PRODUCT INFORMATION INDEX DATE

Dep. 2
IT-C-V-15-002e October 2015

PISTONS VALIDATION CRITERIA

CONTENTS
1 INTRODUCTION ......................................................................................................................................... 3

2 OBJECTIVES ............................................................................................................................................... 3

3 VALIDATION METHOD ............................................................................................................................... 3

4 PERFORMANCE TESTS ............................................................................................................................ 5

4.1 PRE-TEST MEASUREMENTS ............................................................................................................................ 5

4.2 MINIMUM INSTRUMENTATION REQUIRED ...................................................................................................... 6

4.3 INSTALLATION .................................................................................................................................................... 6

4.4 PERFORMANCE TESTS ..................................................................................................................................... 7

4.4.1 PHASE 1: TEST OF MARKING, oil consumption and blow-by .................................................................... 7

4.4.2 PHASE 2: SEIZING RESISTANCE TEST .................................................................................................... 8

4.4.3 PHASE 3: MECHANICAL STRENGTH AND HEAT RESISTANCE ........................................................... 10

4.5 FINAL INSPECTION AFTER PERFORMANCE TEST ....................................................................................... 12

5 DURATION TESTS .................................................................................................................................... 13

5.1 PRE-TEST MEASUREMENTS .......................................................................................................................... 13

5.2 MINIMUM INSTRUMENTATION REQUIRED .................................................................................................... 13

5.3 ASSEMBLY ........................................................................................................................................................ 14

5.4 TEST .................................................................................................................................................................. 15

5.4.1 DURATION ................................................................................................................................................ 15

5.4.2 RECORDS ................................................................................................................................................. 15

5.4.3 INSPECTIONS ........................................................................................................................................... 15

TABLES
Table 1 Technical validation process ................................................................................................................ 4

Table 2 Minimum instrumentation required for the performance test ............................................................... 6

Table 3 Monitoring the marking and oil consumption test ................................................................................ 7

Table 4 Duration test data to be filled in ......................................................................................................... 15

Table 5 Revisions during the approval duration test....................................................................................... 15

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Table 6 Revisions during the duration test from technical validation to 10000 h ........................................... 16

FIGURES
Figure 1 Example of hot seizing test ................................................................................................................. 8

Figure 2 Templugs positions for a Ø 152 mm piston ........................................................................................ 9

Figure 3 Load cycle tests ................................................................................................................................ 11

Figure 4 Water temperature cycles test .......................................................................................................... 12

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PISTONS VALIDATION CRITERIA

1 INTRODUCTION
This document describes the tests to be made on the samples of pistons for their approval, for both existing
designs (due to a change of supplier) and for new designs.

This document gives the guidelines for validating the pistons, including performance tests on new pistons
and duration tests with oil consumption measurement.

There are therefore two types of approvals:

A. Designs already validated and now in production

Phases 1, 2 and 4 required (see Table 1: Phases description).
B. Tests of new designs.
Phases 1, 2, 3 and 4 required (see Table 1: Phases description).

2 OBJECTIVES
The objectives to be checked in the validation of rings are:

 Evaluation of seizing resistance.

 Evaluation of heat resistance.
 Evaluation of mechanical strength.
 Evaluation of piston/rings/sleeve compatibility.
 Blow-by admitted as per the IT-C-F-10-002 specification.
 Oil consumption as per the IT-C-F-10-002 specification.
 Evaluation of wear resistance: life according to the IT-C-F-10-002 specification.

3 VALIDATION METHOD
The first step in the technical validation tests is the performance tests in the tests cell to discount any type of
problem that may arise. The objectives of the performance tests are:

 Evaluation of seizing resistance.

 Evaluation of heat resistance.
 Evaluation of mechanical strength.
 Evaluation of compatibility with rings and piston.
A duration test lasting 2000 h is then carried out. As well as evaluating the pistons’ wear resistance, this test
is designed to discover the oil consumption and blow-by with the new piston to be validated.

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The complete technical validation process is shown below.

