Whats a Petcock

Is a regulator consisting of a small cock or faucet or valve for letting out air or releasing compression or draining. Although petcocks are used in a wide variety of applications, the following passage will describe one of the most common applications of the petcock which is the control of gasoline on a motorcycle engine.

Most motorcycles have a fuel petcock valve mounted on or nearby the gas tank to control the supply of gasoline. The petcock typically has three positions: ON, OFF, and RESERVE. The reserve position accesses the bottom portion of the gas tank. The reserve position functionality of the petcock is especially useful on motorcycles because they often don't possess a fuel gauge.

When operating a motorcycle the fuel management process often proceeds as follows: Especially when regarding vintage motorcycles the petcock is set to the off position when the motorcycle is not being operated. This is to eliminate fuel overflow and leakage via the carburetor(s). Before starting the engine the petcock is turned to the ON position in order to provide gasoline to the fuel delivery system.

While operating the engine there will reach a point at which fuel consumption causes the level of gasoline in the gas tank to fall below that which can be accessed by the petcock in the ON position. At that time continued operation of the engine can be maintained. This operation is achieved by accessing the remaining fuel in the gas tank via rotating the valve in the petcock to the RESERVE position.

TVS SUPERCHARGER

Eaton’s new Twin Vortices Series (TVS) is a roots-type supercharger for a variety of engine applications that delivers more power and better fuel economy in a smaller package, for uncompromising, high-performance driving.

The TVS supercharger’s patented design features four-lobe rotors and high-flow inlet and outlet ports that greatly enhance thermal efficiency, deliver higher volumetric capacity, and enable higher operating speeds. The TVS supercharger is capable of running with a high thermal efficiency (up to 76 percent) across a very wide operating range.

The improvements incorporated into the TVS design allow for the use of a smaller supercharger, reducing the package size and weight of the system. The sizes range from 350cc to 2300cc per revolution, and cover engines from 0.6 liter up to large displacement V-engines. All TVS superchargers have a 2.4 pressure ratio capability and a thermal efficiency that exceeds 70 percent, which enables more compact packaging and greater output.

The twin four-lobe rotors feature 160-degree twists. The higher helix angle of the rotors coupled with a redesigned inlet and outlet ports, improves the TVS’s air-handling characteristics without increasing the overall size of the unit. The TVS improved noise and vibration characteristics eliminate additional noise-reduction treatments, complexity and system cost.

The TVS sets a new standard of boosting device performance and reaffirms Eaton’s leadership in the performance automotive market!

Roots type supercharger

The Roots type supercharger or Roots blower is a positive displacement type device which operates by pulling air through a pair of meshing lobes not unlike a set of stretched gears. Air is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. The supercharger is typically driven directly from the engine's crankshaft via a belt.

It is named for the brothers Philander and Francis Roots, who first patented the basic design in 1860 as an air pump for use in blast furnaces and other industrial applications. In 1900, Gottlieb Daimler included a Roots-style supercharger in a patented engine design, making the Roots-type supercharger the oldest of the various designs now available.

Out of the three basic supercharger types the Roots has historically been considered the least efficient. However, recent engineering developments by Eaton Corporation has resulted in a new Roots-type supercharger which yields a pump that is more efficient than all previous models. In addition, the Roots-type supercharger is simple and widely used and thus is invariably the most cost efficient. It is also more effective than alternative superchargers at developing compression at low engine rpms, making it a popular choice for passenger automobile applications. Peak torque can be achieved by about 2000 rpm.

All supercharger types benefit from the use of an intercooler to remove heat produced during compression. With a Roots-type supercharger, a thin heat exchanger is adapted to fit in-between the blower and the engine. Water is circulated through it to a second unit placed near the front of the vehicle where a fan and the ambient air-stream can dissipate the collected heat.

The Roots design is commonly used on two-stroke diesel engines, which require some form of forced induction as there is no intake stroke. In this application, the blower does not often provide significant compression and these engines are considered naturally aspirated; turbochargers are generally used when significant "boost" is needed. The Rootes Co. two-stroke diesel engine, used in Commer and Karrier vehicles, had a Roots-type blower but the two names are not connected.

The superchargers used on top fuel engines, funny cars, and other dragsters, as well as hot rods, are in fact derivatives of General Motors superchargers for their diesel engines, which were adapted for automotive use in the early days of the sport. The model name of these superchargers delineates their size; i.e. the once commonly used "6-71" and "4-71" blowers were designed for General Motors diesels having six cylinders of 71 cubic inches each, and four cylinders of 71 cubic inches each, respectively. Current competition dragsters use blowers of 14-71 design.

How Extend The Life Of Your Car Battery

There are several strategies you can use to extend the life of your car battery and avoid a dead battery crisis. Regular maintenance of your automotive battery is a must, especially in extreme weather conditions. Remember over heating is bad. Check the electrolyte level in the battery. One of the easiest cleaning tips, is to make sure the terminals are clean. You can buy an cheap terminal brush and scrub off any corrosion on the battery terminals and cables. Sometimes a dead battery is nothing more than corroded terminals. Once they are clean, your car will crank right up. Car batteries also need to be recharged after deep cycle discharges and jump starts.
If you run an auto shop or other mechanical service, you will need a car battery charger to recharge your batteries. The time required to charge a car battery back to a full charge depends on the number of ampere hours (AH) depleted. Ampere hours are calculated by multiplying the number of hours times the number of Amps that the battery supplied to the load. For example, if a load was connected to a battery that used 7 Amps for 5 hours, the car battery supplied 35 Ahs. The recharge time would then be calculated by dividing 35 Ahs by the amperage charge rate of the charger. Once you are armed with this information you can make sure your batteries are fully charged and remain healthy.

If you are storing you batteries for a long period of time, such as a ski boat in winter. A trickle charger is highly recommended. These will slowly charge your battery and make sure it remains fully charged through the winter months. It is better to let the battery stay fully charged then try to recharge it in the spring. Fully discharging the battery will reduce its overall life.
By taking these simple suggestions, you can extend the life of your battery and hopefully avoid getting caught with a car that won’t start.

1992-96 2.2L 4 cylinder excluding VTEC engine Honda Prelude S model Radiator

This replacement radiator is just what you need to get your vehicle in working order again. All of our radiators feature these great qualities:

* Direct replacement that is built to strict quality control specifications
* Engineered for optimum heat-transfer performance and fit
* 100% tested each and every time
* Plastic tanks with metal core
* Guaranteed fit to standard and automatic transmission models

Specifications

Core Size: 13 3/4" x 26 1/4" x 1 1/4"
Top header: 2" x 27"
Bottom header: 2" x 27"
Inlet kneck diameter: 1 1/4"
Outlet kneck diameter: 1 1/4"
Rows: 2
Distance between transmission oil cooler fittings: 12 3/4"

This part is built to strict quality control standards. Makes a great replacement and has substantial cost savings over a dealer unit.

A note on Radiator and Heater Core Shipping: Due to the nature and size, a radiator may incur small dents and scratches on the cooling fins, tubes and/or tanks from handling and load shifting during shipping. Bent tubes can be easily repaired and dents and scratches do not affect the fit or function of the part. Neither our 60 Day satisfaction guarantee, nor the manufacturer’s warranty, cover these insignificant damages.
This Part Fits The Following Model Years:

* 1992 (92) Honda Prelude
* 1993 (93) Honda Prelude
* 1994 (94) Honda Prelude
* 1995 (95) Honda Prelude
* 1996 (96) Honda Prelude
engines cars hybrid engine reviews

Zenith Carburetters

Zenith Carburetters was a British company making carburetters. In 1955 they joined with their major pre-war rival Solex Carburetters and over time the Zenith brand name fell into disuse. The rights to the Zenith designs was owned by Solex UK.

The big products of Zenith were the Zenith-Stromberg carburettors used in MGs, 1967-1975 Jaguar E-types, Saab 90s and early 99s and 900s, 1969-1972 Volvo 140s and 164s, and some 1960s and 1970s Triumphs, for instance the Triumph Spitfire used Zenith IV carburettors in the North American market. In Australia the CD-150 and CDS-175 models were fitted to the hi performance triple carburettored Holden Torana GTR-XU1.

The Stromberg carburettor features a variable venturi controlled by a piston. This piston has a long, tapered, conical metering rod that fits inside an orifice which admits fuel into the airstream passing through the carburettor. Since the needle is tapered, as it rises and falls it opens and closes the opening in the jet, regulating the passage of fuel, so the movement of the piston controls the amount of fuel delivered, depending on engine demand.

The flow of air through the venturi creates a reduced static pressure in the venturi. This pressure drop is communicated to the upper side of the piston via an air passage. The underside of the piston is in communication with atmospheric pressure. The difference in pressure between the two sides of the piston creates a force tending to lift the piston. Counteracting this force is the force of the weight of the piston and the force of a compression spring which is compressed by the piston rising; because the spring is operating over a very small part of its possible range of extension, the spring force approximates to a constant force. Under steady state conditions the upwards and downwards forces on the piston are equal and opposite, and the piston does not move.

If the airflow into the engine is increased - by opening the throttle plate, or by allowing the engine revolutions to rise with the throttle plate at a constant setting - the pressure drop in the venturi increases, the pressure above the piston falls, and the piston is sucked upwards, increasing the size of the venturi, until the pressure drop in the venturi returns to its nominal level. Similarly if the airflow into the engine is reduced, the piston will fall. The result is that the pressure drop in the venturi remains the same regardless of the speed of the airflow - hence the name "constant depression" for carburettors operating on this principle - but the piston rises and falls according to the speed of the airflow.

