CYLINDER HEAD EXHAUST FACE SALVAGE BY

WELDING PROCESS AT CUMMINS PVT. LTD.,

PITHAMPUR
A Project Work - II Report
Submitted in partial fulfillment of requirement of the
Degree of
BACHELOR OF TECHNOLOGY in
MECHANICAL ENGINEERING
BY
Md Fardeen Qureshi
EN16ME303078
Rana Rajwardhan Singh
EN16ME303109

Under the Guidance of

Mr. Amit Prajapati Mr. Jawed Ali
Assistant Professor Plant - Leader
Mechanical Department Product Engineering Department
Medi-Caps University Cummins Technologies India Pvt. Ltd.

Department of Mechanical Engineering

Faculty of Engineering
MEDI-CAPS UNIVERSITY, INDORE- 453331
JUNE 2020
CYLINDER HEAD EXHAUST FACE SALVAGE BY
WELDING PROCESS AT CUMMINS PVT. LTD.
PITHAMPUR
A Project Work - II Report
Submitted in partial fulfillment of requirement of the
Degree of
BACHELOR OF TECHNOLOGY in
MECHANICAL ENGINEERING
BY
Md Fardeen Qureshi
EN16ME303078
Rana Rajwardhan Singh
EN16ME303109

Under the Guidance of

Mr. Amit Prajapati Mr. Jawed Ali
Assistant Professor Plant - Leader
Mechanical Department Product Engineering Department
Medi-Caps University Cummins Technologies India Pvt. Ltd.

Department of Mechanical Engineering

Faculty of Engineering
MEDI-CAPS UNIVERSITY, INDORE- 453331
JUNE 2020
 Report Approval

The project work “Cylinder Head Exhaust Face Salvage By Welding Process”
is hereby approved as a creditable study of Mechanical engineering subject
carried out and presented in a manner satisfactory to warrant its acceptance as
prerequisite for the Degree for which it has been submitted.

It is to be understood that by this approval the undersigned do not endorse or

approved any statement made, opinion expressed, or conclusion drawn there in;
but approve the “Project Report” only for the purpose for which it has been
submitted.

Internal Examiner
Name:
Designation
Affiliation

External Examiner
Name:
Designation
Affiliation

ii
 Declaration

We hereby declare that the project entitled submitted in partial fulfillment for the
award of the degree of Bachelor of Technology in Mechanical Engineering
completed under the supervision of Mr. Amit Prajapati, Assistant Professor,
Mechanical Department, Faculty of Engineering, Medi-Caps University Indore
and Mr. Jawed Ali, Plant Leader, Cummins Turbo Technologies Pvt. Ltd. is an
authentic work.

Further, we declare that the content of this Project work, in full or in parts, have
neither been taken from any other source nor have been submitted to any other
Institute or University for the award of any degree or diploma.

Md Fardeen Qureshi
EN16ME303078

Rana Rajwardhan Singh

EN16ME303109

iii
 Certificate

We, Prof. Amit Prajapati and Mr. Jawed Ali certify that the project entitled
“Cylinder Head Exhaust Face Salvage By Welding Process” submitted in
partial fulfillment for the award of the degree of Bachelor of Technology by
Md Fardeen Qureshi and Rana Rajwardhan Singh is there carried out by them
under our guidance and that the work has not formed the basis of award of any
other degree elsewhere.

________________________________ ________________________________

Prof. Amit Prajapati Mr. Jawed Ali

Mechanical Department Plant Leader Product Engg.

Medi-Caps University, Indore Cummins tech. Pvt. Ltd.

_____________________

Prof. Mohammed Ali

Head of the Department

Mechanical Department

Medi-Caps University, Indore

iv
 Acknowledgements

We would like to express my deepest gratitude to Honorable Chancellor,

Shri R C Mittal, who has provided me with every facility to successfully carry
out this project, and my profound indebtedness to Prof. (Dr.) Sunil K Somani,
Vice Chancellor, Medi-Caps University, whose unfailing support and enthusiasm
has always boosted up my morale. We also thank Prof. (Dr.) D K Panda, Dean,
Faculty of Engineering, Medi-Caps University, for giving me a chance to work
on this project. We would also like to thank my Head of the Department
Prof. (Dr.) Mohammed Ali for his continuous encouragement for betterment of
the project.

We express my heartfelt gratitude to my External Guide, Mr. Jawed Ali, Plant

Leader, Cummins Tech. Pvt. Ltd. as well as to my Internal Guide,
Prof. Amit Prajapati, Assistance Professor, Medi-Caps University, without
whose continuous help and support, this project would ever have reached to the
completion.

We would also like to thank to my team at Cummins, Mr. Ashfaq Ali, Mrs. Preeti
and Mr. Vikas who extended their kind support and help towards the completion
of this project. It is their help and support, due to which we became able to
complete the design and technical report.

Without their support this report would not have been possible.

Md Fardeen Qureshi
Rana Rajwardhan Singh
B.Tech. IV Year
Department of Mechanical Engineering
Faculty of Engineering
Medi-Caps University, Indore

vii
 Abstract

The Cylinder Head is not only a very important part of your engine, but also one of the most
expensive parts of the vehicle's engine due to its complex structure. The main task of the
cylinder head is to close the combustion chamber of the engine from the top. The upper part of
the engine is called the cylinder head, while the lower part is the engine block. Unfortunately,
the complex structure of the cylinder head and its numerous tasks make it prone to defects. The
most common defect is a leaking cylinder head gasket, which is caused by an increased
abrasion.

A method for weld repair for heavily damage cylinder head exhausts face. The cylinder heads
were rejected even after being fully salvaged all the possible defects due to this damage. The
damage contain heavy pitting marks on the exhaust face gasket non contacting area, which is
termed as Zone-1( localized near exhaust port) and Sealing marks or Impression observed in
gasket sealing area, which is termed as Zone-2 (widespread over the exhaust face). The method
involves Grinding, Welding and carefully controlled Preheating.

