Catalytic Converter Properties

Monday, November 17, 2014 | Labels: , , | 0 comments |
Catalytic Converter Properties

Although automobiles may represent one of the most useful, convenient inventions of the modern age, they also represent one of the largest sources for pollution. Devices called catalytic converters reduce this pollution in large part by using an ingenious chemical method that has stood the test of time with only minimal inements.

Why They Are Necessary

    Internal combustion engines mix air and fuel (usually gasoline or diesel) in precise amounts. A timed spark plug ignites this compressed mixture inside a sealed cylinder, and this combustion process basically gives a vehicle its power. After the process finishes, whats left of the mixture exits out of the cylinder through one of its valves; this repeats itself several thousand times per minute. Achieving the right mixture of air and fuel is very difficult, but even in perfect conditions some unburned fuel exits the cylinder. This unused fuel, made up mainly of substances that include hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxide (NOx), would pollute the air if it came out unchecked through the vehicles exhaust gas.

Explaning Catalysts

    A catalytic converter essentially "cleans up" engine emissions by changing them to safer, less-polluting substances. It does this by means of a catalyst. To know what a catalyst does, you need to brush up on Chemistry 101. In normal conditions, a chemical reaction needs a certain amount of energy for it to occur. A catalyst simply reduces the amount of energy needed for such a reaction to take place. In other words, a catalyst makes it easier for a substance to chemically combine with another. Commonly, a different substance altogether results from this chemical combination.

How Catalytic Converters Work

    Specifically, a catalytic converter needs to change harmful molecules that have escaped the engines combustion process, namely HC, CO and NOx. The catalyst facilitates the reaction of these molecules with oxygen in a process known as oxidation. Through this process, the catalyst turns HC and CO into carbon dioxide and water, substances much less harmful to the environment. The catalyst consists of a thin coating usually made of platinum. The coating is applied to a substrate material---basically a porous honeycomb made of ceramic or metal---that the gases must come through to react with the catalyst. Platinum molecules are so small that their atoms are close to the surface and act as a kind of glue to which the unburned fuel briefly adheres itself to. This in turn facilitates their reaction with the oxygen and results in their benign transformation, according to Louis Bloomfield, a physics teacher at the University of Virginia and author of the book "How Everything Works."

Types of Catalytic Converters

    "Two-way" converters, which perform the process just described, were introduced in passenger vehicles since the 1975 model year. To address the NOx emissions three-way converters were developed, which added an additional step ---called reduction--- to the oxidation process carried out by two-way converters. This entailed first "cleaning up" NOx emissions by splitting them into its nitrogen and oxygen components, and then carry out the oxidation process as before. This proved a challenge because the reduction process required the gases coming out of the engine to have a rich air/fuel mix, meaning theres plenty of unburned fuel in the gas, while the oxidation process required the mix to be the exact opposite, a lean air/fuel mix. Early three-way converters got around this problem by introducing oxygen between the reduction and oxidation stages to even the playing field in both stages, according to CatalyticConverter.org, an industry sponsored site organized to provide automotive consumer education. Modern three-way converters combine their work with oxygen sensors and more efficient engines that change back and forth between lean and rich conditions to cut back on unburned pollutants.

Possible Failures

    One of the shortcomings of catalytic converters is that they need to be at a certain temperature to work. That means they dont work in the first few minutes after you turn on your car. Ironically, the most likely way a catalytic converter could break down is by overheating. This would happen usually as a result of too much unburned fuel coming down from the engine. In the days of leaded gasoline, lead could damage the device by placing a coating over the catalysts and obstructing them. Other possible failures include sudden changes in temperature that can damage the ceramic substrate or physical damage caused by impacts with road debris.

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How Can I Stop My Toyota From Smoking Black Smoke

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How Can I Stop My Toyota From Smoking Black Smoke?

Several different engine issues may be present if your exhaust pipe is putting out black smoke. In a Toyota or any other make of car, black smoke is a key indicator that the fuel/air mixture is out of whack. All cars use a specific ratio of fuel and air in the combustion chamber; if the percentage of fuel rises beyond specifications, the mixture is too rich and black smoke is the result.

Instructions

Diagnosing Black Exhaust Smoke

    1

    Check your air filter, which is a common source of a too-rich fuel/air ratio. Taking in dust, grit and smoke from the road, the filter can get clogged and lose its ability to pass an adequate supply of air into the carburetor and engine. Remove the air filter and, if it is dirty or full of grit and/or sand, throw it away.

    2

    Inspect the carburetor by removing the air filter, which rides on top of the carburetor. A small rectangular flap known as a choke plate is fixed longitudinally across the carburetor barrel; if this plate is firmly closed and cant be manipulated to open with a screwdriver or other tool, you have a stuck choke plate. The plate is not allowing adequate air into the carburetor and, as a result, your engine is running too rich. Try WD-40 or other spray lubricant on the choke plate to free it of gunk that may be affecting its movement. If the plate still wont move or is otherwise not opening and closing freely, have a mechanic replace it.