Since the position of the piston controls the position of the needle in the jet, and thus the open area of the jet, while the depression in the venturi sucking fuel out of the jet remains constant, the rate of fuel delivery is always a definite function of the rate of air delivery. The precise nature of the function is determined by the tapered profile of the needle. With appropriate selection of the needle, the fuel delivery can be matched much more closely to the demands of the engine than is possible with the more common fixed-venturi carburettor, an inherently inaccurate device whose design must incorporate many complex fudges to obtain usable accuracy of fuelling. The well-controlled conditions under which the jet is operating also make it possible to obtain good and consistent atomisation of the fuel under all operating conditions.

This self-adjusting nature makes the selection of the maximum venturi diameter (colloquially, but inaccurately, referred to as "choke size") much less critical than with a fixed-venturi carburettor.

To prevent erratic and sudden movements of the piston it is damped by light oil in a dashpot (under the white plastic cover in the picture) which requires periodic topping up.

SU carburetor

SU carburettors (named for Skinners Union, the company that produced them) were a brand of sidedraft carburettor widely used in British (Austin, Morris, Triumph, MG) and Swedish (Volvo, Saab 99) automobiles for much of the twentieth century. Originally designed and patented by George Herbert Skinner in 1905, they remained in production through to the 1980s by which time they had become part of the BMC/British Leyland Group. Hitachi also built carburettors based on the SU design which were used on the Datsun 240Z and other Datsun Cars. While these look the same, they are different enough that needles (see below) are the only part that fits both.

SU carburettors featured a variable venturi controlled by a piston. This piston has a tapered, conical metering rod (usually referred to as a "needle") that fits inside an orifice ("jet") which admits fuel into the airstream passing through the carburettor. Since the needle is tapered, as it rises and falls it opens and closes the opening in the jet, regulating the passage of fuel, so the movement of the piston controls the amount of fuel delivered, depending on engine demand.

The flow of air through the venturi creates a reduced static pressure in the venturi. This pressure drop is communicated to the upper side of the piston via an air passage. The underside of the piston is open to atmospheric pressure. The difference in pressure between the two sides of the piston tends to lift the piston. Opposing this are the weight of the piston and the force of a spring that is compressed by the piston rising. Because the spring is operating over a very small part of its possible range of extension, its force is approximately constant. Under steady state conditions the upwards and downwards forces on the piston are equal and opposite, and the piston does not move.

If the airflow into the engine is increased - by opening the throttle plate (usually referred to as the "butterfly"), or by allowing the engine revs to rise with the throttle plate at a constant setting - the pressure drop in the venturi increases, the pressure above the piston falls, and the piston is sucked upwards, increasing the size of the venturi, until the pressure drop in the venturi returns to its nominal level. Similarly if the airflow into the engine is reduced, the piston will fall. The result is that the pressure drop in the venturi remains the same regardless of the speed of the airflow - hence the name "constant depression" for carburettors operating on this principle - but the piston rises and falls according to the speed of the airflow.

Since the position of the piston controls the position of the needle in the jet and thus the open area of the jet, while the depression in the venturi sucking fuel out of the jet remains constant, the rate of fuel delivery is always a definite function of the rate of air delivery. The precise nature of the function is determined by the profile of the needle. With appropriate selection of the needle, the fuel delivery can be matched much more closely to the demands of the engine than is possible with the more common fixed-venturi carburettor, an inherently inaccurate device whose design must incorporate many complex fudges to obtain usable accuracy of fuelling. The well-controlled conditions under which the jet is operating also make it possible to obtain good and consistent atomisation of the fuel under all operating conditions.

This self-adjusting nature makes the selection of the maximum venturi diameter (colloquially, but inaccurately, referred to as "choke size") much less critical than with a fixed-venturi carburettor. A two-inch SU carburettor is a useful device to have in the workshop when experimenting with engines, as it is possible to bolt it onto more or less any engine and the engine, if in good order, will burst into life without the need for complex carburettor adjustments to get it to start.

To prevent erratic and sudden movements of the piston it is damped by light oil in a dashpot, which requires periodic topping up. The dampening is asymmetrical; it heavily resists upwards movement of the piston. This serves as the equivalent of an "accelerator pump" on traditional carburettors by temporarily increasing the speed of air through the venturi, thus increasing the richness of the mixture.

The beauty of the SU lies in its simplicity and lack of multiple jets and ease of adjustment. Adjustment is accomplished by altering the starting position of the jet relative to the needle on a fine screw. At first sight, the principle appears to bear a similarity to that used on many motorcycles where the main needle position is raised and lowered by a direct connection to the throttle cable rather than indirectly by the depression in the venturi. However, this apparent similarity is misleading. The piston in a motorcycle-type carburettor is controlled by the demands of the rider rather than the demands of the engine, so the metering of the fuel is inaccurate unless the motorcycle is travelling at a constant speed at a constant throttle setting - conditions which are rarely encountered except on motorways. This inaccuracy results in the wasting of fuel, particularly as the carburettor must be set slightly rich to avoid damaging leanness under transient conditions. For this reason Japanese motorcycle manufacturers ceased to fit slide carbs and substituted constant-depression carbs which are essentially miniature Japanese SUs. It is also possible - indeed, easy - to retro-fit an SU carburettor to a bike that was originally manufactured with a slide carburettor, and thereby obtain improved fuel economy and more tractable low-speed behaviour.

Weber carburetor

Weber carburetors were originally produced in Italy by Edoardo Weber as part of a conversion kit for 1920s Fiats. Weber pioneered the use of two stage twin barrel carburetors, with two venturis of different sizes, the smaller one for low speed running and the larger one optimised for high speed use.

In the 1930s Weber began producing twin barrel carburetors for motor racing where two barrels of the same size were used. These were arranged so that each cylinder of the engine has its own carburetor barrel. These carburetors found use in Maserati and Alfa Romeo racing cars. Twin updraught Webers fed superchargers on the 1938 Alfa Romeo 8C competition vehicles.

In time, Weber carburetors were fitted to standard production cars and factory racing applications on automotive marques such as Abarth, Alfa Romeo, Aston Martin, BMW, Ferrari, Fiat, Ford, Lamborghini, Lancia, Lotus, Maserati, Porsche, Triumph and Volkswagen.

In the United States Weber Carburetors are sold for both street and off road use. They are sold in what is referred to as a Weber Conversion kit. A Weber conversion kit is a complete package of Weber Carburetor, intake manifold or manifold adapter, throttle linkage, air filter and all of the necessary hardware needed to install the Weber on a vehicle.

In modern times, fuel injection has replaced carburetors in both production cars and most modern motor racing, although Weber carburetors are still used extensively in classic and historic racing. They are also supplied as high quality replacements for problematic OEM carburetors. Weber fuel system components are distributed by Magneti-Marelli and Webcon UK Ltd.

Gudgeon pin

The gudgeon pin is that which connects the piston to the connecting rod and provides a bearing for the connecting rod to pivot as it moves. In very early engine designs (including those driven by steam and also many very large stationary or marine engines, the gudgeon pin is located in a sliding crosshead that connects to the piston via a rod.

The gudgeon pin is typically a forged short hollow rod made of a steel alloy of high strength and hardness that may be physically separated from both the connecting rod and piston or crosshead. The design of the gudgeon pin, especially in the case of small, high-revving automotive engines is challenging. The gudgeon pin has to operate under some of the highest temperatures experienced in the engine, with difficulties in lubrication due to its location, while remaining small and light so as to fit into the piston diameter and not unduly add to the reciprocating mass. The requirements for lightness and compactness demand a small diameter rod that is subject to heavy shear and bending loads, with some of the highest pressure loadings of any bearing in the whole engine. To overcome these problems, the materials used to make the gudgeon pin and the way it is manufactured are amongst the most highly-engineered of any mechanical component found in internal combustion engines.


Design Options

Gudgeon pins use two broad design configurations: semi-floating or fully-floating. In the semi-floating configuration, the pin is usually fixed relative to the piston by an interference fit with the journal in the piston. The connecting rod small end bearing thus acts as the bearing alone. In this configuration, only the small end bearing requires a bearing surface, if any. If needed, this is provided by either electroplating the small end bearing journal with a suitable metal, or more usually by inserting a bearing sleeve into the eye of the small end, which has an interference fit with the aperture of the small end. During overhaul, it is usually possible to replace this bearing sleeve if it is badly worn. The reverse configuration that is occasionally implemented is an interference fit with the small end eye instead, with the gudgeon pin journals in the piston functioning as bearings. This arrangement is usually more difficult to manufacture and service because two bearing surfaces or inserted sleeves complicate the design. In addition, the pin must be precisely set so that the small end eye is central. Because of thermal expansion considerations, this arrangement is more usual for single-cylinder engines as opposed to multiple cylinder engines with long cylinder blocks and crankcases.

In the fully-floating configuration, a bearing surface is created both between the small end eye and gudgeon pin and the journal in the piston. No interference fit is used in any instance and the pin 'floats' entirely on bearing surfaces. The average rubbing speed of each of the three bearings is halved and the load is shared across a bearing that is usually about three times the length of the semi-floating design with an interference fit with the piston.

Hydramatic Design

The Hydramatic used a two-element fluid coupling (not a torque converter, which has at least three elements, the pump, turbine and stator) and three planetary gearsets, providing four forward speeds plus reverse. Standard ratios for the original Hydra-Matic were 3.82:1, 2.63:1, 1.45:1 and 1.00:1 in automotive applications, and 4.08:1, 2.63:1, 1.55:1 and 1.00:1 in light truck and other commercial applications. The Jetaway Hydramatic used 3.96:1, 2.55:1, 1.55:1, and 1.00:1.

A unique feature of the Hydramatic design was the manner in which the fluid coupling was interposed in the power flow. In modern automatics, all engine power passes through the torque converter and then on to the gear train. Unless the converter includes a clutch to lock the turbine to the pump, some slippage will always occur, which can have a significant negative effect on efficiency and fuel economy. This was not the case with the Hydramatic.