Table 1 Technical validation process

Main water
Load rpm Oil temp Oil level Duration Objective
temp
Piston profile, oil
PHAS Marking and oil
100% Nominal Nominal Nominal Nominal 100 h consumption and
E 1 consumption
blow-by

Minimum
Nominal/Max Nominal/ Minimu
100% Nominal 3.5 h installation
+ 10 ºC Max + 15º m
Hot seizing clearance
Piston and sleeve diameters that guarantee minimum clearance. The temperature must be
PHAS
increased in steps of 5 ºC for both oil and water, starting with nominal conditions and
E2
without exceeding the set limits. Each temperature state must last for 30 minutes.
Temperature in Piston operating
100% Nominal Nominal Nominal Nominal 2h
piston temperature

Sticking of rings
Overload 115% Nominal Max Max Nominal 100 h
and wear
Overspeed 100% 110% Nominal Nominal Nominal 200 h Hub resistance
PHAS Idle/ Resistance to
0/100% Nominal Nominal Nominal 200 h
E 3 Load cycles Nominal crown cracks
Load cycles variable from 0 to 100%
60/Max + 10 Resistance to
Heat cycles 0/100% Nominal Nominal Nominal 100 h
ºC seizing
Variable main water temperature cycles.

PHAS Wear
Duration 100% Nominal Nominal Nominal Nominal 2000* h
E4 Oil consumption
* The technical validation will end after 2000 h. However, the complete duration test must last for 10000 h, with
monitoring and intermediate and final inspections.

Diesel Gas
Nominal main water temperature 90 90/120
Maximum main water
temperature 96 96/126

Nominal oil temperature 90 95

Maximum oil temperature 100 105

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4 PERFORMANCE TESTS

4.1 PRE-TEST MEASUREMENTS

- Components
o Pistons
 Main diameters.
 Main heights.
 Roughness of skirt.
 Heights of ring grooves.
 Chamber volume.
 The manufacturer must provide reports on the measurements of the first
samples with at least:
 Main dimensional measurements.
 Inclination, straightness and undulation of the upper and lower surfaces
of the grooves.
 Perpendicularity of the grooves’ working surface with respect to the axis
of the piece.
 Lower half angle of the compression ring groove and its total angle.
 Piston crown profile from the top to the end of the skirt.
 Roundness of the skirt.

o Rings:
 Height.
 Width.
 Gap (free and when fitted in sleeve).
 Roughness of friction face.

o Sleeve
 Diameters: interior, exterior, flange.
 Heights of sleeve, slots, flange.
 Flatness of upper and lower flange faces.
 Surface finish of interior diameter.
 Coaxiality of the axes of the cylinders for fitting the sleeve in the block (upper
and lower gaskets areas) with respect to the piston’s internal sliding area.
 Perpendicularity of the axes of the cylinders for fitting the sleeve in the block
with respect to the inner face of the flange.

- Installation
o Minimum piston-cylinder head clearance. Measurement of the free height of the piston to
the cylinder head using leads.
o Clearance of the rings in their grooves. They must be free and meet the clearances in
their manufacturing drawings.
o Height of sleeve tab with respect to the block: check that it is correct.

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4.2 MINIMUM INSTRUMENTATION REQUIRED

The instrumentation for the engine used in the tests must collect at least the following measurements:

Table 2 Minimum instrumentation required for the performance test

Temperature Pressure Flow

Inlet air TA0_001 PA0_001 QA0_001
Compressor outlet air TA3_001 PA3_001
Intercooler outlet air TA4_005 PA4_005
Inlet manifold air TA4_001 PA4_001

Sump oil TO1_001

Main oil gallery PO5_001

Main engine water inlet TWP_001 PWP_001

Main engine water outlet TWP_301

Turbine inlet gases TA6_001 PA6_001

Turbine outlet gases TA8_001 PA8_001

Sump gases PO8_001 QO8_001

Fuel TC1_001 QC1_001

Speed
Power
Fuel consumption
Oil consumption
Emissions: NO, NO2, CO, CO2, O2, THC, CH4

4.3 INSTALLATION
The pistons to be validated must be installed with new standard sleeves. The test must start with clean oil
and new oil filters.