    3

    Bring your car to a reputable garage and have a mechanic inspect your fuel-injection system. Computer-controlled sensors are responsible for the fuel-injection operation; these sensors can malfunction or simply stop operating, requiring their replacement. The airflow sensor, throttle position sensor and coolant sensor all have a bearing on the fuel/air ratio burned in your engines combustion chambers.

    4

    Ask your mechanic to inspect your vacuum regulator. Fuel is fed into the engine combustion chamber under pressure, which is controlled by this device. The regulator can malfunction and cause fuel pressure to rise beyond specified limits; the regulator can also rupture, allowing fuel into the vacuum line that directly feeds into the chamber. The mechanic will examine the vacuum feed line, test the system with a pressure gauge and check for the presence of fuel. The regulator may need to be replaced.

    5

    Run a pressure test on your vacuum line. You may have a vacuum leak, in which air is escaping from the combustion chambers or vacuum line, causing the engine to run too rich. Vacuum leaks can affect engine performance in other ways, and cannot be repaired in your own driveway. Have a mechanic run a vacuum test on your engine to determine if this is the source of the problem.

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My 1995 Ford Ranger Wont Cold Start

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My 1995 Ford Ranger Wont Cold Start

The 1995 Ford Ranger is a midsize pickup truck. If you are having problems getting your pickup to start in the cold, there are a couple of things that you can check before you have it towed to an auto repair shop. The battery is the most common culprit for a car not to start. If the battery is dead, the motor will not have the electrical current needed to turn over. Fuel, the alternator, and the starter are other issues that you will need to diagnose.

Instructions

    1

    Open your Ford Ranger and try to turn the ignition. If you hear a clicking noise, you will need a certified mechanic to test your alternator or your starter.

    2

    Look to the gauges when you turn the ignition. If the gauges turn on, the problem is not with your battery. Check the Rangers fuel level and then add gas if needed.

    3

    Open the Rangers hood and locate the battery next to the motor. Use a socket wrench or a pair of pliers to loosen the negative (-) terminal from the battery. Clean the terminal with a can of Coke and a wire bristled brush.

    4

    Reattach the terminals to the battery and then restart your truck.

    5

    Jump-start the Ford Ranger with jumper wires and another car. Leave the truck running so the battery can charge.

    6

    Cut the truck off and try to restart the vehicle. Replace the battery if the truck will not restart.

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The Electrical Components of an Engine

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The Electrical Components of an Engine

All vehicles produced from 1996 onwards are considered electronically controlled. This means that the only true mechanical part is the core engine itself. All other aspects are controlled by electronics in one way or another. There are hundreds of electronic components on each engine, but only a few are key components that perform major functions.

Alternator

    The alternator is a key component of the engine and the entire vehicle as it converts the movement of the engine into the electricity the vehicle needs. It converts the movement utilizing a belt that connects to the main pulley of the engine. That belt turns the rotor (a coil of wire wrapped around an iron core). The rotor has 12 volts of power coming form the battery to create a magnetic field. When this rotor spins, the magnetic field creates an electrical current through the three stators (coils of wire along the casing of the alternator). This electricity is then passed through diodes to convert it to direct current and a regulator that senses the vehicles power needs and adjusts the output accordingly.

Starter

    The starter is a high-powered electrical component that cranks the engine at start up. When the ignition key is turned, the gear inside the starter is pushed outward onto the flywheel and spun. This spinning action turns the engine by way of the flywheel spinning. Once the key is released, the gear is retracted into the starter housing, and it stops spinning.

Coil

    The 12 volts that the battery puts out are not nearly enough power to ignite fuel; a vehicle needs at least 10,000 to 15,000 volts to perform this task. This is where the coil comes into play. The ignition coil has a series of copper wire windings around an iron core. This creates a strong magnetic field which takes the 12 volts from the battery and converts them to upwards of 40,000 volts. That voltage is then sent to the spark plugs. There are three types of coils. The older style has one coil that sends power to a distributor then to the plugs. The replacement for that was a more direct system where the power went straight from the coil to the plugs by way of wires. The newest and most efficient is the coil-on-plug. In this system, each individual spark plug has its own coil resting on top of it.

Sensors

    Two of the main sensors in your engine are the camshaft position sensor and the crankshaft position sensor. Both of these sensors perform similar tasks, just with different components. The camshaft opens and closes the intake and exhaust valves, so the computer must know if the camshaft has the right valves opened at certain times. The camshaft position sensor lets the computer know this information. The crankshaft is what regulates the up and down movement of the pistons inside of the cylinder. The computer needs to know the position of the crankshaft, the RPM of the crankshaft and misfire information.The crankshaft position sensor relays this information to the computer.