In first gear, power flow was through the forward planetary gear assembly (either 1.45:1 or 1.55:1 reduction, depending on the model), then the fluid coupling, followed by the rear gear assembly (2.63:1 reduction) and through the reverse gear assembly (normally locked) to the output shaft. That is, the input torus of the fluid coupling ran at a lower speed than the engine, due to the reduction of the forward gear assembly. This produced an exceptionally smooth startup because of the relatively large amount of slippage initially produced in the fluid coupling. This slippage quickly diminished as engine RPM increased.

When the transmission upshifted to second gear, the forward gear assembly locked and the input torus now ran at engine speed. This had the desirable effect of "tightening" the coupling and reducing slippage, but unfortunately also produced a somewhat abrupt shift. It wasn't at all uncommon for the vehicle to lurch forward during the 1-2 shift, especially when the throttle was wide open.

Upon shifting to third, the forward gear assembly went back into reduction and the rear gear assembly locked. Due to the manner in which the rear gear assembly was arranged, the coupling went from handling 100 percent of the engine torque to about 40 percent, with the balance being handled solely by the gear train. This greatly reduced slippage, which fact was audible by the substantial reduction that occurred in engine RPM when the shift occurred.

The shift from third to fourth gear locked the forward gear assembly, producing 1.00:1 transmission. The fluid coupling now only handled about 25 percent of the engine torque, reducing slippage to a negligible amount. The result was a remarkably efficient level of power transfer at highway speeds, something that torque converter equipped automatics could not achieve without the benefit of a converter clutch.

Many Hydramatics did not execute the 2-3 shift very well, as the shift involved the simultaneous operation of two bands and two clutches. Accurate coordination of these components was difficult to achieve, even in new transmissions. As the transmission's seals and other elastomers aged, the hydraulic control characteristics changed and the 2-3 shift would either cause a momentary flare (runup in engine speed) or tie-up (a short period where the transmission is actually in two gears at the same time), the latter often contributing to failure of the front band.

From 1939 through 1950, the reverse anchor was used to lock the reverse unit ring gear from turning by engaging external teeth machined into that ring gear. From 1951 on, a cone clutch did the same thing when oil pressure was up, and a spring loaded parking pawl was allowed to lock the same ring gear in the absence of oil pressure. This worked better as the anchor would not grind on the external teeth if that ring gear were turning (that is, unless the engine stalled as reverse was engaged). Reverse was obtained by applying torque from the front unit (band on, in reduction) through the fluid coupling to the rear unit sun gear. The planet carrier of this gearset was splined to the planet carrier of the reverse unit. The rear unit ring gear hub had a small gear machined on its end which served as the reverse unit sun gear. Because the rear unit band was not applied for reverse, the rear unit and reverse unit compounded causing the combined planet carriers to rotate opposit to the input torque and at a further reduced speed (similar to the Model T Ford reverse). The output shaft was machined onto the rear unit and reverse unit planet carriers.

Shutting off the engine caused the transmission oil pressure to fall off. If the selector lever was in reverse or moved to reverse after the engine stopped, two mechanical parts combined to provide a parking brake. The reverse unit ring gear was held stationary by the reverse anchor. The drive shaft could still turn causing the reverse unit sungear and attached rear unit ring gear to rotate at a very high speed, were it not for the fact that the rear unit ring gear band was now applied by a heavy spring. Usually, bands are applied by a servo and released by spring pressure, but in this case, the band was held off by the servo and applied by spring pressure (actually, when the engine was running, the band was applied by a combination of spring pressure assisted by oil pressure). With the engine off, this brake band acting on the rear unit ring gear had a tremendous mechanical advantage. Since the rear unit ring gear with its attached reverse unit sun gear and the reverse unit ring gear were both locked to the transmission case, the planet carriers and driveshaft could not turn. As such, it provided and effective driveshaft mounted parking brake to be used alone or supplementing the hand brake.

Piston Top dead centre

Top dead centre (TDC) in a piston engine, is the position of a piston in which it is furthest from the crankshaft. The position closest to the crankshaft is known as bottom dead centre (BDC).

Top dead centre is the datum point from which engine timing measurements are made. For example, ignition system timing is normally specified as degrees before top dead centre (BTDC) although a very few small and fast-burning engines, require a spark just after top dead centre (ATDC), such as the Nissan MA engine with hemispherical combustion chambers, or hydrogen engines.

Top dead centre for cylinder one is often marked on the crankshaft pulley, the flywheel or dynamic balancer or both, with adjacent timing marks showing the recommended ignition timing settings as decided during engine development. These timing marks can be used to set the ignition timing either statically by hand or dynamically using a timing light, by rotating the distributor in its seat.

In a multi-cylinder engine, pistons may reach top dead centre simultaneously or at different times depending on the engine configuration. For example:

* In the V-twin configuration, the two pistons reach TDC at different times, equal to the angular displacement between the cylinders.

* In the boxer twin configuration, two opposing pistons reach TDC simultaneously, which is also called 0° displacement.

* In the straight-4 configuration, the two end pistons (pistons 1 and 4) reach TDC simultaneously, as do the two centre pistons (pistons 2 and 3), but these two pairs reach TDC with an angular displacement of 180°. Similar patterns are found in almost all straight engines with even numbers of cylinders, with the two end pistons and two middle pistons moving together (not necessarily 180° out of phase however) and the intermediate pistons moving in pairs in mirror-image around the centre of the engine.

* In the flatplane V8 and many larger V engines, the piston motion within each bank is similar to that of a straight engine, however in the crossplane V8 and all V10 engines the motion is far more complex.

The concept of top dead centre is also extended to pistonless rotary engines, and means the point in the cycle in which the volume of a combustion chamber is smallest. This typically occurs several times per rotor revolution; In the Wankel engine for example it occurs three times for every one revolution of the rotor.

This term is also used in the realm of production equipment. A mechanical punch press employs a crankshaft similar to that found in an engine. In the punch press the crankshaft drives a ram which when it is farthest away from the platen of the press is considered to be in the position of top dead center.

Diesel engine Glow Plug

Glow plugs are used to heat the combustion chambers of some diesel engines in cold conditions to help ignition at coldstart. In the tip of the glow plug is a coil of a resistive wire or a filament which heats up when electricity is connected.

Glow plugs are required because diesel engines produce the heat needed to ignite their fuel by the compression of air in the cylinder and combustion chamber. Gasoline engines use an electric spark plug. In cold weather, and when the engine block, engine oil and cooling water are cold, the heat generated during the first revolutions of the engine is conducted away by the cold surroundings, preventing ignition. The glow plugs are switched on prior to turning over the engine to provide heat to the combustion chamber, and remain on as the engine is turned over to ignite the first charges of fuel. Once the engine is running, the glow plugs are no longer needed, although some engines run the glow plugs for between 5 and 10 seconds after starting to ensure smooth and efficient running and sometimes to keep the engine within emissions regulations (combustion efficiency is greatly reduced when the engine is very cold). During this period, the power fed to the glow plugs is greatly reduced to prevent them burning out by overheating.

-injection diesel engines are less thermally efficient due to the greater surface area of their combustion chambers and so suffer more from cold-start problems. They require longer pre-heating times than direct-injection engines, which often do not need glow plugs at all in temperate or hot climates even for a cold start.

In a typical diesel engine, the glow plugs are switched on for between 10 and 20 seconds prior to starting. Older, less efficient or worn engines may need as much as a minute (60 seconds) of pre-heating.

Large diesel engines as used in heavy construction equipment, ships and locomotives do not need glow plugs. Their cylinders are large enough so that the air in the middle of the cylinder is not in contact with the cold walls of the cylinder, and retains enough heat to allow ignition.

automotive diesel engines with electronic injection systems use various methods of altering the timing and style of the injection process to ensure reliable cold-starting. Glow plugs are fitted, but are rarely used for more than a few seconds.

Glow plug filaments must be made of materials such as platinum and iridium that are resistant both to heat and to oxidation and reduction by the burning mixture. These particular materials also have the advantage of catalytic activity, due to the relative ease with which molecules absorbed on their surfaces can react with each other. This aids or even replaces electrical heating.


Model engines

In model aircraft, and similar applications , glow plugs are used for starting as well as continuing the power cycle. The glow plug consists of a durable, mostly platinum, helically wound wire filament, within a cylindrical pocket in the plug body, exposed to the combustion chamber. A small direct current voltage (around 1.5 volts) is applied to the glow plug, the engine is then started, and the voltage is removed. The burning of the fuel/air mixture in a glow-plug model engine, which requires methanol for the glow plug to work in the first place, and sometimes with the use of nitromethane for greater power output, occurs due to the catalytic reaction of the methanol vapor to the presence of the platinum in the filament, thus causing the ignition. This keeps the plug's filament glowing hot, and allows it to ignite the next charge. Since the ignition timing is not controlled electrically, as in a spark ignition engine or by fuel injection, as in an ordinary diesel, it must be adjusted by the richness of the mixture, the ratio of nitromethane to methanol, the compression ratio, the cooling of the cylinder head, the type of glow plug, etc. A richer mixture will tend to cool the filiment and so retard ignition, slowing the engine, and a rich mixture also eases starting. After starting the engine can easily be leaned (by adjusting a needle valve in the spraybar) to obtain maximum power.

Automotive Accessories : Spark Plug Voltage Stabilizer

* for Petrol/Gasoline vehicles

The spark [at the spark plug] is fundamental to cause ignition and thus combustion of the Air/Fuel mixture.

Spark at the spark plug is created by a high voltage that comes from the ignition coil.

The +12 Volt car battery is the main power source to many users of a vehicle; i.e.

