COMPONENTS INVOLVED IN ENGINE OPERATON

1.       Frame. The framework of the diesel engine is the load carrying part of the machinery.

2.       Oil drain pan. The oil drain pan is attached to the bottom of the cylinder block and serves to collect and drain oil from the lubricated moving parts of the engine.

3.       Access doors and inspection covers. The cylinder block walls are equipped with access doors or

4.        

5.       handhole covers. With the doors or covers removed, the openings furnish access to cylinder liners, main and connecting rod bearings, injector control shafts, and variousThe doors are usually secured with handwheel or nut operated clamps and are fitted with gaskets to keep dirt and foreign material out of the interior

6.       Cylinder head. The cylinder head seals the end of the cylinder and usually carries the valves. Heads must be strong enough to withstand the maximum pressures developed in the cylinders.

7.       Crankshaft. The crankshaft transforms the reciprocating motion of the pistons into rotary motion of the output shaft. It is one of the largest and most important moving parts of a diesel engine. crankshafts are always heat treated. This is necessary in order to give uniform grain structure, which increases ductility and capacity for resisting shock.

8.       Main bearings. The function of the main bearings is to provide supports in which the crankshaft main bearing journals may revolve

9.       Pistons. The function of a piston is to form a freely movable, gastight closure in the cylinder for the combustion chamber. When combustion occurs, the piston transmits the reciprocal motion or power created to the connecting rod.

10.   Piston rings. Piston rings have the following three primary functions:1. To seal compression in the combustion chamber.2. To transfer heat from the piston to the cylinder wall.3. To distribute and control lubricating oil on the cylinder wall.

11.   Piston pins. Each piston is connected to the connecting rod by a piston pin or wrist pin. This connection is through bored holes in the piston pin hubs at the center of the piston and the integral hub of the connecting rod.

12.   Connecting rods. Just as its name implies, the connecting rod connects the piston with the crankshaft. It performs the work of converting the reciprocating, or back-and-forth, motion of the piston into the rotary, or circular, motion of the crankshaft.

13.   Connecting rod bearings. The purpose of these bearings is to form a low-friction, well-lubricated surface between the connecting rod and the crankshaft in which the crankpin journals can revolve freely.

14.   Valve. Control of the flow of fuel, inlet air, starting air, and exhaust gases in a diesel cylinder is accomplished by means of various types of valves.

15.   Exhaust valves. Exhaust valves are used to allow the exhaust gases of combustion to escape from the cylinders.

16.   Fuel injection valves. Fuel injection valves are used to inject the fuel spray into the cylinder at the proper time with the correct degree of atomization. In addition, some injection valves also measure the amount of fuel injected

17.   Air starting valves. Air starting valves are used to control the flow of starting air during air starting of an engine.

18.   Cylinder test valves. Each cylinder is provided with a test valve which is used to vent the cylinder before starting. This valve is also used to relieve the cylinder of compression when turning over the engine by hand

19.   Cylinder relief valves. A cylinder relief, or safety, valve is located on each cylinder of all submarine type engines. The function of this valve is to open and relieve the cylinder when pressure inside the cylinder becomes excessive.

20.   Camshafts. The purpose of the camshafts in submarine diesel engines is to actuate exhaust valves, fuel injectors, fuel injection pumps, and air starting valves according to the proper timing sequence of that particular engine.

VIDEO EXPLANATION ABOUT ENGINE OPERATION

TOYOTA VVTI  SYSTEM EXPLAINATION

Any mechanic or automotive enthusiast can tell you that an engine is essentially a large air pump. The more an engine can suck in air to mix with fuel, the more it can create power through combustion. Thus, the more efficiently an engine removes exhaust gases from the cylinders, the better it can manage that power. The key to a strong, healthy engine is adequate air from one end to another.

Air flow is affected by many different components in the motor, but the valves in the cylinder head are what directly control the amount of air entering a cylinder, and the volume of exhaust gases leaving it. The intake valves open up just prior to combustion in order to allow air to flow in and mix with fuel, and the exhaust valves open after the ignition of this mixture in order to suck out the resulting gases. The timing of the valves is controlled by a rotating shaft called the camshaft. The camshaft has lobes which push up on the valves in order to open them and drop them back closed again.

How long these valves remain open, and at what point in the combustion cycle, can have a big impact on the drivability and power generated by an engine. For instance, if you want to have a really fast car, like a race car, you'll want the engine to produce a lot of power at high RPMs. You can adjust the camshaft to perform well at higher RPMs. This will result in poor performance at low RPMs, but that's OK with a race car. Conversely, if you want a lot of low-end torque - which is great for towing - you need to adjust the camshaft to perform well at low RPMs. This, of course, will hurt high RPM performance.