Keywords: Salvage, Zone.

viii
 Table of Contents
Page No.

Report Approval ii
Declaration iii
Certificate iv
Acknowledgement v
Abstract vi
Table of Contents vii
List of figures viii

Chapter 1 Introduction 1
1.1 Cummins Overview 1
1.2 Business Units 2
1.3 History 3
1.4 Plants in India 3
1.5 Cummins Pithampur 4
1.6 Recon 5-7
1.7 Cummins Recon Products 7-11

Chapter 2 Project Analysis 12

2.1 Literature Review 12-15
2.2 Problem Statements 15-21
2.3 Objective 21

Chapter 3 Proposed Methodology 22

3.1 Process Flow 22-23
3.2 Steps Involved 23-25
3.3 Welding of Cast Iron 25-30
3.4 Shielded Metal Arc Welding 30-33
3.5 Finishing 33

Chapter 4 Result and Discussion 34

4.1 Limitation of the Salvage 34
4.2 Conclusion 34

Chapter 5 Future Scope 35

References 36

ix
 List of Figures
Page No.

Fig. 1.1 Cummins Logo 1

Fig. 1.2 A Cummins’ Product 2

Fig 1.3 Cummins’ location in India 4

Fig. 1.4 Cummins departments in Pithampur 4

Fig. 1.5 Core – Cylinder Head 5

Fig. 1.6 Recon Organisations Structure 6

Fig. 1.7 Turbocharger 8

Fig. 1.8 Lube Oil Pump 8

Fig. 1.9 Water Pump 9

Fig. 1.10 Cam and Follower 11

Fig. 1.11 Cylinder Head 12

Fig.2.1 Defective Cylinder Head 15

Fig.2.2 Cylinder Head Line Process Flow Chart 17-19

Fig.2.3 Pitting Marks 20

Fig.2.4 Damage observed at the wall 20

Fig 2.5 Exhaust Face Defect Type 21

Fig.3.1 Process Flow Chart for Zone 1 22

Fig.3.2 Process Flow Chart for Zone 2 23

Fig.3.3 Grinding and Welding Area 24

Fig.3.4 Grinding Process 24

Fig.3.5 Welding Process 25

Fig.3.6 Shielded Metal Arc Welding 30

Fig.3.7 Welding Operation 31

Fig.3.8 Cylinder Head - Just after Welding 33

Fig.3.9 Finishing 33

x
 Chapter-1
Introduction

1.1 Cummins’ Overview

Cummins Turbo Technologies (CTT) , a global power leader, is a corporation of

complementary business units that design, manufacture, distribute and service engines and
related technologies, including fuel systems, controls, air handling, filtration, emission
solutions and electrical power generation systems.
It is an American corporation that designs, manufactures, and distributes engines, filtration,
and power generation products. Cummins also services engines and related equipment,
including fuel systems, controls, air handling, filtration, emission control, electrical power
generation systems, and trucks.
Headquartered in Columbus, Indiana, United States, Cummins sells in approximately 190
countries and territories through a network of more than 600 company-owned and
independent distributors and approximately 6,000 dealers. [8]

Fig. 1.1 Cummins Logo

Cummins reported net income of $2.19 billion on sales of $23.77 billion in 2019.

VISION : Making people’s lives better by unleashing the Power of Cummins.

Cummins Headquaters is situated in Columbus, Indonesia. It was founded in 1919. In 2019,

Cummins earned $1.85 billion. Its fortune Rankings in 2019 was 125 out of 500. It has over
44000 employees worldwide. Its customers are located in approximately 190 countries.

1
1.2 Business Units
Cummins is organized into four business units:

1.2.1 Cummins engine business

The Engine Business manufactures and markets a complete line of diesel and natural gas-
powered engines for on-highway and off-highway use. Markets include heavy- and medium-
duty trucks, buses, light-duty trucks and industrial uses such as agricultural, construction,
mining, marine, oil and gas and military equipment.

1.2.2 Cummins power generation business

Power Gen is a global provider of power generation systems, components and services in
standby power, distributed power generation, as well as auxiliary power in mobile
applications. It also provides a full range of services including long-term operation and
maintenance contracts and turnkey and temporary power solutions.

1.2.3 Components business

Cummins Emission Solutions designs and manufactures exhaust after treatment technology
and solutions for the medium and heavy-duty, and high-horsepower engine markets.

Cummins Filtration designs and builds heavy-duty air, fuel, hydraulic and lube filtration,
chemicals and exhaust system technology products.[8]

Fig. 1.2 A Cummins’ Engine

Cummins Fuel Systems designs and manufactures new fuel systems and rebuilds Electronic
Control Modules.

2
Cummins Turbo Technologies designs and builds turbochargers to boost engine power and
related products.

1.2.4 Cummins distribution business

Seventeen Company-owned distributors and 10 joint ventures work through 233 locations
worldwide – selling and distributing Cummins-branded products and services.

1.3 History

The values of integrity, innovation and corporate responsibility have deep roots at Cummins,
going back to the Company’s founding in 1919. Three men helped shape the Company in
each of these areas. Their influence is still felt today.

1.4 Plants in India

Cummins began its India operations on 17 February 1962 in a joint venture with the Kirloskar
Group. The ownership structure of the joint venture was divided as follows:

Cummins - 50%

Kirloskar Group - 25.5%

Retail Investors - 24.5%

In 1996 Cummins Inc. bought Kirloskar shares. Now its Cummins Inc. subsidiary. As of
2013, the Cummins group had revenues of over $1.5 billion, 20 factories and 9000 employees
in India.

Cummins does a significant part of its R&D in India at the Cummins Research and
Technology centre that was set up in 2003. Also, Cummins is building an advanced technical
centre in Pune which will house over 2000 engineers.