* air conditioner
* head-lights
* wipers
* hi-fi and radio
* other electrical items, etc

As such, consistent supply cannot be guaranteed to the ignition coil via the +12 Volt Car Battery. When this happens, the spark may be too small to cause burning of the Air/Fuel mixture, or mis-firing, causing 100% unburn fuel to be released to the environment through the exhaust system.

This is also true when the vehicle is running at high rpm, and sparkings has to take place in shorter interval. So, when the car battery is not able to consistently supply the same power to the ignition coil, smaller or no sparking will occur.


Concept of Work

The Spark Plug Voltage Stabilizer is installed at the front of the ignition coil(s).

The Spark Plug Voltage Stabilizer concept of work is to take residual energy from the car and make it into good use. It relies less of the car battery in supplying the require power to the ignition coil. Revolutionary circuit design allows more Sparks.And this is achieved through a much higher Voltage delivery to the spark plugs.

* Impact of Optimized sparks
o Reducing unburn fuel will improve Fuel Consumption; because of less wastage [unburn fuel].
o The result of better burning improves car response, increasing power to the vehicle.


Types of Ignition Coils

The Spark Plug Voltage Stabilizer works on all different types of Ignition Coil Designs.

Earlier car design has the ignition coil as a separate unit. It is then connected to a 'distributor unit' which will sequence the high voltage generated to the respective spark plug.

Current design for single ignition coil system is called the 'Built-In Coil'. This houses both the Ignition Coil and Distributor as one unit.

* Single Coil - works with a separate Distributor unit
* Built-In Coil - Ignition Coil and Distributor unit in one
* Multi Coil; may be
o 2 Ignition coils
+ 1 Ignition coil to 2 spark plugs, or
+ 1 Ignition coil to 3 spark plugs [V6 engine]
o 3 coils
+ 1 Ignition coil to 1 spark plug, [3 cylinders engine eg. Perodua [Malaysia] or
+ 1 Ignition coil to 2 spark plugs [V6 engine]
o 4 coils
+ 1 Ignition coil to 1 spark plug [DIS - Direct Ignition Coil System, or Distributorles Ignition Coil System]
o More than 4 Coils, such as 6 coils (V6 engine), etc


Factors to better Fuel Consumption

There are many websites giving advice to improve fuel economy. Beside ensuring the vehicles at tip top conditions, the right foot is key! However, to attack the problem at the source; the Spark Plug Voltage Stabilizer has its merit.

Other products are available in the car accessories market to help in this area. Some of them, notably are :

*
o Voltage Stabilizer
o Magnet systems on the fuel line
o Fuel additives
o Cold Air Intake
o Special Air Filters
o Special Engine Oils
o Special Spark Plugs
o Highly Conductive Spark Plug Cables
o Your Right Foot, artificial or otherwise

*
o Latest product in the market : Patented composite material 'Titanium Ceramic' that influence the breaking up of clustered Air Molecules that allow easier combustion in the cylinder.

V-Mounted Intercoolers

The V-Mounted Intercooler is a hybrid system, developed to provide superior air cooling to a front mounted intercooler, yet still retain the short intake piping and radiator airflow of the TMIC. In this case, the intercooler is mounted horizontally, directly in front of the engine (although it can be at an angle). Most VMIC setups place the radiator below the intercooler, at a great angle, tilted back until it is almost touching the motor. Ducts are used in the front of the car to duct air through the intercooler, creating a ram-air effect, while the remainder of the air flows over the radiator, normally. The air is usually removed via a hood vent (a vent recessed into the car's hood near the front of the car; if it is mounted too far back, it will actually suck air into the engine bay), although in the case of a bottom-mounted intercooler, the air is allowed the exit underneath the car (although this is dangerous because is places the intercooler at extreme risk to damage from bumps and rocks). VMIC setups are typically utilized on Front Midship cars, as the location of the engine, far back in the engine bay, allows room for the system.

VMICs were pioneered on the Mazda RX-7, because rotary engines have a tendency to run hot. It was intended to be a compromise between a TMIC or a side-mounted intercooler (2nd Generation and 3rd Generation RX-7, respectively) and a FMIC. An intercooler in the stock position would not support high airflow (and thus limit top power, or create severe detonation in the engine, which damages rotary engines more easily than piston engines), while FMICs would block airflow to the radiator, leading to overheating. The RX-7 is the only car that currently has a VMIC kit available for it. VMICs on other cars are custom made, usually used on track cars and require significant investment and fabricating skills to properly set up and tune.

Front Mount InterCooler

FMICs generally require open bumpers, and front spoilers, which will force air into the bumper and provide down force as well, are also beneficial. In general, because of the location, a front mount intercooler tends to cool air more efficiently than a similarly sized TMIC (top mount intercooler) or a SMIC (side mount intercooler). FMICs have some disadvantages, however. One obvious drawback is the vulnerable position of the intercooler in front of the car - any moderately serious frontal impact will significantly damage the FMIC. FMICs, by virtue of their sitting in front of the radiator, block airflow to the radiator, as the air that passes through the intercooler is several degrees hotter than the air on the other side. While on most piston engines, this is not too major a concern, on hot-running engines, and rotary engines in particular, this can lead to problems. FMICs also require the most plumbing of any intercooler setup, which means that there is much more volume that the turbocharger or supercharger must pressurise before it can deliver positive boost. Because of this, many manufacturers opt to use SMICs or TMICs to avoid excessive turbo lag. Several manufacturers including Ford (with the 2003/04 Mustang Cobra and 2007 GT 500), Mitsubishi (Lancer Evolution) and Dodge (2003-05 SRT-4) are shipped from the factory with FMIC's.

The Gerotor

A Gerotor is a positive displacement pumping unit. The name gerotor is derived from "Generated Rotor". A Gerotor unit consists of an inner and outer rotor. The inner rotor has N teeth, and the outer rotor has N+1 teeth. One rotor is located off-center and both rotors rotate. During part of the assembly's rotation cycle, the area between the inner and outer rotor increases, creating a vacuum. This vacuum creates suction, and hence, this part of the cycle is where the intake is located. Then, the area between the rotors decreases, causing compression. During this compression period, fluids can be pumped, or compressed (if they are gasseous fluids).

A gerotor can also function as a motor. High pressure gas enters the intake area and pushes against the inner and outer rotors, causing both to rotate as the area between the inner and outer rotor increases. During the compression period, the exhaust is pumped out. This is an Otto cycle engine.

An engine created by the Starrotor Corporation combines both uses of a gerotor. It uses the Brayton cycle, the same thermodynamic cycle employed by jet engines. A first gerotor compresses gas, this gas is then ignited in a combustor. The gaseous products of this combustion have a much higher pressure, which drives a second gerotor. Then, some of the output of the second gerotor is used to drive the 1st.

Cylinder head porting

Cylinder head porting is the technology of modifying the intake and exhaust ports of an internal combustion engine to improve the quality and quantity of the gas flow. Cylinder heads as manufactured cannot be optimal due to design and manufacturing constraints. Porting the heads provides the finely detailed attention required to bring the engine to the highest level of efficiency. More than any other single factor porting technology is responsible for the high power output of modern engines.

This process can be applied to a standard racing engine to optimize its power output as well as to a production engine to turn it into a racing engine, to enhance its power output for daily use or to alter its power output characteristics to suit a particular application.

Daily human experience with air gives the impression that air is light and nearly non-existent as we move slowly through it. An engine running at high speed experiences a totally different substance. In that context, air can be thought of as thick, sticky, elastic, gooey and heavy (see viscosity). Pumping it is a major problem for engines running at speed. Porting helps engines deal with this problem.

Air start system

The air start system on a large slow speed diesel engine is used to initiate ignition and consists of the following components: a compressor, an air reservoir (large cylindrical tank), associated piping, a control valve (this is linked to the camshaft), and the air start valves.

When starting the engine, compressed air is admitted to whichever cylinder has a piston just over top dead center, forcing it downward. As the engine starts to turn the air start valve on the next cylinder in line opens to continue the rotation. As this goes on, fuel is injected into the cylinders, the engine is then under way and the air is cut off.

To further complicate matters, a large engine is usually "blown over" first with zero fuel settings and the indicator cocks open, to prove that the engine is clear of any water build up and that everything is free to turn. After a successful blow ahead and a blow astern, the indicator cocks are closed on all the cylinders, and then the engine can be started on fuel.

Compared to a gasoline (petrol) engine, diesels have very high compression ratios to provide for reliable and complete ignition of the fuel without spark plugs. An electric starter powerful enough to turn a large diesel engine would itself be so large as to be impractical, thus the need for an alternative system.

Hydrogen fuel injection

Hydrogen Fuel Injection, or HFI, is a system to reduce exhaust emissions of internal combustion engines and improve fuel economy. HFI systems work by injecting hydrogen as a combustion enhancement into the intake manifold of an internal combustion engine to achieve these benefits. A small amount of hydrogen added to the intake air-fuel charge enhances the flame velocity and thus permits the engine to operate with leaner air-to-fuel mixture than otherwise possible. The result is lower pollution with more power and better mileage.

A simplified single-step combustion reaction is represented as: [FUEL] + [HYDROGEN] + [AIR] -> HC + CO + CO2 + H2O + NOx

For incomplete combustion, the above results in exhaust products including unburned hydrocarbons (HC) and carbon monoxide (CO). The NOx is formed mainly from the combustion air, and is highly temperature-dependent.

