Automobile Maintenance : Changing The Front Shock Absorbers

Had to change my worn-out front shock absorbers (or dampers) for the bi-annual test of vehicle. Worn-out shocks had lowered the vehicle and had also modified the camber angle of tires. Being a purely mechanical job, I decided to do it myself following the instructions of the service manual. This work was performed on the Renault Espace II.

Unmanned Air Vehicles (Old Articles Series-6)

Old Articles Series Part-6. This article was published in a late 2003 issue of the Defence Journal (of Pakistan). Please note that no jingoism was meant, the author wrote it from defence point of view. Author supports peace and cordial relations among countries of the South Asia. Also the information contained should be viewed in the context of the time period in which the article was written or published.

Unmanned Air Vehicles (UAVs)

Columnist Syed Imran Shah makes a thorough study of UAVs

The Need for UAVs

Military commanders have always wanted to observe the movements and deployments of enemy formations. Timely intelligence about the activities of the opponent and situational awareness have always been the key to success. For this purpose, many arrangments were done throughout human history like the construction of observation towers, use of air balloons, manned aircraft of first generation, dedicated reconnaissance aircraft, space satellites and unmanned or uninhabited air vehicles.

UAVs are nowadays used for surveillance and observation, artillery fire direction for naval guns and army batteries, maritime patrol, border patrol, checking illegal immigration and drug smuggling, electronic intelligence, communications relay, search and resuce operations and weather data collection.

Air Defence Of Pakistan Part -II (Old Articles Series - 5)

Old Articles Series Part-5. This article was published in the July 2003 issue of the Defence Journal (of Pakistan). Please note that no jingoism was meant, the author wrote it from defence point of view. Author supports peace and cordial relations among countries of the South Asia. Also the information contained should be viewed in the context of the time period in which the article was written or published.

Air Defence of Pakistan Part 2

The PAF’s defensive capability

SYED IMRAN SHAH

In the recent wars, we can see an identical and regular pattern of air operations starting from the suppression of air defences and attacks by stealth bombers and cruise missiles to the final strikes and bombing. We shall try to analyse these operations.

We shall study both the air defence ground environment and the role of air force.

My previous article on the same topic was more about the ground-based air defence whereas this article is focusing on air defence by air force fighter jets and hence the main theme is air superiority operations. Here the main focus still remains the threat faced by Pakistan due to relentless military build up across its eastern border.

Surface to Surface Missiles (Old Articles Series-4)

Old Articles Series Part-4. This article was published in the May 2003 issue of the Defence Journal (of Pakistan). Please note that no jingoism was meant, the author wrote it from defence point of view. Author supports peace and cordial relations among countries of the South Asia. Also the information contained should be viewed in the context of the time period in which the article was written or published.

SURFACE-TO-SURFACE MISSILES

Columnist IMRAN SHAH details the characteristics.

Introduction

Surface-to-surface missiles have a role of projecting offensive power in the strategic sense. There are two types of surface-to-surface missiles. The first is cruise missiles and other is the ballistic missile. Cruise missile is like an aircraft with wings and a jet propulsion system. Ballistic missile is a missile that does not rely on lift provided by wings and it flies under the action of gravity after the thrust termination. The world’s first cruise missile was V-1 Doodlebug and the first ballistic missile was V-2. Both V-1 and V-2 were made and used by Germany in World War 2. They were relatively inaccurate and were used as terror weapons and had area targets like cities. London was the main target for these new weapons. In WW2, there was no counter to ballistic missiles but British fighters succeeded in intercepting some cruise missiles.

Anti-Ship Missiles: India and Pakistan (Old Articles Series-3)

 Old Articles Series Part-3. This article was published in the February 2003 issue of the Defence Journal (of Pakistan). Please note that no jingoism was meant, the author wrote it from defence point of view. Author supports peace and cordial relations among countries of the South Asia. Also the information contained should be viewed in the context of the time period in which the article was written or published.