Cummins India has also made significant contributions to local skill development by
establishing the MKSSS's Cummins College of Engineering for Women, a women-only
engineering college in Pune.[8]

3
 Fig. 1.3 Cummins’ Location in India

1.5 Cummins Pithampur

Established in 2015 , Cummins Turbo Technologies Ltd. has made a name for itself in the list
of top suppliers of in India. The supplier company is located in Pithampur, Madhya Pradesh
and is one of the leading sellers of listed products. The Pithampur plant is Located at Sector
3, SEZ, Pithampur, Dist – Indore, (M.P).

Cummins Turbo Technologies Ltd. is listed in Trade India's list of verified sellers offering
supreme quality of etc. Buy in bulk from us for the best quality products and service.
In this plant, there are two departments :

CUMMINS
PITHAMPUR

CTT RECON
(Cummins Turbo (Recontruction)
Tech.)

Fig. 1.4 Cummins’ Departments in Pithampur

4
CTT deals with New product Manufacturing, while RECON deals with Salvaging (Repairing
of old Parts/ Core). In India, Cummins import the Core from abroad, Works on it and send
back to the abroad. There no business of Cummins in India.

Fig. 1.5 Core – Cylinder Head

1.6 Recon

It is the remanufacturing plant where the different automobile components are dismantled and
various salvaging process are implemented. RECON deals with the Core, i.e., the used
component . RECON recycle or repair core by using different Salvage techniques.

CUMMINS imports and exports only with countries like UK, Russia. There is no market
share in INDIA.

RECON is a subsidiary part of cummins which deals with used automotive components called
core.

RECON, itself, deals with its four sections in order

5
 Fig. 1.6 RECON Organisational Structure

1.6.1 Supply Chain

Supply chain management is the management of the flow of goods and services and includes
all processes that transform raw materials into final products. It involves the active
streamlining of a business's supply-side activities to maximize customer value and gain a
competitive advantage in the marketplace.

SCM represents an effort by suppliers to develop and implement supply chains that are as
efficient and economical as possible. Supply chains cover everything from production to
product development to the information systems needed to direct these undertakings.

1.6.2 Maintenance
Maintenance management is the process of maintaining a company’s assets and resources.
The purpose is to ensure that production proceeds efficiently and that resources are used
effectively.

Maintenance management is one of those aspects of managing a company that is usually not
explored in depth. People outside of the maintenance industry may not realize how much time

6
and effort go into making the flow of products through supply chains to the general world.
Let’s go in-depth on these important processes and understand why they are important.

1.6.3 Quality Control

Quality control (QC) is a process through which a business seeks to ensure that product
quality is maintained or improved. Quality control requires the business to create an
environment in which both management and employees strive for perfection. This is done by
training personnel, creating benchmarks for product quality and testing products to check for
statistically significant variations.

1.6.3 Product Engineering

Product engineering refers to the process of designing and developing a device, assembly, or
system such that it be produced as an item for sale through some production manufacturing
process. Product engineering usually entails activity dealing with issues of cost, productibility,
quality, performance, reliability, serviceability, intended lifespan and user features. These
product characteristics are generally all sought in the attempt to make the resulting product
attractive to its intended market and a successful contributor to the business of the
organization that intends to offer the product to that market.

1.7 Cummins Recon Products

Different components which are re-machined at Recon by means of different Salvages are:
1. Turbocharger
2. Lube oil pump
3. Water pump
4. Cam and follower
5. Cylinder head

1.7.1 Turbocharger
Turbochargers are centrifugal compressors driven by an exhaust gas turbine and employed in
engines to boost the charge air pressure. Turbocharger performance influences all important
engine parameters, such as fuel economy, power, and emissions. It is important to understand

7
a number of fundamental concepts before moving on to a more detailed discussion of
turbocharger specifics.

Fig. 1.7 Turbocharger

A turbocharger consists of a compressor wheel and exhaust gas turbine wheel coupled
together by a solid shaft and that is used to boost the intake air pressure of an internal
combustion engine. The exhaust gas turbine extracts energy from the exhaust gas and uses it
to drive the compressor and overcome friction. In most automotive-type applications, both the
compressor and turbine wheel are of the radial flow type. Some applications, such as medium-
and low- speed diesel engines, can use an axial flow turbine wheel instead of a radial flow
turbine.

1.7.2 Lube Oil Pump

Lubricating oil pumps are used to supply oil to lubrication points, e.g. for plain bearings. In
the case of circulation lubrication, the lubricating oil pump takes in an amount of oil from a
reservoir, forces it through the lubrication points and then feeds it back to the reservoir. Gear
pumps, which are able to generate high static pressure in the lubricating oil system, are
preferably used for this purpose.

8
 Fig. 1.8 Lube Oil Pump

In a fresh oil or economy lubrication system, each lubrication point is supplied with a quantity
of oil adequate for its needs. Special piston pumps are usually required for this purpose.

1.7.3 Water Pump

A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical
action, typically converted from electrical energy into Hydraulic energy. Pumps can be
classified into three major groups according to the method they use to move the fluid: direct
lift, displacement, and gravity pumps.

Fig. 1.9 Water Pump

9
Pumps operate by some mechanism (typically reciprocating or rotary), and consume energy to
perform mechanical work moving the fluid. Pumps operate via many energy sources,
including manual operation, electricity, engines, or wind power, and come in many sizes,
from microscopic for use in medical applications, to large industrial pumps.

1.7.4 Cam and Follower

A cam follower, also known as a track follower, is a specialized type of roller or needle
bearing designed to follow cam lobe profiles. Cam followers come in a vast array of different
configurations, however the most defining characteristic is how the cam follower mounts to
its mating part; stud style cam followers use a stud while the yoke style has a hole through the
middle.

Fig. 1.10 Cam and Follower

1.7.5 Cylinder Head

In an internal combustion engine, the cylinder head (often informally abbreviated to just head)
sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder,
forming the combustion chamber. This joint is sealed by a head gasket. In most engines, the
head also provides space for the passages that feed air and fuel to the cylinder, and that allow
the exhaust to escape. The head can also be a place to mount the valves, spark plugs, and fuel
injectors.