In 1974 John Houseman and D.J Cerini of the Jet Propulsion Laboratory, California Institute of Technology produced a report for the Society of Automotive Engineers entitled "On-Board Hydrogen Generator for a Partial Hydrogen Injection Internal Combustion Engine". In the same year, F.W. Hoehn and M.W. Dowy, also of the Jet Propulsion Lab, prepared a report for the 9th Intersociety Energy Conversion Engineering Conference, entitled "Feasibility Demonstration of a Road Vehicle Fueled with Hydrogen Enriched Gasoline." This research utilized onboard storage tanks to supply the hydrogen combustion enhancement.

More recent investigations have highlighted the potential for pollutant reduction. Research performed by scientists at the University of Birmingham, United Kingdom, released a study in June of 1995 at the HYPOTHESIS Conference at the University of Cassino, Italy in which it was presented that "hydrogen, when used as a fractional additive at extreme lean engine operation, yields benefits in improved combustion stability and reduced nitrogen oxides and hydrocarbon emissions." Similar results have been presented by a team of scientists representing the Department of Energy Engineering, Zhejiang University, China in the Spring of 1997 at an international conference held by the University of Calgary. Practical tests have been performed by California Environmental Engineering (CEE), The American Hydrogen Association Test Lab and Corrections Canada in which reduction in toxic exhaust emissions and fuel consumption were realized.

Commercially, Canadian Hydrogen Energy Company, LTD, produces an HFI system which generates hydrogen during vehicle operation by electrolyzing water (from an onboard storage tank) using power from the vehicle's electrical system. In dynamometer tests with 1992 60 series diesel engine fueled by low-sulphur (<15 PPM) diesel fuel, the system draws a maximum of 35 amps (12V DC) and yields 4.44% reduced fuel consumption, 6.17% reduced HC emissions, 0.39% reduces CO emissions, 4.34% reduced NOx emissions, and 7.0% reduced PM (particulate matter) emissions.

Publicly, Canadian Eagle Research Company produces the HyZor on-board electrolyzer that is comparable to coexisting commercial devices primarily being scaled down to fit Sedans, Coupes, SUV's, and Hybrids. A unique feature of the system is its design not to remove oxygen giving the output gas properties extremely similar to the HFI system while eliminating the required ducting components necessary to separate oxygen. These systems are fully automated only requiring occasional refills of distilled water when the system informs the driver by dash mounted led’s controlled by an electronic circuit integrated with the vehicles ignition.

Capacitor discharge ignition

Capacitor discharge ignition (CDI) is a type of automotive electronic ignition system which is widely used in motorcycles, lawn mowers, chain saws, small engines and recently in some cars. Capacitor discharge ignition uses capacitor discharge current output to fire the spark plugs.


The basic principle

Most of typical ignition system used in cars are inductive ignition system, which is solely relying on the electric inductance at the coil to produce high-voltage electricity to the spark plugs. In a CDI system, the system charges a capacitor by default, and during the ignition point the system stopps charging the capacitor, allowing the capacitor to discharge its output to the final coil before reaching the spark plug.

A typical CDI module may consist of a small transformer, a charging circuit, a triggering circuit and a main capacitor. Firstly, the system voltage is raised up to 400 V by a transformer inside the CDI module. Then, the electric current flows to the charging circuit and charges the capacitor. The rectifier inside the charging circuit prevents capacitor discharge before the ignition point.

When the triggering circuit receives triggering signals from triggering devices such as Hall effect sensor or pulse generator during the ignition point, the triggering circuit stops the operation of the charging circuit, allowing the capacitor to discharge its output rapidly to the ignition coil. The rapid capacitor discharge then produces a very high voltage at about 40 kV to be fired at the spark plug. When there's no triggering signal, the charging circuit is re-connected to charge back the capacitor.


CDI modules can be generally divided into two:-

* AC-CDI - The AC-CDI module obtains its electricity source solely from the alternating current produced by the alternator. The AC-CDI system is the most basic CDI system which is widely used in small engines.
* DC-CDI - The DC-CDI module is powered by the battery, and therefore an additional DC/DC inverter circuit is included in the CDI module to raise the 12 V DC to 400 V DC, making the CDI module slightly larger. However, the vehicle that uses DC-CDI system has more precise ignition timing and the engine can be started easier when cold.


Advantages and Disadvantages of CDI

CDI system produces higher ignition voltage (about 40 kV) compared with typical inductive ignition system (about 20 kV). The higher voltage produced by the CDI system produces a hotter spark, enabling the engine to be operated even with badly-fouled spark plugs.

The CDI system also has a faster voltage rise time (between 3 ~ 10 kV/μs) compared with typical inductive systems (300 ~ 500 V/μs). The higher voltage rise time results in a shorter spark duration with the CDI system (10 ~ 12 μs) and therefore the spark output is more accurate.

However, the shorter spark duration means the CDI system is not suitable for sharing between cylinders in multi-cylinder engines. It was not until the end of the 1990s that CDI system could be practically used in multi-cylinder engines, especially in cars, as a result of the development of the direct ignition system, where each cylinder has its own ignition coil.

CDI systems also have problems with lean air-fuel mixture and high compression engines as well as cold-starting problems. However, the problems can be solved by using waste-spark methods.


History

THe history of capacitor discharge ignition system can be traced back in 1950s together with the development of other electronic ignition systems. The first commercial motorcycle using the CDI system was manufactured by Kawasaki.

By the end of 1960s, the US government made new laws enforcing strict emission standards. As a result, more and more electronic ignition systems were developed, and starting from 1970s all smaller engines installed CDI system to replace the contact point system, including Honda Cub which began to use AC-CDI system.

By the end of 1990s, direct ignition system using capacitor discharge ignition system was developed and started to be installed on some newer car models.

Hypereutectic piston

“Hypereutectic” means “Over” eutectic. The word eutectic refers to a condition in chemistry when two elements can be alloyed together on a molecular level, but only up to a specific percentage, at which point any additional secondary element will retain a distinct separate form.

Although internal combustion engine pistons commonly contain trace amounts (less than 2% each) of Copper, Manganese, and Nickel, the major element in automotive pistons is Aluminum due to its light weight, low cost, and acceptable strength. The alloying element of concern in automotive pistons is Silicon. Gold and Silver have no eutectic point, which means they can be alloyed together in any ratio. However, when Silicon is added to Aluminum they will only blend together evenly on a molecular level up to approximately a 12% Silicon content. For the purposes of this discussion, Silicon in this context can be thought of as “powdered sand”, and any Silicon that is added to aluminum at above a 12% content will retain a distinct granular form instead of melting. At a blend of 25% Silicon, there is a significant reduction of strength in the piston alloy, so stock hypereutectic pistons commonly use a level of Silicon between 16% and 19%. Special molds, casting, and cooling techniques are required to obtain uniformly dispersed silicon particles throughout the piston material.


The reason for their development

Most automotive engines use aluminum pistons that cycle in a steel cylinder. The average temperature of a piston crown in a gasoline engine during normal operation is typically about 600 degrees Fahrenheit, and the coolant that runs through the engine block is usually regulated at approximately 190 degrees F. Aluminum expands more than steel at this temperature range, so for the piston to fit the cylinder properly when at a normal operating temperature, the piston must have a loose fit when cold.

In the 1970’s, increasing concern over exhaust pollution caused the U.S. government to form the Environmental Protection Agency (EPA) which began passing legislation that forced auto manufacturers to make changes that allowed their engines to run cleaner. By the late 1980’s, auto exhaust pollution had been noticeably improved, but increasingly stringent regulations forced car manufacturers to adopt the use of electronically controlled fuel injection and hypereutectic pistons. It was discovered that when an engine is cold, a small amount of excess fuel during start-up became trapped between the piston rings. This admittedly small quantity of excess fuel affected the amount of hydrocarbons in the exhaust when the piston expanded as it warmed, and then expelled the excess fuel.

By adding Silicon to the pistons alloy, the amount the piston expanded could be dramatically reduced, which allowed engineers to specify a much tighter cold-fit. Silicon itself expands less than Aluminum, and it also acts as an insulator to prevent the Aluminum from absorbing as much of the operational heat as it otherwise would. Another beneficial effect of adding Silicon is that the piston becomes harder, and is less susceptible to scuffing, which can occur when a soft aluminum piston is cold-revved in a relatively dry cylinder on start-up.

The biggest drawback of piston Silicon is that the piston becomes more brittle as more Silicon is added, which allows the piston to develop cracks easier if the engine experiences pre-ignition or detonation.


Performance replacement alloys

When an auto enthusiast wants to increase the power of their engine, they often add some type of forced induction. By compressing more air and fuel into each intake cycle, the power of the engine can be dramatically increased. This also increases the heat and pressure in the cylinder.

The normal temperature of gasoline engine exhaust is approximately 1200 F. This is also approximately the melting point of most Aluminum alloys, and it is only the constant influx of ambient air that prevents the piston from deforming and failing due to excess temperatures. Forced induction increases the operating temperatures while “under boost”, and if the excess heat is added faster than engine can shed it, the elevated cylinder temperatures will cause the air and fuel mix to auto-ignite on the compression stroke before the spark event. This is one type of engine knocking that causes a sudden shock wave and pressure spike, which can result in an immediate and catastrophic failure of the piston and connecting rod.

The “4032” performance piston alloy has an approximate Silicon content of 11%. This means that it expands from heat less than a piston with no Silicon, but since its eutectic level of Silicon is fully alloyed on a molecular level, this alloy is less brittle and more flexible than a stock Hypereutectic “smog” piston. These pistons can survive mild detonation with less damage than stock pistons.

The “2618” performance piston alloy has less than 2% Silicon and could be described as Hypo (under) eutectic. This alloy is capable of experiencing the most detonation and abuse while suffering the least amount of damage. Pistons made of this alloy are also typically made thicker and heavier because of their most common applications. Because of the higher than normal temperatures these pistons experience in their usual application, and also the low-Silicon content allowing the maximum possible Aluminum heat-expansion, these pistons have their cylinders bored to a very loose cold-fit. This leads to a condition known as “piston slap” which is when the piston rocks in the cylinder, and it causes an audible tapping noise that continues until the engine has warmed to operational temperatures. These engines should not be revved when cold, or excessive scuffing can occur.