Unfortunately, street vehicles are a compromise between reliability, fuel efficiency and power. While race vehicles have engines with camshaft designs that generate large amounts of power while being used only at specific, high revolutions, your daily driver sees a wide range of RPMs that make a broader power band necessary. While it is ok for a race car to have a lumpy idle that barely runs below 1000 rpm, it would do you no good if your street car stalled out at every stoplight. Regular vehicles usually have to make do with a camshaft that provides a good amount of power in the most often used range of engine RPMs, but runs out of steam at high speeds.

The problem with compromise camshafts is that they're not all that efficient. Since everyday vehicles operate at a variety of different RPMs, the engine needs to be just as capable of accelerating from a dead stop as it is of zooming along at highway speeds, and everything in between. The result is that your engine often ends up burning too much fuel while underperforming.

Automakers have addressed this concern with something called "variable valve timing" (VVT). The Toyota Tundra's i-Force 5.7L V8, Toyota's newest VVT-i engine, has the ability to vary the timing of the valves in relation to engine speed. It does this by using engine oil pressure to move the camshaft slightly, so that more aggressive lobe designs are used when the engine is running at a higher rpm. By doing this, the i-Force V8 is able to run a camshaft profile that provides good fuel efficiency in every day driving, but is still able to churn out gobs of power when the pedal is pressed to the floor.

The dual VVT-i in the Tundra takes things a step further by allowing the exhaust and intake valves to open at the same time at very high RPMs in order to scavenge the airflow as much as possible. This all adds up to a V8 engine that produces 381 horsepower at 5600 rpm while still generating 401 lb-ft of torque at as low as 3600 rpm. Not only that, but in the 2 wheel drive models, the Tundra gets a respectable 20 miles per gallon on the highway. Perhaps most importantly, Toyota's variable valve timing system lets you have killer horsepower without getting killed at the gas pump

TYPE OF ENGINE USED IN TOYOTA CARS

      I.            VVT-i

Cutaway view of Variable ValveTiming with ignition engine

VVT-i, or Variable Valve Timing with intelligence, is an automobile variable valve timing technology developed by Toyota. The Toyota VVT-i system replaces the Toyota VVT offered starting in 1991 on the 5-valve per cylinder 4A-GE engine. The VVT system is a 2-stage hydraulically controlled cam phasing system.

VVT-i, introduced in 1996, varies the timing of the intake valves by adjusting the relationship between the camshaft drive (belt, scissor-gear or chain) and intake camshaft. Engine oil pressure is applied to an actuator to adjust the camshaft position. Adjustments in the overlap time between the exhaust valve closing and intake valve opening result in improved engine efficiency.^[1] Variants of the system, including VVTL-i, Dual VVT-i, VVT-iE, and Valvematic, have followed.

II.            VVTL-i

The cutaway of  VVTL-i engine

VVTL-i (Variable Valve Timing and Lift intelligent system) (also sometimes denoted as VVT-iL or Variable Valve Timing and Intelligence with Lift) is an enhanced version of VVT-i that can alter valve lift (and duration) as well as valve timing. In the case of the 16 valve 2ZZ-GE, the engine head resembles a typical DOHC design, featuring separate cams for intake and exhaust and featuring two intake and two exhaust valves (four total) per cylinder. Unlike a conventional design, each camshaft has two lobes per cylinder, one optimized for lower rpm operation and one optimized for high rpm operation, with higher lift and longer duration. Each valve pair is controlled by one rocker arm, which is operated by the camshaft. Each rocker arm has a slipper follower mounted to the rocker arm with a spring, allowing the slipper follower to freely move up and down with the high lobe without affecting the rocker arm. When the engine is operating below 6000-7000 rpm (dependent on year, car, and ECU installed), the lower lobe is operating the rocker arm and thus the valves, and the slipper-follower is freewheeling next to the rocker arm. When the engine is operating above the lift engagement point, the ECU activates an oil pressure switch which pushes a sliding pin under the slipper follower on each rocker arm. The rocker arm is now locked into slipper-follower's movements and thus follows the movement of the high rpm cam lobe, and will operate with the high rpm cam profile until the pin is disengaged by the ECU. The lift system is similar in principle to Honda VTEC operation.

The system was first used in 2000 Toyota Celica with 2ZZ-GE. Toyota has now ceased production of its VVTL-i engines for most markets, because the engine does not meet Euro IV specifications for emissions. As a result, this engine has been discontinued on some Toyota models, including that of the Corolla T-Sport (Europe), Corolla Sportivo (Australia), Celica, Corolla XRS, Toyota Matrix XRS, and the Pontiac Vibe GT, all of which had the 2ZZ-GE engine fitted. The Lotus Elise continues to offer the 2ZZ-GE and the 1ZZ-FE engine, while the Exige offers the engine with a supercharger. The Toyota Yaris uses VVT-i on its gasoline engines.

III.            Dual VVT-i

The cutaway of Dual VVT-i engine

The Dual VVT-i system adjusts timing on both intake and exhaust camshafts. It was first introduced in 1998 on the RS200 Altezza's 3S-GE engine.