10
 Fig. 1.11 Cylinder Head

A cylinder head is the top of the region in an internal combustion engine. Today it is
commonly molded aluminum. The head bolts to the engine block. The head includes valves,
plugs, internal passages for fuel, intake, exhaust, and cooling. The cylinder heads can take on
various shapes. The Dodge and Ram have hemi-shaped cylinder heads as an option.

11
 Chapter 2
Project Analysis

2.1 Literature Review

1. Kenneth J. Liszka, Downers Grove, 2000, “Welding method for cylinder head Repair”,
General Motors Corporation, Detroit.

Summary: The present invention provides improvements in the procedures of the prior
process which have provided more consistent and dependable rebuilt cylinder heads. Rebuilt
heads made according to the invention provide metallographic structure comparable to new
cylinder heads and thereby improve durability of the resulting rebuilt cylinder heads. The
improved method according to the invention includes the prior steps of: determining the
locations of any cracks and rejecting any head with cracks in the fire face or barrel that go
through to the water jacket; placing each non-rejected head in an individual insulated oven
having an insulated lid; preheating the head in the oven with a gas flame to a suitable
temperature for welding; building up the entire fire face with weld metal applied by
oxyacetylene welding; oxy acetylene welding the cracks in the head while maintaining the
preheat temperature and protecting the valve seats and injector well from contact with molten
weld metal; after welding, encapsulating the head in the oven with the lid in place and
allowing to cool; and rough machining the fire face and valve guides and inspecting for
remaining cracks prior and to finish machining.[1]

2. Allyn P. Bock, West Lafayette, IN (US), “Sealing Fail Leakage Control in a cylinder head
Joint”, 2003, Caterpillar Inc., Peoria, IL (US).

Summary: This invention relates to a cylinder head Sealing System and more particularly to a
cylinder head Sealing System having a leak path which enables fluids to flow externally of the
cylinder head joint during a gasket Seal failure. A cylinder head Sealing System having a fail
Safe leakage control System. The fail Safe leakage control System provides a leakage fluid
path which allows any Sealed fluid to leak externally from a cylinder head joint and not
contaminate any other Vital fluids. This feature permits the engine to "limp home” or continue
operation until a permanent repair can be made to the engine. Thus, when a Seal of the

12
internal combustion engine fails, the fluid may flow within the fluid leakage paths externally
from the cylinder head joint which prevents the fluid from flowing within the cylinder or
other engine ports and contaminating the fluids therein.[2]

3. Jean-Francois Conte, Rhone, 1999, “Cylinder Head Gasket for Internal Combustion
Engines”. Henri Carles, Les Paris, Loisieux, Savoie,

Summary: The present invention has the aim of achieving an improved cylinder head gasket
which avoids the above disadvantages, which is of high performance, and of which the
reliability is much superior to that of cylinder head gaskets achieved hitherto. A cylinder head
gasket according to the invention comprises essentially three flat metal foils held against one
another, and it is characterized in that the sealing around the oil and water passage openings is
achieved by means of elastomeric bands attached to the central metal foil, the exterior foils
stopping short of the zones of the central metal foil which carry the bands. According to an
additional characteristic of the in venation, each elastomeric band comprises two beads which
each extend on one of the large faces of the central metal foil and which have a thickness
slightly greater than that of the external metal foils. According to an additional characteristic
of the in vention, in the case of two passage openings very close to one another, the external
metal foils are interrupted in the Zone situated just between the two passage open ings in
question. According to an additional characteristic of the in vention, around the flanges of the
cylinder linings the central metal foil is set back from the external metal foils. Gas tightness is
ensured by a metal ring having on the one hand a thick corrugated interior portion, and on the
other hand a thin external portion, or lip, located between the two external metal foils.
Circular escape channels are defined between the edges of the external metal foils and the
outer edges of the thick interior portion of the metal ring.[3]

4. Eugene Rosenberg, Haworth, N.J., 1996, “Process for Renewing Cylinder head”.

Summary: A process for renewing a cylinder head, preferably cast aluminum water cooled
cylinder head from a used condition to a rebuilt condition suitable for reuse. In a qualifying
stage the used cylinder head is stripped of removable parts, inspected, heat treated for
cleaning and stress relieving purposes, and then pressure tested to detect leaks through cracks
or excessive porosity. If cracks are located, the cylinder head passes through a reconstruction
stage wherein cracked areas are re moved and replaced by welded material, recon toured and

13
preferably again pressure tested. A cylinder head which did not need reconstruction (or after
reconstruction) then passes to the rebuilding stage where it is essentially machined and
component parts replaced. Included in the rebuilding stage is a line-boring and surface gasket
facing procedure for eliminating the adverse effects of war page and a vacuum impregnation
step to seal the pores of the cylinder head.[4]

5. M. Chamim, Triyono, and Kuncoro Diharjo, 2005, “Effect of Electrode and weld current
on the physical and mechanical Properties of cast Iron Welding”, Sebelas Maret University,
Surakarta.

Summary: Metal casting industry will repair the products are defective. The repair process is
often done using a Shielded Metal Arc Welding (SMAW). Preheat and post-weld heat
treatment method can overcome the problem of welding cast iron. However, many of the local
foundry industry does not use this method. The main problem of the method relates to the
problem of cost and process. The results of testing Scanning Electron Microscopy (SEM),
gray cast iron welding seen to have an important problem in the PMZ and HAZ. Hard and
brittle phase formations during solidification process and after solidification formation
eutectoid is carbide and marten site. The formation of martensite and carbides is caused by the
high carbon content of cast iron. Consumable electrode with a nickel base material used for
the welding process without preheating and PWHT methods. Nickel as an austenite stabilizer
can pick up the carbon, so that the hard phase PMZ area can be reduced. Variations electric
current used to get good heat input in the welding area so that nickel can diffuse well.[5]

6. Nazem Habibpour, Ali Shafyei, Reza Amini Najafabadi3, 2016, “Effects of post-weld heat
treatment temperature on the microstructure and mechanical properties of welded A517-Gr.B
steel by SMAW method”, Shiraz, Iran