Anti-Ship Missiles: India and Pakistan

Columnist Syed Imran Shah discusses the acquirement/development of these missiles in South Asia.

Background

Anti-ship missiles have come to play a pivotal role in deciding the outcome of a naval battle. Let’s take a look at the past. In 1971 war, Pakistan Navy suffered due to SS-N-2 Styx anti-ship missiles. The minesweeper PNS (Pakistan Naval Ship) Muhafiz and PNS Khyber were sunk by Styx anti-ship missiles fired from Missile Boats of Indian Navy.

In 1967, the Egyptian Navy used these Styx missiles to sink the Israeli destroyer Eliat. In the Falklands War in 1982, Argentinean Exocet missiles hit three British ships and in Iran-Iraq war throughout the mid-1980s, Iraqi missiles sank at least five Iranian vessels. In May 1987, two AM-39 Exocets fired from an Iraqi Mirage severely damaged the USS Stark. All these conflicts show the awesome prowess of the modern anti-ship missiles, especially the air-launched ones. The unequivocal demonstration of the Exocet’s effectiveness made it a ubiquitous weapon system. Thus, it has been proved time and again that anti-ship missile is a potent maritime strike weapon. Due to the long-range advantage of the anti-ship missiles, they shall be more instrumental in sinking the ships than torpedoes in a naval war. Club missiles, Kh-35 Uran, Sea Eagle and P-20 are the main anti-ship missiles (AShMs) of Indian Navy. AM-39 and SM-39 Exocets, R/UGM-84 Harpoons, HY-1s and C-802s are the anti-ship missiles of Pakistan Navy.

Counter-Air Operations (Old Articles Series-2)

 Old Articles Series Part-2. This article was published in the December 2002 issue of the Defence Journal (of Pakistan). Please note that no jingoism was meant, the author wrote it from defence point of view. Author supports peace and cordial relations among countries of the South Asia. Also the information contained should be viewed in the context of the time period in which the article was written or published.

Counter-Air Operations

Columnist Syed Imran Shah gives an analysis of future air operations in light of past experience and modernisation of equipment.

Introduction

Counter-air is an air operation of a tactical air command conducted to attain and maintain a desired degree of air superiority by the destruction and neutralization of enemy forces. Both air-offensive and air-defensive actions are involved. But we shall focus on air-offensive actions and counter-air interdictions.

Interdiction is an air-to-ground operation behind the enemy lines to divert, disrupt, delay or destroy the enemy’s surface military potential before it can be used effectively against friendly forces. In modern warfare, it typically refers to the use of air power to destroy bridges, major railway junctions, or other choke points inside enemy territory, thus preventing not only supplies, but also reinforcements from reaching the battle area. Today, interdiction is carried out mostly by Fighter-Bombers of an air force.

Here, we discuss the risks and obstacles involved in interdiction missions, and accordingly the qualities required in the strike aircraft, with special focus on India and Pakistan.

The Air Defence of Pakistan (Old Articles series- 1)

Old articles series Part 1. This article was published in October 2002 issue of the Defence Journal (of Pakistan). Please note that no jingoism was meant, the author wrote it from defence point of view. Author support peace and cordial relations among countries of the South Asia. Also the information contained should be viewed in the context of the time period in which the article was written or published.

The Air Defence of Pakistan

Columnist Syed Imran Shah suggests high-tech modernisation.

INTRODUCTION

The dominant role of air power in modern warfare has been clearly established. A nation unable to defend itself against air assaults of its adversary would be placed at a serious disadvantage in any future conflict. Air defence especially for nations under threat of military aggression thus becomes a vital element in its overall defence strategy.

India has a potent air power strike element that poses a serious threat to the security of Pakistan in any armed conflict. To be able to employ this offensive potential, the Indian Air Force would first have to overcome and degrade Pakistan’s air defence network. A strong and resilient air defence system then becomes imperative for Pakistan in order to prevent the Indian juggernaut. This article will address the air defence issues in general with special focus on Pakistan.