Forged versus Cast

When a piston is cast, the alloy is heated until it is a liquid, and then it is poured into a mold to create its basic shape. After the alloy cools and solidifies, it is removed from the mold, and then the rough casting is machined to its final shape. When a piston is desired that is stronger than what simple casting can provide, they can be forged. This is when the rough casting is placed in a die set while it is still hot, and a hydraulic press is used to place the rough slug under a tremendous amount of pressure. This removes any possible porosity and also pushes the alloy grains together tighter than what can be achieved by simple casting alone, resulting in a much stronger material.

Hypereutectic pistons can be forged, but typically are only cast. This is because cast pistons are considered strong enough for stock applications, and the extra expense is not justified.

Aftermarket performance pistons made from the most common 4032 and 2618 alloys that are often used to replace stock hypereutectic pistons are typically forged.

Short Long Arms Suspension

An SLA is also known as an unequal length double wishbone suspension. The upper arm is typically an A-arm, and is shorter than the lower link, which is an A-arm or an L-arm, or sometimes a pair of tension/compression arms. In the latter case the suspension can be called a multi-link, or Dual ball joint suspension.

The four bar link mechanism formed by the unequal arm lengths causes a change in the camber of the vehicle as it rolls, which helps to keep the contact patch square on the ground, increasing the ultimate cornering capacity of the vehicle. It also reduces the wear of the outer edge of the tire.

SLAs can be classified as short spindle, in which the upper ball joint on the spindle is inside the wheel, or long spindle, in which the spindle tucks around the tire and the upper ball joint sits above the tire.

Checking the automatic transmission fluid

Place your car at a level surface and engage the parking brake. Start the engine. Set transmission shifter in "P" (Park) position, and let the engine idle (on some cars this procedure may be different, check the owners' manual for details). Pull the transmission dipstick. Check your owners manual to find where transmission dipstick is located in your car.

Wipe it off with a clean lint free rag. Then insert it back carefully all the way down into its place.

Pull again and check the fluid level. If the engine is cold, it should be within "COLD" marks. If the car was driven and is fully warmed up, the level should be at the upper end of the "HOT" mark. If it's just a little bit lower I wouldn't worry about it. Otherwise I'd top it up. Check the fluid condition also: If it's too black and dirty with burnt smell - your transmission is not going to last. Normally it should be clean and transparent, as in the image. The new fluid comes red. Over the time it becomes brownish. If it is brown, check your owner's manual, may be it's time to change it. Some manufacturers require to change the transmission fluid at 30,000 or 50,000 miles others specify that you never have to change it - check what's your car owner's manual says.

How to top up the transmission fluid:
It's very important to use only specified transmission fluid - check your owners manual or simply visit your local dealer, they alway have proper transmission fluid in stock. Incorrect transmission fluid can even destroy the transmission. Add a small amount of the fluid through the dipstick pipe as shown in the image. Wait for a few minutes - let the fluid to flow down. Recheck the level again. Do not overfill, it also may cause problems with your transmission.

Multi-valve

In automotive engineering, an engine is referred to as multi-valve (or multivalve) when each cylinder has more than two valves.

All poppet valve, four-stroke internal combustion engines have at least two valves per cylinder — one for intake of air and fuel, and another for exhaust of combustion products. Adding more valves improves the flow of intake and exhaust gases, potentially improving combustion efficiency, power, and performance. It is not practical to simply use two larger valves because of the circular shape of the combustion chamber and the need for valves to also be round, which ensures they can only cover a fraction of the top of each cylinder; three (or more) smaller valves can replace the largest two valves which could be fitted into the space and result in having a greater effective valve area. Adding more valves per cylinder can improve breathing and thus allow an engine to run at a higher RPM, creating more power for a given displacement, though at a greater complexity and cost.

Most multivalve engines use an overhead camshaft to actuate the valves, and many use double overhead camshafts (DOHC). However this is not always the case: Chevrolet recently showed a 3-valve version of its Generation IV V8 which uses pushrods to actuate forked rockers, and Cummins makes a 4-valve pushrod straight-6 Diesel, the Cummins 600.

Starting in 1922, many of Bugattis engines began using 3 valves per cylinder actuated by a single-ovehead-cam (SOHC). Nissan has produced the 1988-96 KA24E engine with 3 valves per cylinder (two intakes, one exhaust) that are also actuated by (SOHC). Mercedes and Ford are currently producing V6 and V8 engines using this configuration. Ford claims an 80% improvement in high RPM breathing without the added cost of a second cam per bank of cylinders. The Ford design uses one spark plug per cylinder located in the center, but the Mercedes design uses two spark plugs per cylinder located on opposite sides, leaving the center free to add a direct-to-cylinder fuel injector at a later date. Thus there are many considerations to deciding how many valves an engine should have besides just the added cost verses adding breathing capability.

Some versions of the Honda D-series 4 cylinder engines and all J-series V6 and R-series 4 cylinder engines actuate 4 valves per cylinder with a single overhead cam.

Volkswagen, Audi, Ferrari and Yamaha have introduced engines in the past that had a double overhead cam operating 5 valves per cylinder (three intakes, two exhaust). Toyota's 1991-98 4A-GE 1.6-liter 4-cylinder engine also uses 5-valves-per-cylinder and was co-designed by Yamaha as well.

Maserati has produced a 2.0L turbo-V6 engine with 6 valves-per-cylinder (three intakes, three exhaust) (http://www.maserati-alfieri.co.uk/alfieri26.htm).

Engines with two or four valves per cylinder are by far the most common configurations. Four valve per cylinder engines are typically actuated by DOHC, and are too numerous to list.

NOx Adsorbers

The NOx Adsorber or NOx Trap is a device that is use to reduce NOx (NO and NO2) emissions from a lean burn internal combustion engine.


Purpose and Function of a NOx Adsorber

A NOx Adsorber is designed to reduce oxides of nitrogen emitted in the exhaust gas of a lean burn internal combustion engine. Lean burn (diesel) engines present a special challenge to emission control system designers because of the relatively high levels of O2 (atmospheric Oxygen) in the exhaust gas stream. The 3-Way Catalytic Converter technology that has been successfully used on Rich Burn Internal Combustion Engines (typically fueled by petrol but also sometimes fueled by LPG, CNG, or Ethanol) since the middle 1980s will not function at O2 levels in excess of 1.0%, and does not function well at levels above 0.5%. Because of the increasing need to limit NOx emissions from Diesel engines technologies such as Exhaust gas recirculation (EGR) and Selective catalytic reduction (SCR) have been used, however EGR is limited in its effectiveness and SCR requires a reductant, and if the reductant tank is emptied the SCR system ceases to function.

The NOx Adsorber was designed to avoid the problems that EGR and SCR experienced as NOx reduction technologies. The theory is that the zeolite will trap the NO and NO2 molecules - in effect acting as a molecular sponge. Once the trap is full (like a sponge full of water) no more NOx can be adsorbed, and it is passed out of the exhaust system. Various schemes have been designed to "purge" or "regenerate" the adsorber. Injection of diesel fuel (or other reactant) before the adsorber can purge it - the NO2 in particular is unstable and will join with Hydrocarbons to produce H2O and N2. Use of Hydrogen has also been tried, with the same results, however Hydrogen is difficult to store. Some experimental engines have mounted Hydrogen reformers for on board Hydrogen generation, however Fuel Reformers are not mature technology.

NOx Adsorbers are experimental technology as of early 2006, and thus extremely expensive. Whether or not this technology will be successfully commercialized is open to question - only time will tell.


Technical Details

The NOx Adsorber is based on a catalytic converter support that has been coated with a special washcoat containing zeolites.

Dry sump

A dry sump is a lubricating oil management method for four-stroke and large two-stroke piston internal combustion engines that uses a secondary external reservoir for oil, as compared to a conventional wet sump system.

Four-stroke engines are lubricated by oil which is pumped into various bearings and thereafter allowed to drain to the base of the engine. In most production cars, which use a wet sump system, this oil is simply collected in a three to seven litre capacity pan at the base of the engine, known as the oil pan where it is pumped back up to the bearings by the oil pump, internal to the engine. In a dry sump, the oil still falls to the base of the engine, but rather than being collected into an oil pan, it is pumped into another reservoir by one or more scavenger pumps, run by belts from the front or back of the crankshaft. Oil is then pumped from this reservoir to the bearings of the engine by the pressure pump. Typical dry sump systems have the pressure pump and scavenger pumps "stacked up", so that one pulley at the front of the system can run as many pumps as desired, just by adding another to the back of the stack.

A dry sump affords many advantages, namely increased oil capacity, decreased parasitic loss and a lower center of gravity for the engine. Because the reservoir is external, the oil pan can be much smaller in a dry sump system, allowing the engine to be placed lower in the vehicle; in addition, the external reservoir can be as large as desired, whereas a larger oil pan raises the engine even further. Increased oil capacity by using a larger external reservoir leads to cooler oil. Furthermore, dry sump designs are not susceptible to the oil starvation problems wet sump systems suffer from if the oil sloshes in the oil pan, temporarily uncovering the oil pump pickup tube. Having the pumps external to the engine allows them to be maintained or replaced more easily, as well.

Dry sumps are common on larger diesel engines such as those used for ship propulsion. Many race cars, supercars, and aerobatic aircraft also utilize dry-sump equipped engines because they prevent oil-starvation at high g loads and because their lower center of gravity positively affects performance.