Summary: Welding residual stresses have consequences for the performance of welded
components. The remaining stresses can be reduced by post-weld heat treatment (PWHT). In
this study, A517-Gr.B steel specimens welded by shielded metal arc welding (SMAW) were
subjected to PWHT at 450 °C, 500 °C, 550 °C, and 600 °C to study the effects of these
temperatures on yield, tensile, bending, and impact strengths. The fracture surfaces of the

14
specimens heat treated at different temperatures were studied using the scanning electron
microscope (SEM). The results indicated that the optimum temperature for PWHT was below
500 °C. Higher PWHT temperatures increased yield strength, tensile strength, and ductility of
the weld piece but greatly decreased its bending weld strength.[6]

2.2 Problem Statements

The Cylinder Head is not only a very important part of your engine, but also one of the most
expensive parts of the vehicle's engine due to its complex structure. Since the cylinder head is
exposed to very high temperatures during the combustion process, it consists of resistant
aluminum alloys and light metals.

At the bottom, it is usually anchored directly to the crankshaft housing and closed at the top
with a valve cover. Depending on whether your vehicle has a diesel or gasoline engine, the
structure of the cylinder head differs.

WORK : The main task of the cylinder head is to close the combustion chamber of the engine
from the top. The upper part of the engine is called the cylinder head, while the lower part is
the engine block. The cylinder head sits on the engine and closes off the combustion chamber.
The gap that remains between the cylinder head and the engine is completed by the head
gasket.

Another task of the cylinder head is to ensure the constant lubrication of the cylinder. If the
cylinders are not well-oiled, a smooth operation of the engine is not possible, which is why
the cylinder head is an indispensable part of the function of the engine.

Fig. 2.1 Defective Cylinder Head

15
DEFECTS : Unfortunately, the complex structure of the cylinder head and its numerous tasks
make it prone to defects. The most common defect is a leaking cylinder head gasket, which is
caused by an increased abrasion. See more in our blog post on the signs of a defective head
gasket.
There can also be defects on the cylinder head itself, for example, by the high temperatures
and strong vibrations in a running engine. This can lead to cracks in the material of the
cylinder head.

This project deals with a very rare, but very important defect that occurs on exhaust valve of
the cylinder head.

SALVAGE : Salvage is simply a keyword used at Cummins as a general term which means a
method of repair. Many defects can require a salvage of the cylinder head, which can be very
expensive. Since the cylinder head is installed in the engine, extensive work on this engine
component is associated with a repair or a restoration.
In most cases, the cylinder head must first be removed and then ground flat after a repair, as
this is the only way to ensure that it closes the lower part of the engine correctly.
An exchange of the cylinder head is only due in rare cases. Mostly, cylinder head defects
relate to easily replaceable parts, such as the valves.

Cracks typically form when a cylinder head undergoes too much thermal stress. Loss of
coolant, severe overheating as well as sudden changes in operating temperature from hot to
cold can all create the kind of conditions that cause cracks to form.

When metal is heated it expands. Aluminum expands at nearly twice the rate of cast iron,
which creates a mismatch in expansion rates on bimetal engines with aluminum heads and
cast iron blocks. Even so, the heads are designed to handle a certain amount of normal
expansion. But elevated operating temperatures can push a head beyond its design limits
causing the metal to deform. This, in turn, may cause cracks to form as the metal cools and
contracts.

16
The process Flow Cylinder head in the Assembly Line at Cummins is as follows :

Core

A warehouse is a building for storing

goods. Generally used by
manufacturers, importers, exporters,
wholesalers etc.
Warehouse

A place where something that is not being

used is kept for future use. It is a place from
where different types of components can be
Store
issued according to the requirements.

Here the parts of Cylinder head such as

Disassembly Collet, retainer, spring, Valve guide, valve
drop, expansion plug, insert seat, injector
sleeve, dowel and Cross head Guide, O-
Ring, Plug Pipe and Screw Seal are
removed or disassembled.
Primary Cleaning

Shot Blasting – an Operation for forcibly

propelling a stream of abrasive materials
Shot Blasting and such as steel grit to smooth a rough
Crack Checking surface, Used for Aesthetic looks and
Shining.

Crack checking – Checking of any crack

present Visually by UV light.
Thread and Bore Cleaning of internal threads and bores
Cleaning with the help of Pneumatic mechanical
brush. Removal of any carbon, rust
scratches present.

17
 Retrieval or preservation of internal
Thread Salvaging threads parameters such as depth and
diameter of intake holes, threaded
holes, fuel manifold holes , rocker lever
housing mounting holes , injector
mounting holes etc.
Spot Facing
Mounting Holes

Grinding of combustion and rocker face

Milling to obtain required head height, surface
finish and surface flatness. A Muscle
cool oil is used for Lubrication in
milling process.

Secondary
Shots or any other foreign particle
Cleaning
inside Fuel gallery should be cleaned
if present. Magnetic Rod is used for
this checking.

Expansion Plug
Assembly
First Air is passed through all galleries
to check if it’s passing freely or not.
Next Pressure drop is checked over
Fuel, Water and fuel, water and oil gallery, if its OK
Oil Gallery Check Green color light is displayed by
machine.

Number Punching

Maintaining intake and exhaust

valve intrusion with the prefixed
limit. Checking of insert seat to
Insert Seat Pressing guide bore concentricity with the
and Grinding help of concentricity Gauge.

18
 Child Part such as Rotator, spring
and Retainer are Assembled at the
Rotator, Spring and designated part.
Retainer Assembly

Assembly of valve. Intake and

Valve Assembly Exhaust valve intrusion should be
within the limit. Dowel Pin height
should be checked.

Vacuum Test Vacuum should be created up to 20-

25Hg and should not drop below
8in/Hg within 3 sec. vacuum Test is
done by Vacuum Tester. White dot on
valves represent Vacuum test Pass.
Paint Booth

Oiling

Packaging of cylinder head carefully

in the Cardboard boxes along with
Packaging the Tags for the distribution process.

