this unit standard are able to prepare to machine engine
cylinder heads, and machine engine cylinder heads.
Subfield
Motor Industry
Domain
Engines
Status
Registered
Status date
25 January 2008
Date version published
25 January 2008
Planned review date
31 December 2012
Entry information
Open.
Accreditation
Evaluation of documentation and visit by NZQA and
industry.
Standard setting body (SSB)
NZ Motor Industry Training Organisation (Incorporated)
Accreditation and Moderation Action Plan (AMAP) reference
0014
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Special notes
1
Legislation relevant to this unit standard includes but is not limited to – Health and
Safety in Employment Act 1992; Resource Management Act 1991, s15 Discharge of
contaminants into environment.
2
Definitions
Company requirements refer to instructions to staff on policy and procedures which
are documented in memo or manual format and are available in the workplace.
These requirements include but are not limited to – company specifications and
procedures, work instructions, manufacturer specifications, product quality
specifications, and legislative requirements.
Machining refers to the complete rebuild of the cylinder head assembly which
includes the machining operations as stated in this unit standard, and the use of new
or re-machined components as required to make the head assembly fully and safely
operational.
 New Zealand Qualifications Authority 2016
11727 version 3
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Suitable tools and equipment means industry approved tools and equipment that are
recognised within the industry as being the most suited to complete the task in a
professional and competent manner with due regard to safe working practices.
3
Assessment against this standard includes cast iron and aluminium alloy cylinder
heads from both petrol and diesel multi-cylinder engines. Two different valve
configurations are required to be assessed.
Elements and performance criteria
Element 1
Prepare to machine engine cylinder heads.
Performance criteria
1.1
Safe working practices are observed throughout the task in accordance with
legislative requirements.
Range
personal safety, safety of others, workshop safety, environmental
safety, tools and equipment safety.
1.2
Suitable tools and equipment are selected and used to enable the condition of
the engine cylinder head to be prepared for machining in accordance with
company requirements.
1.3
Engine cylinder heads are cleaned and decarbonised without damage to
components, in an environmentally safe manner, and in accordance with
company requirements.
Range
chemical cleaning bath, scraping, buffing, media blasting.
1.4
Engine cylinder heads are hardness tested in accordance with engine
manufacturer specifications.
1.5
Engine cylinder heads are crack tested and pressure tested in accordance with
company requirements.
Range
crack test includes one of – dye penetrant test, magnetic particle
test.
Element 2
Machine engine cylinder heads.
Performance criteria
2.1
Safe working practices are observed throughout the task in accordance with
legislative requirements.
Range
personal safety, safety of others, workshop safety, environmental
safety, tools and equipment safety.
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2.2
Suitable tools and equipment are selected and used to enable the engine
cylinder head to be machined in accordance with company requirements.
2.3
Crack repairs are completed so that the engine cylinder head is restored to
normal operating condition in accordance with company requirements.
Range
2.4
welding, stitching, plugging.
Corrosion repairs are completed so that the engine cylinder head is restored to
normal operating condition in accordance with company requirements.
Range
welding, grinding, machining.
2.5
Valve guides are removed and replaced in accordance with company
requirements.
2.6
Valve guide inserts are machined and fitted in accordance with company
requirements.
2.7
Valves and valve seats are checked to ensure contact and surface finishes are
within the manufacturer specifications, and any remedial work is carried out in
accordance with company requirements.
Range
may include but is not limited to – refacing seats, lapping seats,
replacement.
2.8
Valve seat inserts are replaced in accordance with manufacturer specifications.
2.9
Valve seat recesses are machined to enable an insert to be fitted in accordance
with company requirements.
2.10
Valve on-seat spring heights are checked and set to the engine manufacturer
specifications.
2.11
Pre-combustion chambers (where fitted) are removed and replaced in
accordance with company requirements.
2.12
Rocker assemblies are repaired in accordance with company requirements.
Range
2.13
All head faces are machined to comply with engine manufacturer specifications.
Range
2.14
replacement of parts, rebushing, refacing arms.
surface grinding, milling.
Broken studs are removed and threads are restored to enable new studs to be
torqued to engine manufacturer specifications.
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2.15
Engine cylinder head internal and external threads are restored to engine
manufacturer specifications or thread insert manufacturer instructions.
Range
tapping, using dies and die nuts, recoiling.
2.16
Frost plugs are replaced and sealed to prevent the escape of coolant under
engine operating conditions.
2.17
All coolant and oil passages are cleared to enable normal circulation to occur.
2.18
Where required, an aluminium alloy cylinder head is straightened to within the
engine manufacturer specifications, and align bored in accordance with engine
manufacturer specifications.
2.19
Overhead camshaft bearings are fitted and sized in accordance with company
requirements.
2.20
Engine cylinder head injector tubes (if fitted) are removed and replaced in
accordance with company requirements.
2.21
Cast iron manifolds are prepared, welded, and machine finished in accordance
with manufacturer specifications.
2.22
Engine cylinder head is vacuum tested to ensure valves are seated in
accordance with equipment manufacturer specifications.
2.23
The machined engine cylinder head is lubricated, protected against damage
and foreign matter, and labelled to ensure identification in accordance with
company requirements.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP also includes useful information about special requirements for organisations
wishing to develop education and training programmes, such as minimum qualifications for
tutors and assessors, and special resource requirements.
Comments on this unit standard
Please contact the NZ Motor Industry Training Organisation (Incorporated)
info@mito.org.nz if you wish to suggest changes to the content of this unit standard.
 New Zealand Qualifications Authority 2016