Charge air cooler

A charge air cooler (also known as an intercooler) is used to cool engine air after it has passed through a turbo charger, but before it enters the engine. The idea is to return the air to the optimum temperature for the combustion of the engine.

Charge air coolers range in size depending on the engine. The smallest are most often referred to as intercoolers and are attached to auto engines or truck engines. The largest are reserved for use on huge marine diesel engines and can weigh over 2 tonnes (see picture).

Marine diesel engine charge air coolers are manufactured in Europe still, despite the very largest engines mostly being built in the Far East. Vestas aircoil A/S and GEA are the oldest makers still in business.

The first marine diesel engine charge air cooler was built by Vestas aircoil A/S in 1956!







4-stroke diesel engine coolers










Location of cooler on large diesel engine

How to Clean a Car Battery

What You Need

* Baking Soda and Stiff Brush
* Rubber Gloves
* Wrench to Fit Cable Clamp
* Wrench to Remove Battery
* Waterproof Grease

1. After loosening the cable clamps and battery holder, remove the battery from vehicle.

2. Begin by cleaning the entire battery top of dirt and oxidation using baking soda and water.

3. While battery is out, clean the cable clamps until shiny with the #535 brass brush.

4. Re-install battery in vehicle. Re-attach clamps and cover the connection with grease.

Belt alternator starter

General Motors introduced a mild hybrid system called belt alternator starter (or BAS) in the 2006 Saturn VUE Green Line. It operates similar to the "start-stop" system used in the Chevrolet Silverado Hybrid in that it shuts down the engine when the vehicle comes to a stop and instantly restarts it when the accelerator is pressed. A 48 volt electrical system is used to operate all accessory equipment, from the air conditioning to the lighting, making the system essentially invisible to the driver.

The BAS system goes slightly further than the Silverado, however, in providing some modest power assist for "acceleration feel", according to GM. Although not as effective as other systems, the BAS system is expected to provide about 15% fuel efficiency gain for the compact VUE.

One major benefit of the BAS technology is that it fits in the same space as a conventional engine. No modifications were required to the VUE's chassis to accommodate the BAS system, with the battery pack housed in the spare tire well. This allows the VUE Green Line to be produced on the same assembly line as the normal VUE, producing substantial cost savings and allowing the company to adjust production more easily.

The BAS system uses a conventional 4T45-E automatic transmission.

This system will eventually find its way to other GM models, including the Saturn Aura, and Chevrolet Malibu.

Multi-Displacement System

DaimlerChrysler's Multi-Displacement System (MDS) is an automobile engine variable displacement technology. It debuted in 2004 on the 5.7 L modern Hemi V8. Like Mercedes-Benz's Active Cylinder Control, General Motors' Displacement on Demand, and Honda's Variable Cylinder Management, it deactivates four of the V8's cylinders when the throttle is closed.

The system was first offered only on passenger cars, since the heavy demands of trucks would interfere with its operation. However, it was recalibrated for 2006 and will be offered on all seven models, including trucks, using the 5.7 L engine.

Chrysler expects that the technology will boost economy by 10% to 20%. In the Jeep Grand Cherokee with MDS, highway fuel mileage for the V8 is the same as the V6 at 21 mpg (11.2 liters per 100 km).

In order to preserve the characteristic rumble of the V8 engines, Chrysler and Eberspaecher North America designed a special exhaust system for MDS-equipped vehicles. This includes four separate mufflers, two large central ones for V8 mode and two smaller ones near the tailpipes for straight-4 operation. Unlike the system used on Mercedes-Benz V12 engines, also designed by Eberspaecher, the system is mechanically passive.

Applications:

* 2005- Chrysler 300C
* 2005- Dodge Charger
* 2005- Dodge Magnum
* 2005- Jeep Grand Cherokee
* 2006- Dodge Durango
* 2006- Dodge Ram
* 2006- Jeep Commander

Power band

The power band of an engine refers to the range of operating speeds under which the engine is able to operate efficiently. A typical gasoline automotive engine is capable of operating at a speed of between around 750 and 6000 RPM, but the engine's power band would be more limited. The engine would typically not generate maximum torque until higher operating speeds of perhaps 2500 RPM, after such, the torque drops off. The peak power (horsepower) might be closer to 5000 RPM. Such an engine would be said to have a "power band" of 2500-5000 RPM (another example would be from torque peak to redline: 2500-6000 RPM).

A more precise definition of the power band: the rpm range where an engine makes at least 75% of its maximum torque.

This can be applied to any engine and establishes a reliable quantification of the above notion "the engine is able to operate efficiently".



Power Band Tuning Considerations

The tuning of the power band is a great challenge. It is possible to create a peaky engine which generates more power from an engine if the manufacturer is willing to tune it for a very narrow power band. However, an engine with a narrow power band is more difficult to use. Such an engine must be coupled to a close-ratio transmission with many gears in order to remain in its power band while providing an acceptably wide range of output speeds. A flexible engine has a wide power band with less peak power, but could be tied to a less complex transmission with fewer gears and would not need to shift gears as often. Such an engine is also often called torquey because it maintains a more constant level of torque over a wider range of RPM.


Cost and Usage Considerations

Sports cars and other performance vehicles are generally designed for peak power in a narrow power band. In these vehicles, the higher cost of a complex transmission would be more acceptable, and the driver could be assumed to be more willing to shift gears often to remain in the power band. These vehicles attempt to achieve the greatest possible power to weight ratio, and benefit greatly from using a smaller engine tuned for high peak power rather than a large engine with a wide power band. Trucks and full-size cars are more often tuned for a wide power band and use larger engines to achieve acceptable power over a wide range. These vehicles have the benefit of not having to shift as often as vehicles with a narrow power band.


Tuning for high Horsepower Output or high Torque Output?

Since automobile shoppers rely heavily on the peak power output figure (typically given in horsepower or kilowatts), some auto makers tend towards producing "peaky" engines. For example, Honda's 2006 Civic Si generates 197 hp (147 kW) at 7800 RPM. Though it produces a fairly flat torque curve compared to many engines, it only produces 139 ft·lbf (188 N·m) and it has relatively sharp (or "peaky") power delivery, this requires the driver to keep the engine at high RPM to extract the best performance from the Civic. In contrast, Volkswagen's 2006 GTI 2.0T produces about 200 hp (149 kW) from 5,100 RPM to 6,000 RPM and a relatively flat torque band of 207 ft·lbf (281 N·m) from 1,800 to 5,000 RPM. This wide power delivery makes it easier for the driver to extract the vehicles best performance.


Power band considerations with a CVT vehicle

Because a CVT vehicle has the capability of keeping RPMs within the crest of the power band under acceleration, a peaky engine is optimal. Under full acceleration 100% of the available power can be extracted at all times. There is no shifting, and no moving out of the power band. This type of transmission is more efficient than others due to power band issues mentioned previously, but is not favored by many due to the lack of apparent power. Drivers are accustomed to the sudden lurch off the line and the shifting of the transmission. Though these are only actions of less efficient transmission, some vehicle manufacturers have computerized such events in to the transmission to add to the perception of power and torque.


Non-Automotive Power Band Tuning

Engines for ships and aircraft are also generally designed with a narrow power band as these vehicles do not have to operate over a wide speed range. They instead reach their optimal operating speed and remain there for the duration of their trips. As a result, they benefit from tuning for peak power and efficiency in a narrow power band.

Injection pump

An Injection Pump is the device that pumps fuel into the cylinders of a diesel engine or less typically, a gasoline engine. Traditionally, the pump is driven indirectly from the crankshaft by gears, chains or a toothed belt (often the timing belt) that also drives the crankshaft on overhead-cam engines (OHC). It rotates at half crankshaft speed in a conventional four-stroke engine. Its timing is such that the fuel is injected only very slightly before top dead-centre of that cylinder's compression stroke. It is also common for the pump belt on gasoline engines to be driven directly from the camshaft.

Because of the need for positive injection into a very high-pressure environment, the pump develops great pressure—typically 15,000 psi (100 MPa) or more on newer systems. This is a good reason to take great care when working on diesel systems; escaping fuel at this sort of pressure can easily penetrate skin and clothes, and be injected into body tissues with serious consequences.

Earlier diesel pumps used an in-line layout with a series of cam-operated injection cylinders in a line, rather like a miniature inline engine. The pistons have a constant stroke volume, and injection volume (ie, throttling) is controlled by rotating the cylinders against a cut-off port that aligns with a helical slot in the cylinder. When all the cylinders are rotated at once, they simultaneously vary their injection volume to produce more or less power from the engine. Inline pumps still find favour on large multi-cylinder engines such as those on trucks, construction plant, static engines and agricultural vehicles.

For use on cars and light trucks, the rotary pump or distributor pump was developed. It uses a single injection cylinder driven from an axial cam plate, which injects into the individual fuel lines via a rotary distribution valve. Later incarnations such as the Bosch VE pump vary the injection timing with crank speed to allow greater power at high crank speeds, and smoother, more economical running at slower revs. Some VE variants have a pressure-based system that allows the injection volume to increase over normal to allow a turbocharger or supercharger equipped engine to develop more power under boost conditions.

All injection pumps incorporate a governor to cut fuel supply if the crank speed endangers the engine - the heavy moving parts of diesel engines do not tolerate overspeeding well, and catastrophic damage can occur if they are over-revved.

Mechanical pumps are gradually being phased out in order to comply with international emissions directives, and to increase performance and economy. Alternatives include common rail diesel systems and unit direct injection systems. These allow for higher pressures to be developed, and for much finer control of injection volumes compared to mechanical systems.