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4.4 PERFORMANCE TESTS

Before carrying out the approval tests themselves on the new pistons, a standard running-in must be
carried out, given that the moving parts are new. The standard running-in will depend on the engine in
which the pistons to be validated are installed and will be included in the relevant IP.

As mentioned above, the performance tests to be carried out are:

 Tests of designs validated and now in production: Phases 1 and 2 in the validation table, Table 1.
 Tests of new designs: Phases 1, 2 and 3 in the validation table, Table 1.

The following describes them in greater detail.

4.4.1 PHASE 1: TEST OF MARKING, OIL CONSUMPTION AND BLOW-BY

Main water
Load rpm Oil temp Oil level Duration Objective
temp
Piston profile, oil
PHAS Marking and oil
100% Nominal Nominal Nominal Nominal 100 h consumption and
E 1 consumption
blow-by

Recorder. See instrumentation in Table 2. Program alarm for blow-by.

PHASE 1: MARKING, OIL CONSUMPTION AND BLOW-BY

For monitoring the oil the following variables must be recorded daily (at the start and end of the daily test).

Table 3 Monitoring the marking and oil consumption test

Engine
Date Oil hours Tank level
hours

day h h (litres)

Inspection: After the test, remove three pistons in in-line engines and six pistons in V engines for
inspection. If everything is correct (evaluated by the supplier either in place or by sending it
photographs/necessary measurements) the components analysed must be returned to their same
positions.

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4.4.2 PHASE 2: SEIZING RESISTANCE TEST

Main water
Load rpm Oil temp Oil level Duration Objective
temp
Minimum
Nominal/Max Nominal/M Minimu
100% Nominal 3.5 h
installation
+ 10 ºC ax + 15º m
Hot seizing clearance
Piston and sleeve diameters that guarantee minimum clearance. The temperature must be
PHAS
increased in steps of 5 ºC for both oil and water, starting with nominal conditions and without
E2
exceeding the set limits. Each temperature state must last for 30 minutes.
Temperature in Piston operating
100% Nominal Nominal Nominal Nominal 2h
piston temperature

Recorder. See instrumentation in Table 2.

PHASE 2: HOT SEIZING

See the example test graph in Figure 1. The specific test graph must be prepared according to the nominal
and maximum temperatures for this specific engine.

Hot seizing test

Main ºC
Oil ºC

Limits
Temperature ºC

Time (min)

Figure 1 Example of hot seizing test

Inspection: After the test, remove three pistons in in-line engines and six pistons in V engines for inspection
(remove the same pistons as those after the tests in Phase 1 for see their development). If everything is
correct (evaluated by the supplier either in place or by sending it photographs/necessary measurements);
save these components. The components analysed must be returned to their same positions for the tests in
Phase 3.

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PHASE 2. TEMPERATURE IN PISTON

Install new pistons in the positions of those previously removed with templugs (specially-treated bolts
installed in the piece whose hardness depends on temperature) to obtain the piston’s map of maximum
operating temperatures. The pistons must have been fitted before hand by the manufacturer of the templugs.
The pistons must be fitted with the previously-removed rings, in the same positions.

See Appendix 1: Templug Data sheet.

See Appendix 2: Templug User Information Guide.

The following example shows the suggested measurement points for a Ø 152 mm piston.

Figure 2 Templugs positions for a Ø 152 mm piston

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Inspection: At the end of this test remove the instrumented pistons (three in in-line engines, six in V
engines) and send them for the maximum temperatures reached to be analysed.

For newly-designed pistons (Phase 3 necessary) re-install the components removed after the seizure test
in their same positions to start Phase 3.

If Phase 3 is not needed for the validation (existing design in production, new supplier), remove ALL the
pistons for final analysis after performance tests.