Automobile Maintenance : Brake Caliper Rebuild



If the brakes of your vehicle are sticking to the wheels (infact to the brake rotors), the acceleration of your vehicle would be affected alongwith an increased fuel consumption. Brakes stick when the driver is not pushing on the brake pedal but the wheel is still held by the brake pads. It can be easily found out by jacking up the vehicle and rotating the wheels with hands. If the wheel sticks and is hard to rotate, you need to repair your brake system for that particular wheel. The cause may be sticking slider bolts, stuck caliper piston or jammed flexible brake hose.

Another cause of sticking brakes is the overfilling of the brake fluid reservoir. In my case, a professional workshop had overfilled the brake reservoir and there was no space for the brake fluid to go once the brakes were released. Therefore, do not fill the brake reservoir beyond the maximum mark, or ideally keep the level between the mini and maxi marks.

I am covering all three cases here. Here I am doing it on the front caliper of the Renault Espace with 2.2L  J7T engine. After the necessary diagnostic, if you are replacing your flexible brake hose,  then cut a piece of old hose to be used for pushing out the caliper piston.

Automobile Maintenance : Spark Plug Wires

Spark plug wires are also called Ignition wires or High-Tension leads or Ignition leads etc. These wires carry the high-voltage power from the coil to the individual cylinders of the engine. With Coil-On Plug (COP) Ignition systems becoming the standard, ignition wires have now being reduced to the repair market. If your petrol engine (if it uses ignition wires) is hard to start or misfires during driving , the first thing to check should be the spark plug wires. After visual inspection for cracks etc in the rubber / silicon insulation, do a continuity test with multimeter. The resistance or continuity test would not indicate anything on the state of the insulation of the wires, which needs to be tested separately. One way of doing it has traditionally been starting the engine, looking at the plug wires in the dark and noting any sparks or arcs from wires to the other parts or between wires themselves. Another way to test the wire is with a variable-gap spark tester at various engine rpms. This variable-gap spark tester replaces the spark plug and is attached to the wire. If there is a spark at a wide-gap (at least double the spark plug gap), then wires are ok.  

Electrical Power of Heating Elements : High Resistance or High Current



Many people intuitively think that electric devices with heating elements have a high resistance, i.e., that they get heated due to higher resistance of the conductor element. In the university days, one of our friends from Electrical Engineering (Syed Atif Shah) told us that it was not the case and that devices with higher power rating actually have a low-resistance. The formula for electric power is P = I*I*R where P is for power, I for current and R stands for resistance. Current is squared and therefore it plays the major role. I decided to put this theory to the test and find out for myself. There are many electrical devices lying around and one can easily find out. 

Automobile Maintenance : Valve Job (Cylinder Head)

If the cylinder head has been removed from the engine due to any reason like doing a head gasket job, then it is an ideal time to do a valve job and change valve oil seals.  Valve seals also need to be changed if the engine is burning / consuming oil abnormaly. Valves seal the cylinder during the compression and power strokes. With time, the valve seats get pitted with carbon deposits (especially the exhaust valve seat) and need to be ground (verb grind) to improve sealing for better compression and torque. The valve job shown here was performed on the Renault J7T petrol engine  (designed and manufactured by Francaise de Mécanique).

Automobile Maintenance: Engine Tune-Up - Air Filter, Spark Plugs, Crank Sensor, Idle Air Valve

Note :  This post is not about "tuning", it is about tune-up.  The two should not be confused.

Here I discuss four elements of engine tune-up namely air filter, spark plugs, crank sensor and idle air valve. Of course there are other things like ignition wires that need to be checked or replaced but that would be covered in other posts. 

If you have to replace your air filter, why not replace it with a filter with low-resistance to air flow? Some filters enclose their paper filtering element with perforated metal sheets, which is not ideal for free air flow. A wire gauze air filter is shown below. It offers less resistance to the air flow than a filter with a perforated metal sheet.