Catalytic Converter Technical Details

The catalytic converter consists of several components:

1. The core, or substrate. In modern catalytic converters, this is most often a ceramic honeycomb, however stainless steel foil honeycombs are also used. The purpose of the core is to "support the catalyst" and therefore it is often called a "catalyst support". The ceramic substrate was invented by Rodney Bagley, Irwin Lachman and Ronald Lewis at Corning Glass for which they were inducted into the National Inventors Hall of Fame in 2002.

2. The washcoat. In an effort to make converters more efficient, a washcoat is utilized, most often a mixture of silicon and aluminium. The washcoat, when added to the core, forms a rough, irregular surface which has a far greater surface area than the flat core surfaces, which is desirable to give the converter core a larger surface area, and therefore more places for active precious metal sites. The catalyst is added to the washcoat (in suspension) before application to the core.

3. The catalyst itself is most often a precious metal. Platinum is the most active catalyst and is widely used. However, it is not suitable for all applications because of unwanted additional reactions and/or cost. Palladium and rhodium are two other precious metals that are used. Platinum and rhodium are used as a reduction catalyst, while platinum and palladium are used as an oxidization catalyst. Cerium, iron, manganese and nickel are also used, though each has its own limitations. Nickel is not legal for use in the European Union (due to nickel hydrate formation). While copper can be used, its use is illegal in North America due to the formation of dioxin.


Rich Burn Spark Ignition Engines

Catalytic converters are used on spark ignition (gasoline; liquified petroleum gas (LPG); flexible fuel vehicles burning varying blends of E85 and gasoline; compressed natural gas (CNG)) engines; and compression ignition (diesel) engines.

For spark ignition engines the most commonly used catalytic converter is the three-way converter, which works best used on engines equipped with closed-loop feedback fuel mixture control employing an oxygen (lambda) sensor. While a 3-way catalyst can be used in a open-loop system (and has been for years in the non-road engine market), NOx conversions tend to be less than stellar - and since World emissions regulations are primarily aimed at NOx reduction, open loop fuel systems are now obsolete. To keep the air fuel ratio at stoichiometric (14.7:1 for gasoline), closed loop fuel systems are either fuel injection or a carburetor equipped for feedback mixture control. Within that band, conversions are very high, sometimes approaching 100%. However, outside of that band, conversions tend to fall off very rapidly (see bell curve). Two-way converters have been abandoned on spark ignition engines, due to an inability to control NOx.

A three-way catalyst reduces emissions of CO (carbon monoxide), HC (hydrocarbons), and NOx (nitrogen oxides) simultaneously when the oxygen level of the exhaust gas stream is below 1.0%, though performance is best at below 0.5% O2. Unwanted reactions, such as the formation of H2S (hydrogen sulfide) and NH3 (ammonia), can occur in the three-way catalyst. Formation of each can be limited by modifications to the washcoat and precious metals used. It is, however, difficult to eliminate these side products entirely.

For example, when control of H2S (hydrogen sulfide) emissions is desired, nickel or manganese is added to the washcoat - both substances act to block the adsorption of sulfur by the washcoat. H2S is formed when the washcoat has adsorbed sulfur during a low temperature part of the operating cycle, which is then released during the high temperature part of the cycle and the sulfur combines with HC. For "lean burn" spark ignition engines (e.g. compressed natural gas, or compressed natural gas with diesel fuel pilot injection), an oxidation catalyst is used in the same manner as in a compression ignition engine.

Recently, systems have used a separate early catalytic converter in the system to reduce startup emissions and burn off the hydrocarbons from the extra-rich mixture used in a cold engine. Also, upstream and downstream parts are now often separated in the system to provide an optimum temperature and space for extra oxygen sensors. The converter needs to be placed close enough to the engine to quickly reach operating temperature but far enough away to avoid heat damage.

Early three-way catalytic converters utilized an air tube between the first part of the converter (the NOx part) and the second part, which is virtually unchanged from earlier two-way catalytic converters. This tube was fed by either an air pump (derived from the earlier A.I.R. systems) or by a Pulse Air system. The extra oxygen was used to offset the less precise control of earlier systems by providing the oxygen for the catalyst's oxidizing reaction. The first section was still prone to difficulties on lean conditions with too much oxygen for the NOx reduction to be complete, but the second section always had oxygen available. These systems also commonly included an upstream air injector, either a modified A.I.R. system or another opening in the manifold, to add oxygen into the system to burn the extra-rich mixture used in a cold engine and to allow the additional burning to happen as close to the converter as possible to heat it up to operating temperature quickly.

Newer systems use several techniques to avoid the air tubes. They provide a constantly varying mixture that quickly cycles lean and rich mixtures to keep the first catalyst (NOx reduction) from becoming oxygen loaded and the second catalyst (CO oxidization) sufficiently oxidized, which is less of a concern due to the oxygen created in the first section. They also utilize several oxygen sensors to monitor the exhaust, at least one before the catalytic converter for each bank of cylinders, and one after the converter. Newer systems also often have several units mounted along the pipe to provide different functions rather than one monolithic system.


Diesel Engines

For compression ignition (i.e., Diesel) engines, the most commonly used catalytic converter is the diesel oxidation catalyst. The catalyst uses excess O2 (oxygen) in the exhaust gas stream to oxidize CO (Carbon Monoxide) to CO2 (Carbon Dioxide) and HC (hydrocarbons) to H2O (water) and CO2. These converters often reach 90% effectiveness, virtually eliminating diesel odor and helping to reduce visible particulates (soot), however they are incapable of reducing NOx as chemical reactions always occur in the simplest possible way, and the existing O2 in the exhaust gas stream would react first.

To reduce NOx on a compression ignition engine it is necessary to change the exhaust gas - two main technologies are used for this - selective catalytic reduction (SCR) and NOx (NOx) traps (or NOx Adsorbers).

Another issue for diesel engines is particulate (soot). This can be controlled by a soot trap or diesel particulate filter (DPF), as catalytic converters are unable to affect elemental carbon (however they will remove up to 90% of the soluble organic fraction). A clogging soot filter creates a lot of back pressure decreasing engine performance. However, once clogged, the filter goes through a regeneration cycle where diesel fuel is injected directly into the exhaust stream and the soot is burned off. After the soot has been burned off the regeneration cycle stops and injection of diesel fuel stops. This regeneration cycle will not affect performance of the engine.

All major diesel engine manufacturers in the USA (Ford, Caterpillar, Cummins, Volvo, MMC) starting January 1, 2007 are required to have a catalytic converter and a soot filter inline, as per a new DoT legislation.


Oxygen storage

In order to oxidize CO and HC, the catalytic converter also has the capability of storing the oxygen from the exhaust gas stream, usually when the air fuel ratio goes lean. When insufficient oxygen is available from the exhaust stream the stored oxygen is released and consumed. This happens either when oxygen derived from NOx reduction is unavailable or certain maneuvers such as hard acceleration enrich the mixture beyond the ability of the converter to compensate.

Catalyst poisoning and deactivation

Catalytic converters become ineffective in the presence of lead due to catalyst poisoning. Therefore, vehicles equipped with catalytic converters must only be run on unleaded gasoline, and it is this fact, as much as concerns about the possibly harmful effects of lead emissions, which caused the end of pump-available leaded gasoline in countries where catalytic converters have been in common use for many years. Leaded "race only" fuel is still used for non-catalyst vehicles in some countries where it is no longer legal for road use. Catalyst poisoning occurs when a substance in the engine exhaust coats the surface of the catalyst, preventing further exhaust access to the catalytic materials. Poisoning can sometimes be reversed by running the engine under a very heavy load for an extended period of time to raise exhaust gas temperature, which may cause liquefaction or sublimation of the catalyst poison. Common catalyst poisons are lead, sulfur, zinc, manganese, silicon and phosphorus.

Zinc, phosphorus and sulfur originate from lubricant antiwear additives such as ZDDP; sulfur and manganese primarily originate from fuel impurities or from additives such as Methylcyclopentadienyl Manganese Tricarbonyl (MMT), respectively. Silicon poisoning in automotive applications is the result of engine damage, such as a faulty cylinder head gasket or cracked casting, admitting silicate-containing coolant into the combustion chamber. In stationary engines silicon poisoning is more often caused by the use of "Landfill" gas as a fuel.

Removal of sulfur from a catalyst surface by running heated exhaust gases over the catalyst surface is often successful; however, removal of lead deposits in this manner is usually not possible because of lead's high boiling point. In particularly bad cases of catalyst poisoning by lead, the catalytic converter can actually become completely plugged with lead residue.

A variety of conditions may cause the catalyst to overheat (heat deactivation) and potentially to melt down. Some factors that can cause this are:

* lubricating oil in the exhaust system (caused by engine wear, or by damaged rings or valves)

* an engine misfire or ignition failure (causing unburnt fuel to enter the exhaust)

* a cracked exhaust valve (again, causing unburnt fuel in the exhaust)

Overly rich fuel mixtures are not usually a problem - there is too little unused oxygen for the exotherm to be large enough to cause damage. A slightly lean of stoichiometric mix is far more dangerous, as the oxygen level is elevated, allowing a very large exotherm, and many engine manufacturers design "rich excursions" as a catalyst protection measure in the engine control software. In the early days of catalyst-equipped cars, (primarily in the USA) before the advent of sophisticated engine management systems, it was necessary for fuel/air mixtures to be significantly richer than had hitherto been the case to allow the catalyst to work effectively. This contributed to the very poor fuel consumption figures achieved by such cars.

Engine misfires can overheat and destroy the converter as the excessive amounts of unburned fuel are broken down within it, especially when the engine is under heavy loads. Vehicles equipped with OBD-II diagnostic systems are designed to alert the driver of a misfire condition, along with other malfunctions, using the Malfunction Indicator Lamp or "Check Engine" light. If the misfire and engine load can produce heating severe enough to cause catalyst damage, the MIL will flash until the misfire or engine load is reduced.