4.4.3 PHASE 3: MECHANICAL STRENGTH AND HEAT RESISTANCE

Main water
Load rpm Oil temp Oil level Duration Objective
temp
Sticking of rings
Overload 115% Nominal Max Max Nominal 100 h
and wear
Overspeed 100% 110% Nominal Nominal Nominal 200 h Hub resistance
PHAS Idle/ Resistance to
0/100% Nominal Nominal Nominal 200 h
E 3 Load cycles Nominal crown cracks
Load cycles variable from 0 to 100%
60/Max + 10 Resistance to
Heat cycles 0/100% Nominal Nominal Nominal 100 h
ºC seizing
Variable main water temperature cycles.

Recorder. See instrumentation in Table 2. Program blow-by alarm.

PHASE 3. OVERLOAD

Inspection: After the test, remove three pistons in in-line engines and six pistons in V engines for
inspection (remove the same pistons as those after the tests in Phases 1 and 2 to see the development).
If everything is correct (evaluated by the supplier either in place or by sending it photographs/necessary
measurements) the components analysed must be returned to their same positions for the next tests in
Phase 3.

PHASE 3. OVERSPEED

Inspection: After the test, remove three pistons in in-line engines and six pistons in V engines for
inspection (remove the same pistons as those after the tests in Phases 1 and 2 to see the development).
If everything is correct (evaluated by the supplier either in place or by sending it photographs/necessary
measurements) the components analysed must be returned to their same positions for the next tests in
Phase 3.

PHASE 3. LOAD CYCLES

See test graph in

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Figure 3.

Load cycle tests

Load

Load [%]

Time [s]

Figure 3 Load cycle tests

Inspection: After the test, remove three pistons in in-line engines and six pistons in V engines for
inspection (remove the same pistons as those after the tests in Phases 1 and 2 to see the development).
If everything is correct (evaluated by the supplier either in place or by sending it photographs/necessary
measurements) the components analysed must be returned to their same positions for the next tests in
Phase 3.

PHASE 3. HEAT CYCLES

See Figure 4 as an example of temperatures for engines, nominal 90 ºC, max 96 ºC. The specific
temperatures graph will depend on the engine.

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Water temperature cycles test

Main temperature ºC

Load [%]
Main ºC

Load

Time [min]

Figure 4 Water temperature cycles test

Inspection: After testing, remove ALL the pistons for final analysis by the supplier after performance
tests.

4.5 FINAL INSPECTION AFTER PERFORMANCE TEST

At the end of the performance test, remove ALL the pistons from each engine tested for sending to
the manufacturer for evaluation. The pistons and rings must be sent together with the sleeves and rings.

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5 DURATION TESTS
5.1 PRE-TEST MEASUREMENTS
The following measurements must be made.
- Components
o Pistons
 Main diameters
 Main heights
 Roughness of skirt
 Heights of ring grooves
 Chamber volume
 The manufacturer must provide reports on the measurements of the first
samples with at least:
 Main dimensional measurements
 Inclination, straightness and undulation of the upper and lower surfaces
of the grooves
 Perpendicularity of the grooves’ working surface with respect to the axis
of the piece
 Lower half angle of the compression ring groove and its total angle.
 Piston crown profile from the top to the end of the skirt
 Roundness of the skirt
o Rings
 Height
 Width
 Clearance (free and when fitted in sleeve)
 Roughness of friction face

o Sleeve
 Diameters: Interior, exterior, flange
 Heights of sleeve, slots, flange.
 Flatness of upper and lower flange faces.
 Surface finish of interior diameter.
 Coaxiality of the axes of the cylinders for fitting the sleeve in the block (upper
and lower gaskets areas) with respect to the piston’s internal sliding area.
Perpendicularity of the axes of the cylinders for fitting the sleeve in the block
with respect to the inner face of the flange

5.2 MINIMUM INSTRUMENTATION REQUIRED

The instrumentation for the engine used in the tests must collect at least the following
measurements.

 Oil consumption.
 Sump oil temperature.
 Sump pressure.
 Temperature in engine’s main circuit.
 Inlet manifold temperature.

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5.3 ASSEMBLY
It is recommended that the pistons duration tests be made in V engines because of the larger number of
units available for analysis afterwards.