Fig. 2.2 Cylinder Head Line Process Flow

Cylinder heads were getting rejected at Cummins even after all the possible salvages done on
it, due to the following reasons :

19
 1. Heavy damage observed in gasket non contacting area (Zone -1 / localized near
exhaust port)

Fig. 2.3. Pitting Marks at the exhaust valve

This Gasket Non-contacting area near the exhaust port was termed as Zone-1.

2. Heavy damage, pitting, sealing marks, impression observed in gasket sealing

area (Zone -2 / widespread over the exhaust face)

Fig. 2.4. Damage Observed at the valve

This Gasket Sealing area near the exhaust port was termed as Zone-2. Zone 1 and Zone two
are defined in order to distinguish the defects.

20
 Fig. 2.5. Exhaust Face Defect Type

2.3 Objective
Our objective of this is to find the salvage technique for this defect .

21
 Chapter 3
Proposed methodology

All the core cylinder head which are rejected after being properly salvaged due to the pitting
marks are collected and then the following processes followed.

3.1 Process Flow

Fig. 3.1. Process Flow Chart for Zone 1

22
 Fig. 3.2 Process flow chart for zone 2

3.2 Steps involved

1. Place gasket in the exhaust valve

First, we need to identify the zones, i,e, pitting marks affected area by placing a gasket
in the exhaust valve. Then a nano fluid is sprayed over it. This nano fluid is actually
works as a contrast developer.

2. Remove Gasket
Then the gasket is removed. If the defect lies in the white area, send it for Grinding.
And if the defect lies outside the white area, send it for welding.

23
 Fig. 3.3. Exhaust Face Defect Type

3. Grinding Process

Grinding is an abrasive machining process that uses a grinding wheel as the cutting
tool. Grinding practice is a large and diverse area of manufacturing and tool making.
It can produce very fine finishes and very accurate dimensions; yet in mass production
contexts it can also rough out large volumes of metal quite rapidly. It is usually better
suited to the machining of very hard materials than is "regular" machining (that is,
cutting larger chips with cutting tools such as tool bits or milling cutters), and until
recent decades it was the only practical way to machine such materials as hardened
steels.

Fig. 3.4. Grinding Process

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 4. Welding Process

Welding is a fabrication or sculptural process that joins materials, usually metals or

thermoplastics, by using high heat to melt the parts together and allowing them to
cool, causing fusion. Welding is distinct from lower temperature metal-joining
techniques such as brazing and soldering, which do not melt the base metal.

Fig. 3.5. Welding Process

3.3 Welding of Cast Iron

Welding cast iron in house is possible—under certain conditions

Effective in-house welding of cast iron parts can save time and money—but there are
challenges. Welding failure can often result in cracking or other damage. If critical parts are
involved, it may be wise to seek the workmanship of a welding facility with experienced
welders to ensure a successful result.[9]

If welding is performed in-house, it is crucial to research the steps required to effectively

produce a welded part. Four key steps should be taken before getting started:

1. Identify the alloy

2. Clean the casting thoroughly

3. Select a pre-heat temperature

4. Select an appropriate welding technique

25
Before any welding project, be sure to clean the casting, pre-heat the alloy, and choose an
appropriate welding technique.

Identify the alloy :

Cast irons are a family of iron-carbon alloys. Their high carbon content (usually 2–4%) gives
cast iron its characteristic hardness. However, that hardness comes at the expense of ductility.
It is less malleable in comparison to steel or wrought iron. The heating and cooling cycles
during welding cause expansion and contraction in the metal, inducing tensile stress. Cast
irons do not stretch or deform when heated or stressed—instead, they crack—making them
extremely difficult to weld. This characteristic can be improved by adding different alloys.

Some cast iron alloys are easier to weld than others:

• Grey cast iron

Grey cast iron is the most common form of cast iron. Carbon precipitates out into graphite
flakes during manufacturing into either a pearlite or ferrite crystalline microstructure. It is
more ductile and weldable than white cast iron. However, it still poses a challenge to
prospective welders as the graphite flakes within grey cast iron can enter the weld pool to
cause weld metal embrittlement.

• White cast iron

White cast iron retains the carbon as iron carbide without precipitating it out as graphite. The
cementite crystalline microstructure is very hard and brittle. White cast iron is generally
considered unweldable.

• Ductile, nodular, or malleable iron

These cast irons are all less brittle due to microstructural differences due to manufacture. All
three have spheroidal carbon microstructures created by their unique manufacturing
processes.

The best way to determine whether you have white or grey iron is to check the original
specification. Spectrochemical analysis can provide this specification after the fact. When
these precise ways are not possible, there are a few ways to check in the shop.

26
Grey iron will show grey along a fracture point, due the the graphite in its microstructure.
White iron is whiter along a fracture due to the cementite. Unfortunately, the fracture test is
only useful if the welder knows that the material is either grey or white. These are older, more
traditional forms of cast iron. They are also more common in certain classes of goods.
However, ductile iron, a relative newcomer, is also quite white along fracture, and is much
more weldable.

Spark testing can also be used by an experienced metallurgist to try to determine type of iron.

Clean the Casting :

Regardless of the alloy, all castings must be properly prepared prior to welding. While
preparing the casting for welding, it is crucial to remove all surface materials. The casting
must be completely clean in the area of the weld. Remove paint, grease, oil, and other foreign
material from the weld zone. It is best to apply heat carefully and slowly to the weld area for a
short time to remove entrapped gas from the weld zone of the base metal.

A simple technique for testing the readiness of the cast iron surface is to deposit a weld pass
on the metal—it will be porous if any impurities are present. This pass can be grinded off, and
the process repeated a few times until the porosity disappears.
Pre Heat :

All cast irons are vulnerable to cracking under stress. Heat control is the single most important
factor in avoiding cracks.

A cast iron weld requires three steps:

• Pre-heating

• Low heat input

• Slow cooling

The primary reason for heat control is thermal expansion. When metal warms, it expands. No
stress is caused when an entire object warms and expands at the same rate, but stress will
build when heat is localized in a small heat-affected zone (HZ).

