Automotive News

Posts Tagged ‘use’

The Engine

Technically speaking, your car’s engine is not a motor, although everyone uses the two words interchangeably. A “motor”converts electrical  energy into mechanical work such as the ecm and starter motor that cranks your engine. An “engine,” on the other hand, is a machine that converts heat energy into mechanical work. Your engine ecm does this by forcing the engine to burn gasoline inside its combustion chambers. When gasoline and air are mixed together in the right proportions (parts of air to one part gasoline is considered ideal) and ignited by a spark, the mixture explodes, creating tremendous heat and pressure. Although, combustion occurs in a split second, the ecm insures it does so in a controlled manner. When the spark ignites the mixture, a “flame front” sweeps out from the point of ignition like a rapidly expanding balloon until all the fuel mixture is consumed. This causes a sharp rise in cylinder pressure, and ecm performance  which pushes the piston down and turns the crankshaft. Thus, heat energy is transformed into useful mechanical work to power your car down the road. Pressing down on the accelerator pedal opens up the engine throttle, which allows more air and fuel to be drawn into the engine. This increases the density of the fuel mixture in each of the engine’s cylinders, which in turn increases the intensity of cylinder pressures when the mixture is ignited. As a result, the engine ecm develops more power, allowing it to either run faster or work harder, depending on the load. Let off on the accelerator pedal and the amount of air and fuel are decreased. Cylinder pressures drops and the engine ecm slows down.

In a way, you can think of an internal combustion engine as an air pump. The ecm sends signals to the throttle which allows it to pump more air through itself, and the greater the volume of air (and fuel, the greater the ecm output. That’s why bigger engines require a high performance ecm to produce more horsepower than smaller ones. They have a greater pumping capacity. Unfortunately, internal combustion engines are not very efficient when it comes to making good use of the heat energy produced by combustion. Only about a third of the heat energy is actually used to drive the vehicle. Nearly a third is lost when the hot exhaust gases exit
out the tailpipe. By the time the piston reaches the lower limit of its travel. cylinder
pressure has dropped considerably from its peak which occurred shortly after ignition.
The engine ecm has gotten all it can from the expanding combustion gases, yet heat energy remains which must now be dumped out the exhaust so the cylinder can repeat the process over again with a fresh charge of air and fuel Another 20 to 25 percent of the heat produced during combustion is lost to the cooling system.

As the engine burns fuel. It begins to heat up. Were it not for the cooling system,
the engine ecm would continue to build up heat until it eventually melted and destroyed  the ecm. So heat loss through this path is unavoidable. Another form of loss is overcoming internal friction: piston rings rubbing against the cylinders’,
cam lobes rubbing against their lifters; valves sliding up and down in their valve
guides; the crankshaft turning in its bearings; etc. Yet frictional losses aren’t as great as you might imagine. It’s only about 5 to 8 percent for most engines. Even so, it’s another loss that comes out of the useful work produced by combustion.
A percentage of the engine’s remaining power is also required to drive “parasitic” accessories such as the water pump, alternator, power steering pump, ecm and air conditioning compressor. There are also frictional losses in the engine ecm, transmission, drivetrain, and tires.

Data released from government agencies revealed that from 2003 to 2006, the nation saw a dip in overall vehicular theft – 11 percent, in fact. That still left thousands upon thousands of cars taken in the night (or broad daylight) and resold as legitimate used vehicles, shipped overseas or dismantled for their parts.

According to respected experts on vehicle theft, positive results are being seen from owner-applied theft deterrence and recovery systems. With automotive engineers focusing more on technological advancements, vehicle theft in the United States could continue to be greatly reduced. In the meantime, organizations dedicated to preventing car theft recommend a multi-tiered approach to safeguarding vehicles.

(1) Don’t Make It Easy

Do all you can to make sure those “little things” don’t add up to an easy take. Remember to remove your keys, lock the doors, close the windows, park in well-lit areas and hide all valuables. Thieves are experts. These kinds of mistakes provide them with encouragement to hop in your ride and, well, ride off with it. Plus, most insurers won’t cover the costs of a stolen vehicle if the keys were in or around it.

(2) Use Warning Devices

Any indication your car is protected can act as a deterrent. A thief may be less likely to target your property if you advertise it is protected in some way, either via audio alerts, Vehicle Identification Numbers (VINs) scratched into the windows, or prominent stickers advertising an anti-theft system.

(3) Immobilizing Devices

Immobilization devices prevent the bypassing of the ignition in order to hotwire the vehicle. Examples include smart keys, fuse cut-offs, kill switches, starter/ignition/fuel pump disablers and wireless ignition authentication.

Some of the best immobilization systems will use an electronic code transmitted from a transponder located in the vehicle’s ignition key to allow or disallow the engine management system to start the vehicle. When the correct electronically-coded signal sent by the transponder to a coil located near the ignition is received, the car will start. Such systems can have as many as one trillion fixed codes or a rolling code with encrypted algorithms, making it virtually impossible to crack. As a bonus, some of these systems will also allow the driver to personalize certain features, like seat and mirror position and keyless entry.

(4) Telematics Tracking Devices

Tracking devices are also excellent defenses against car theft. They may, in fact, herald a new era of auto theft protection. Tracking devices use telematics, which can combine a Global Positioning System (GPS) with wireless technology to monitor a vehicle’s location. If thieves realize a particular vehicle can be easily located at any given moment, they may be (should be) far less likely to snatch it. And if they do – well, bad news for them.

Telematics modules may offer more than just vehicular tracking, as well, by virtue of their technological capability. Some in-vehicle systems will also integrate a phone, a global position satellite receiver and digital signal processing to enable communication between a vehicle and a response center. This will provide navigation assistance, remote diagnostics, collision detection and call center notification, hands-free call center communication and remote door lock/unlock.

Other anti-theft devices include steering wheel and ignition locks, audio alerts, keyless vehicle systems, remote keyless activation and ultrasonic interior protection with inclination sensing. The last is, perhaps, one of the more interesting innovations. In an attempt to combat annoying and neighbor-riling false alarms often associated with ignored audio warning systems, certain manufacturers have created theft deterrents designed to sense activity within the vehicle. When interior movement is detected or a change in inclination is sensed, the system will trigger an alarm regardless of the park position. Lifting a vehicle in order to deactivate certain systems is a common trick used by thieves. Inclination sensing combats this technique and ultrasonic protection soothes once-friendly neighbors weary of those midnight false alarms.