Socket Types for Ratchets

In professional workshops or backyard week-end repairs, we need to use sockets with ratchets to install or remove fasteners (bolt or nut).  These sockets come in various sizes and types.

From left to right, the image below shows the three main socket types, i.e., 12-points socket, 6-points socket and a side-grabbing 6-side socket. The 8-points sockets,  used with rectangular nuts, are not so common.   

Steel Bolt Strength Markings

When doing automobile repairs or other machinery maintenance, we often need to install or replace the bolts and nuts. Each bolt is built to a specific standard regarding its tensile strength (the load that it would carry).  People usually do not pay attention to the strength of the bolt when using them. For critical applications, proper strength class bolts need to be used. Both grades (in USA) and classes are used for strength classification. Here we would consider metric system (classes).

Repairing Fastener Threads

It often happens that we  have a fastener (bolt or nut) with damaged threads. Sometimes during installtion, the fastener threads get damaged. If the damage is not serious and  not on the load-bearing threads, then the threads can be repaired and fastener reused. Here is a fastener with partially damaged threads. Here we would only consider right-hand threads.

Automobile Maintenance : Fuel Rail Thermal Insulation

Temperature of the fuel affects both the power and fuel consumption of an automobile. Both fuel injectors and fuel pump are cooled by the passage of fuel through them and if the fuel itself is hot, cooling of injectors would be affected. Colder fuel also gives slightly more power (but a bit higher fuel consumption). Additionally more ignition advance can be used as compared to hotter fuel.  If you are planning on using ethanol fuel, then this procedure is not recommeneded.

As we start the engine, its temperature rises. Gradually, the engine starts to warm up all accessories under the hood. This includes the fuel rail too. If the fuel rail is metallic (which is usually the case), the fuel will  be heated too. Petrol or Gasoline has a much higher evaporation rate as compared to diesel and if there is a leak in the fuel vapour recovery system, fuel vapours would be lost. Also if the fuel tank cap is not tight enough, vapours would leak from the tank at a  rate proportional to the temperature of the fuel. Additionally, if the fuel pump starts to lose pressure, then vapour lock can occur in the fuel system if fuel is hot. If the fuel rail is insulated, fuel can be kept at a lower temperature. Here is an image of Renault J7T (designed and manufactured by Francaise de Mécanique) engine's fuel rail with rail-holding bolts removed.

Note: Thermal insulation of the fuel rail was officially used by Renault for J7T-760 engine of Safrane car. 

Graveyards and Indispensable People

New proverb: "Jet engines can't be made in a country where graveyards are full of indispensable people".

Indispensable or dispensable? Even in the educated circles of Pakistan, the thinking seems to be inclined in favour of "dispensable". The phrase "Graveyards are full of indispensable people" is often used by bosses for certain motives but sometimes it can be detrimental to the intellectual growth of individuals. It is time to scrutinize this phrase.

Great Game of the South Asia

Recently (June 2015) news reports circulated in the media that Indian Armed Forces have launched an operation in Myanmar (formerly Burma) against the insurgents of the North-East India. The insurgency in the North-Eastern India is not a new affair. It is now several decades old. The roots of this problem do not seem to be clear to the younger generation. The origin of this insurgency dates back to the 1800s.

Indigenous Aircrafts with Foreign Engines

Jet engine is a highly technical and complicated machine and is therefore mastered only by technically most advanced countries. It is also evident that aviation is one of the world's most important businesses and it is no surprise that the "business secrets" have been well-guarded. Jet engines are designed and manufactured mainly by USA, Russia, United Kingdom and France. Anyone aspiring to build an indigenous aircraft with gas turbine propulsion system has to buy engines from one of these four countries with some options in Canada. China has been designing and producing aircrafts (military and civil) for several decades but still has not succeeded in designing a reliable jet engine. Chinese fighter aircrafts are mostly equipped with licence-produced or imported Russian engines.