Localized heating causes restricted expansion—the HZ is contained by the cooler metal

around it. The degree of resulting stress depends on the thermal gradient between the HZ and

27
the casting body. In steel and other ductile metals, stress built by restricted expansion and
contraction is relieved by stretching. Unfortunately, this can cause cracking during the
contraction period since cast irons have relatively poor ductility. Pre-heating decreases the
thermal gradient between the casting body and the HZ, thereby minimizing the tensile stress
caused by welding. In general, higher temperature welding methods require a higher
temperature pre-heat. When adequate preheating is not possible, the best strategy is to
minimize heat input—select a low temperature welding process, and low melting point
welding rods or wires.

Cooling rate is another factor that has a direct impact on the stresses induced at the weld.
Rapid cooling causes contraction, which creates brittle, easily cracked welds. Contrastingly,
low cooling reduces hardening and contraction stress.

3.3.1 Welding Technique :

Welding techniques should be chosen based on their suitability to the cast iron alloy being
welded. The most common welding processes are stick, oxy acetylene, and braze welding.

Stick welding

Stick welding, also known as shielded metal arc welding or MMA, makes use of a
consumable electrode covered with a flux. Different types of electrode can be used depending
on the application, the colour match required, and the amount of machining to be done after
welding.

There are three main filler types that work well for cast iron stick welding:

• Cast iron covered electrodes

• Copper alloy electrodes

• Nickel alloy electrodes

Nickel alloy electrodes are the most popular for cast iron welding. According to New
Hampshire Materials Laboratory Inc., nickel-iron weld is stronger with a lower coefficient of
thermal expansion, reducing welding stresses and improving resistance to cracking.

An electric arc between the electrode and welding area melts the metals and causes fusion.
The arc should be directed at the weld pool, rather than at the base metal, as this will

28
minimize dilution. It is recommended to use the lowest current setting approved by the
manufacturer to minimize heat stress. Preheat pieces to at least 250°F prior to welds with cast
iron or copper electrodes. Nickel electrodes can be used without a preheat.

Stick welding uses different types of electrodes depending on the application, color match,
and amount of machining required after welding.

Oxy acetylene welding : Oxy acetylene welding also makes use of electrodes, but instead of
an arc generated by current, an oxy acetylene torch provides the energy for welding. Cast iron
electrodes, and copper zinc electrodes, are both suitable for oxy acetylene welding of cast
iron.

Care must be taken not to oxidise the cast iron during acetylene welding, as this causes silicon
loss and the formation of white iron in the weld. The welding rod should be melted in the
molten weld pool, rather than directly by the flame, to minimize temperature gradients.

Braze welding : Braze welding is a common method for joining cast iron parts due to the
minimal impact on the base metal itself. A welding rod provides the filler that adheres to the
cast iron surface. Because of the lower melting point of the filler compared to the cast iron,
the filler does not dilute with the cast iron but adheres to the surface.

Cleanliness of the surface is critical for this weld technique since the join is dependent on the
quality of the filler wetting the surface of the base metal. According to Machine Design, using
flux to prevent the formation of oxides during brazing is common. It is a liquid that promotes
wetting, which lets the filler flow over the metal parts to be joined. It also cleans the parts of
oxides so that the filler bonds more tightly to the metal parts. In addition, fluxes are used in
welding to clean the metal surfaces.

3.3.2 Finishing

Cracking usually occurs during the thermal contraction phase—tensile stress builds as the
weld cools and contracts. If the stress reaches a critical point, the weld cracks.

The chances of cracking can be decreased by applying a compressive stress to oppose tensile
stress during cooling. Welders use a technique called peening (moderate strikes with a ball-
peen hammer) to a deformable weld bead while the weld is still soft. Peening decreases the

29
risk of cracking in the weld and HZ, but should only be attempted when working with
relatively ductile weld metal.

The final step of the weld is cooling control. This process uses insulating materials to slow
cooling as much as possible, or applies periodic heat to the weld to slow down the natural
cooling process.

3.4 Shielded Metal Arc Welding

Shielded metal arc welding (SMAW), also known as manual metal arc welding (MMA or
MMAW), flux shielded arc welding or informally as stick welding, is a manual arc welding
process that uses a consumable electrode covered with a flux to lay the weld.

Fig. 3.6 Shielded Metal Arc Welding

An electric current, in the form of either alternating current or direct current from a welding
power supply, is used to form an electric arc between the electrode and the metals to be
joined. The workpiece and the electrode melts forming a pool of molten metal (weld pool)
that cools to form a joint. As the weld is laid, the flux coating of the electrode disintegrates,
giving off vapours that serve as a shielding gas and providing a layer of slag, both of which
protect the weld area from atmospheric contamination.

Because of the versatility of the process and the simplicity of its equipment and operation,
shielded metal arc welding is one of the world's first and most popular welding processes. It
dominates other welding processes in the maintenance and repair industry, and though flux-
cored arc welding is growing in popularity, SMAW continues to be used extensively in the
construction of heavy steel structures and in industrial fabrication. The process is used

30
primarily to weld iron and steels (including stainless steel) but aluminium, nickel and copper
alloys can also be welded with this method.[7]