Dual VVT-i is also found in Toyota's new generation V6 engine, the 3.5-liter 2GR-FE first appearing on the 2005 Avalon. This engine can now be found on numerous Toyota and Lexus models. By adjusting the valve timing, engine start and stop occurs almost unnoticeably at minimum compression. Fast heating of the catalytic converter to its light-off temperature is possible, thereby reducing hydrocarbon emissions considerably.

Most Toyota engines including the LR engines (V10, used in the Lexus LFA), UR engines (V8), GR engines (V6), AR engines (Large I4), and ZR engines (Small I4) now use this technology.

HISTORY OF ENGINE VVT-i

VVT-i, or Variable Valve Timing with intelligence, is an automobile variable valve timing technology developed by Toyota. The Toyota VVT-i system replaces the Toyota VVT offered starting in 1991 on the 5-valve per cylinder 4A-GE engine. The VVT system is a 2-stage hydraulically controlled cam phasing system.

Conclusion:

There is no overlooking the BMW M6’s hefty price. However, most M6 owners are extremely satisfied with their purchase. The car’s high-tech features and stunning design make it a dream vehicle. Every driver will get addicted to the M6’s high-revving engine.

Introduction to Engine Operation : (Saturn I4 Engine)

Introduction to Engine Operation : (Saturn I4 Engine)

i) Definition of the Systems
The powerplant used in Saturn S-series automobiles was a straight-4 aluminum piston engine produced by Saturn. The engine was only used in the Saturn S-series line of vehicles (SL, SC, SW) from 1991 through 2002. It was available in chain-driven SOHC or DOHC variants.
This was an innovative engine for the time using the lost foam casting process for the engine block and cylinder head. Saturn was one of the first to use this casting process in a full-scale high-production environment. Both engine types used the same engine block.

Saturn I4 Engine - technical specs

Overview
Manufacturer	Saturn Corporation
Also called	Single Cam Twin Cam
Combustion chamber
Displacement	1,901 cc (116.0 cu in)
Cylinder bore	82.0 mm (3.23 in)
Piston stroke	90.0 mm (3.54 in)
Cylinder block alloy	Aluminum
Cylinder head alloy	Aluminum
Valvetrain	SOHC DOHC
Compression ratio	SOHC: 9.3:1 DOHC: 9.5:1
Combustion
Fuel system	Throttle-body fuel injection Sequential multiport fuel injection
Fuel type	Gasoline
Oil system	Wet sump
Cooling system	Watercooled
Output
Power output	LK0: 85 hp (63 kW) L24: 100 hp (75 kW) LL0: 124 hp (92 kW)
Specific power	LK0: 44.73 hp/L L24: 52.63 hp/L LL0: 65.26 hp/L
Torque output	LK0: 107 lb·ft (145 N·m) L24: 115 lb·ft (156 N·m) LL0: 122 lb·ft (165 N·m)
Dimensions
Dry weight	SOHC: 196.74 lb (89.24 kg) DOHC: 220.22 lb (99.89 kg)
Chronology
Successor	Ecotec engine (De facto)

the explanation of I4 engine

the explanation of balancing shafts in I4 engine

Inline-four engine

• 4 cylinders are less costly than 6 or 8 when you take into account the additional pistons, fuel injectors, spark plugs, and valvetrain components.

• An inline engine is less costly to produce than a V or boxer because the V and boxer will both have multiple heads and sets of valvetrain components and the blocks will be more complex.

• Reducing the number of cylinders for a given displacement (maximizing piston/cylinder size) will reduce the surface area available for heat transfer (loss) and will reduce the length sealed by piston rings. Both of these effects make a 4 cylinder engine more efficient than a 6 or 8 cylinder engine of equivalent displacement.

• 4 cylinder engines can be very easy to service as the engine can be accessed from the top. Often boxer engines and V engines are more difficult to service, especially in tight engine bays, because the main components aren't pointing "straight up."

The inline 4 cylinder engine is in primary balance but not secondary balance, but the balance issues that this configuration has are not insurmountable and dealing with them does not outweigh the other benefits this configuration provides. As far as balance, one of the best engines for balance is an inline 6 (which is in perfect primary and secondary balance), but inline 6 engines are only used in limited applications because they're very long and difficult to fit in a short engine bay. Many inline 4 cylinders are transversely mounted for front-wheel-drive cars. Longer engines (such as an inline 6) are much easier to mount front-to-back and as such are more popular in rear-wheel-drive applications such as certain sports cars and trucks.

While additional cylinders have often been the answer for more power in the past, now manufacturers are often turbocharging their engines to increase the power output of the engines in an effort to get more power from smaller engines and raise fuel economy, thus reducing the need to move up to a V6 engine.

Engineering in general (especially automotive) is often about deciding between different tradeoffs. While the inline 4 cylinder engine isn't perfect it has a number of attributes which make it highly attractive and aren't outweighed by its drawbacks.