The new rings must be installed with new sleeves and pistons.

The new pistons to be tested must be marked with:

X . YY
 
EngineNnumber
º motor N ºcilindro
Cylinder number

These pistons must be marked on the orientation hub at the bottom of the piston.

The pistons to be tested must be installed with new standard sleeves. The pistons se must be marked on
the bottom edge with:

X . YY
 
EngineNnumber
º motor N ºcilindro
Cylinder number

New rings must also be fitted.

The test must start with clean oil and new oil filters.

The following information must be recorded for sending to Guascor R&D for each engine:

 Plant and engine number.

 Engine model and serial number.
 Serial number of piston fitted in each cylinder.
 Installation date.
 Date engine started at start of test.
 Number of engine hours at start of test.

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5.4 TEST

5.4.1 DURATION
The minimum duration of the validation tests must be 2000 hours. If after 2000 h the pistons analysed are
OK, the technical validation is considered concluded. However, the duration test must continue with
suitable monitoring to complete 10000 hours.

5.4.2 RECORDS
The information recorded in the engine during the pistons tests (power, pressures and temperatures), and
the log of work to the engine (scheduled and unscheduled due to faults) and of alarms must also be sent
to Guascor R&D.

The monitoring of the oil consumption is primordial in this test, so it must be recorded every 50 hours
and sent periodically to Guascor R&D (every two weeks). The power generated by the engine must also
be noted (MWh). The temperatures of the oil, main water and inlet manifold must also be taken every 50
hours. The sump gases pressure must also be noted every 150 h.

The table with the data to be filled in for monitoring the oil consumption, the oil temperature and the sump
gases pressure is shown below.

Table 4 Duration test data to be filled in

Main Inlet
Sump
Engine Oil Tank Oil temp water manifold Sump oil
Week Date Power gases
hours hours level de carter temperat temperatur change?/Notes
pressure
ure e
1 day h h MWh (litres) ºC ºC ºC mm col

Report these data to Guascor every two weeks too.

The engine must have an alarm system to stop it because of high sump gases pressure.

5.4.3 INSPECTIONS

5.4.3.1 INSPECTIONS FOR VALIDATION

Two inspection mileposts are set for the technical validation, at 1000 h and 2000 h.

Table 5 Revisions during the approval duration test

For in-line engine: Remove one piston with its rings for inspection. Send the piston
to the supplier for analysis. Replace with new piston.
For in-line engine remove piston 1
1000 h
For V engine: Remove two pistons with their rings for inspection. Send the pistons to
the supplier for analysis. Replace with new pistons.
For V12 engine remove pistons 1 and 10.
For V16 engine remove pistons 1 and 12.
Remove two pistons with their rings for inspection in both in-line and V engines.
Send the pistons to the supplier for analysis. Replace with new pistons.
2000 h For in-line engine remove pistons 2 and 5
For V12 engine remove pistons 3 and 7
For V16 engine remove pistons 3 and 14

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5.4.3.2 INSPECTIONS FROM TECHNICAL VALIDATION TO 10000 H

Table 6 Revisions during the duration test from technical validation to 10000 h

Remove one piston with its rings for inspection (in both in-line and V engines). Send
the piston to the supplier for analysis. Replace with new piston.
4000 h
For in-line engine remove piston 3
For V engine remove piston 6
Remove one piston with its rings for inspection (in both in-line and V engines). Send
the piston to the supplier for analysis. Replace with new piston.
8000 h
For in-line engine remove piston 6
For V engine remove piston 11
Remove one (6L)/two pistons with their rings for inspection. Send the pistons to the
supplier for analysis. Replace with new pistons.
For in-line engine 6L remove piston 4 (the only remaining one with 10000 h)
10000 h
For in-line engine 8L remove pistons 4 and 8.
For V12 engine remove pistons 4 and 8.
For V16 engine remove pistons 7 and 9.

APPENDIX 1: Templug Data sheet

Vernolab_templug.pd
f

APPENDIX 2: Templug User Information Guide

TEMPLUGMAN.pdf

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