3.4.1 Operation

Fig. 3.7 Welding Operation

3.4.1.1 SMAW weld area : To strike the electric arc, the electrode is brought into contact
with the workpiece by a very light touch of the electrode to the base metal. The electrode is
then pulled back slightly. This initiates the arc and thus the melting of the workpiece and the
consumable electrode, and causes droplets of the electrode to be passed from the electrode to
the weld pool. Striking an arc, which varies widely based upon electrode and workpiece
composition, can be the hardest skill for beginners. The orientation of the electrode to
workpiece is where most stumble, if the electrode is held at a perpendicular angle to the
workpiece the tip will likely stick to the metal which will fuse the electrode to the workpiece
which will cause it to heat up very rapidly. The tip of the electrode needs to be at a lower
angle to the workpiece, which allows the weld pool to flow out of the arc. As the electrode
melts, the flux covering disintegrates, giving off shielding gases that protect the weld area
from oxygen and other atmospheric gases. In addition, the flux provides molten slag which
covers the filler as it travels from electrode to the weld pool. Once part of the weld pool, the
slag floats to the surface and protects the weld from contamination as it solidifies. Once
hardened, it must be chipped away to reveal the finished weld. As welding progresses and the
electrode melts, the welder must periodically stop welding to remove the remaining electrode
stub and insert a new electrode into the electrode holder. This activity, combined with
chipping away the slag, reduces the amount of time that the welder can spend laying the weld,

31
making SMAW one of the least efficient welding processes. In general, the operator factor, or
the percentage of operator's time spent laying weld, is approximately 25%.[7]

3.4.1.2 SMAW system setup : Shielded metal arc welding equipment typically consists of a
constant current welding power supply and an electrode, with an electrode holder, a ground
clamp, and welding cables (also known as welding leads) connecting the two.

3.4.1.3 Power supply : The power supply used in SMAW has constant current output,
ensuring that the current (and thus the heat) remains relatively constant, even if the arc
distance and voltage change. This is important because most applications of SMAW are
manual, requiring that an operator hold the torch. Maintaining a suitably steady arc distance is
difficult if a constant voltage power source is used instead, since it can cause dramatic heat
variations and make welding more difficult. However, because the current is not maintained
absolutely constant, skilled welders performing complicated welds can vary the arc length to
cause minor fluctuations in the current

3.4.1.4 Various accessories for SMAW : The choice of electrode for SMAW depends on a
number of factors, including the weld material, welding position and the desired weld
properties. The electrode is coated in a metal mixture called flux, which gives off gases as it
decomposes to prevent weld contamination, introduces deoxidizers to purify the weld, causes
weld-protecting slag to form, improves the arc stability, and provides alloying elements to
improve the weld quality. Electrodes can be divided into three groups—those designed to melt
quickly are called "fast-fill" electrodes, those designed to solidify quickly are called "fast-
freeze" electrodes, and intermediate electrodes go by the name "fill-freeze" or "fast-follow"
electrodes. Fast-fill electrodes are designed to melt quickly so that the welding speed can be
maximized, while fast-freeze electrodes supply filler metal that solidifies quickly, making
welding in a variety of positions possible by preventing the weld pool from shifting
significantly before solidifying.

Welding process involves the identification of the core by placing gasket template. This
process is same as for the zone 1. After which the nano fluid is sprayed over the gasket. Then

32
the gasket is removed. If the defects lies on the gasket ceiling area then grind and weld the
prepared groove.[7]

Fig. 3.8 Cylinder Head - Just after Welding

3.5 Finishing

After welding, milling is done in order to get perfect surface finish.

Fig. 3.9 Surface Finishing

33
 Chapter 4
Result and Discussion

During the trial phase of proposed salvage over 20-cylinder heads, out of which 17 came out
to be clean that is tested ok whereas 3 cylinders head were rejected due to following reasons:
• Distorted geometry
• Cracks
• Improper groove geometry

Certain measures must be adopted in order to minimize the defects in salvage which include:
• Proper placement of gasket over exhaust face for marking
• Grinding must pe properly executed in order to make dimensional groove
Controlled preheating and proper precleaning must be done in order to avoid cracks
and distortions

4.1 Limitations of salvage

Since the methodology is carried by certain number of process that is identification of zone,
groove preparation, preheating, precleaning, welding, again grinding and finally surface
finishing by milling this is prolonged process just for one cylinder head.

4.2 Conclusion

The proposed salvage is tested and does not require Additional machinery or resources thus it
is approved by Product Engineering Department and soon to be used in regular production
schedule.

Since the salvage is cost efficient but at the same time it is time consuming thus recurring
efforts must be made in order to improvise the salvage, minimize the defects and reduce the
process time

34
 Chapter 5

Future Scope

This salvage technique has been approved by the officials of the firm and they have accepted
this project. They declared that this salvage technique will be adopted in the future to deal
with this defect.

Due to this, Cummins now no longer needed to reject these type of cylinder heads. And this
will add up a huge profit to this firm in the near future.

Yes, to be honest this salvage technique is time consuming. So may be in the future there is a
scope of lesser time consuming technique.

35
 Bibliography

1. Kenneth J. Liszka, Downers Grove, 2000, “Welding method for cylinder head Repair”,
General Motors Corporation, Detroit.

2. Allyn P. Bock, West Lafayette, IN (US), “Sealing Fail Leakage Control in a cylinder head
Joint”, 2003, Caterpillar Inc., Peoria, IL (US).

3. Jean-Francois Conte, Rhone, 1999, “Cylinder Head Gasket for Internal Combustion
Engines”. Henri Carles, Les Paris, Loisieux, Savoie,

4. Eugene Rosenberg, Haworth, N.J., 1996, “Process for Renewing Cylinder head”.

5. M. Chamim, Triyono, and Kuncoro Diharjo, 2005, “Effect of Electrode and weld current
on the physical and mechanical Properties of cast Iron Welding”, Sebelas Maret University,
Surakarta.

6. Nazem Habibpour, Ali Shafyei, Reza Amini Najafabadi3, 2016, “Effects of post-weld heat
treatment temperature on the microstructure and mechanical properties of welded A517-Gr.B
steel by SMAW method”, Shiraz, Iran

7. Rao,P.N., 2017,Manufacturing Technology-Vol. II, 3rd ed. , Tata McGraw-Hill Education,

New Delhi, ND, Chap.2.

8. https://www.cummins.com/company/overview

9.https://scholar.google.com/scholar?hl=en&as_sdt=0,5&qsp=1&q=cylinder+head+joint+%2
2leakage+control%22&qst=bh#d=gs_qabs&u=%23p%3DRarH-Um3i5QJ

36