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How to Install the BMW 1994 318is Head

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The BMW 318is was a compact sporty luxury car that BMW produced from 1992 to 1998. The 1994 model was fitted with the M42B18 engine, which is a four-cylinder 1.8-liter. This engine has a single cylinder head on top of the engine block that covers all four cylinders. The cylinder head is part of the combustion chamber and also contains the poppet valves that open and close the ports in the cylinder head.

Instructions

    1

    Remove the cable from the negative battery cable with a socket wrench. Disconnect the intake and exhaust manifolds. Remove the cover from the ignition coil. Disconnect the electrical wires from the spark plugs and the ignition coil.

    2

    Disconnect the cover for the cylinder head with a socket wrench. Detach the radiator hoses from the engine, and disconnect the crankshaft position sensor from the crankshaft. Detach the thermostat housing for the thermostat, and remove the thermostat from the engine. Disconnect the mounting screws on the cover for the timing case, and remove the cover.

    3

    Turn the crankshaft clockwise by hand until the arrows on the camshaft and crankshaft sprockets face straight up. Disconnect the tensioner for the timing chain with a socket wrench. Remove the mounting bolt on the right side of the upper guide for the timing chain, and disconnect the guide. Detach the timing chain from the camshaft and crankshaft sprockets. Remove the camshaft and crankshaft sprockets.

    4

    Disconnect the mounting bolts from the cylinder head with a socket wrench by loosening the bolts in several passes. Begin from the outside bolts and proceed to the inside bolts. Lift the cylinder head from the crankcase, and remove the cylinder head gasket on the engine block.

    5

    Remove all traces of the gasket from the crankcase and the cylinder head with a gasket scraper. Remove all debris from the new mounting bolts for the cylinder head. Install a new gasket for the cylinder head, using the markings on the gasket as a guide.

    6

    Mount the new cylinder head to the crankcase, and install the new mounting bolts for the cylinder head. Begin tightening the bolts in the center of the cylinder head and proceed outward in a crisscross pattern. Tighten the bolts to 24 foot-pounds with a torque wrench on the first pass. Tighten the mounting bolts an additional 93 degrees with a socket wrench on the second pass. Tighten the mounting bolts another 93 degrees on the third pass.

    7

    Turn the crankshaft clockwise so that its timing mark points straight up, and hold the crankshaft in place with tool 11-2-300. Turn the camshaft clockwise so that its timing mark points straight up, and hold the camshaft in place with tool 11-3-240. Mount camshaft sprockets to the camshaft so the arrows on the camshaft sprockets point straight up.

    8

    Tighten the mounting bolts on the camshaft to between 10 and 12 foot-pounds with a torque wrench. Mount the timing chain onto the sprockets, and mount the upper guide for the timing chain. Fasten the bolt for the timing chain guide with a socket wrench.

    9

    Tap the tensioner housing with a rubber mallet to release the piston from the housing. Place the tensioner in a vise, and push the ends together to engage the snap rings. Place the tensioner into its bore on the crankcase, and tighten the tensioner plug to between 17 and 19 foot-pounds with a torque wrench. Press the rail on the tensioner to release the piston.

    10

    Disconnect the holding tools on the camshaft and crankshaft. Place a new gasket on the upper timing case cover, and fill in any gaps between the gasket and timing case cover with non-hardening sealer.

    11

    Mount the cylinder head cover to the cylinder head. Tighten the 6-mm mounting bolts to between 6 and 7 foot-pounds with a torque wrench. Tighten the 8-mm mounting bolts to between 15 and 17 foot-pounds. Install the thermostat with the vents facing up. Attach the thermostat housing and torque its mounting bolts to between 6 and 7 foot-pounds.

    12

    Install the crankshaft position sensor to the crankshaft, and attach the radiator hose to the crankcase. Replace the valve cover with a socket wrench. Attach the electrical wiring for the ignition coil and spark plugs. Install the ignition coil cover. Install the exhaust and intake manifolds.

    13

    Add coolant and oil as needed. Connect the cable for the battery cable using a socket wrench.

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How to Diagnose a Harley Compensator

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How to Diagnose a Harley Compensator

There is a verified problem with Harley-Davidson Big Twin compensating sprockets. The compensating sprocket buffers torque from the engine and the limitations with this part may be most obvious in newer, big bore engines. A part that was adequate in an 82-cubic-inch engine may not be adequate in a 103-cubic-inch engine. Harley has not issued a recall. The company is, however, selling a reinforced compensator replacement kit, part number 40274-08. The symptoms of a bad compensator are a loud clang at start up, trouble shifting into first or neutral and a sound like gravel in the front of the primary around 2200 RPM. But, the only way to know for sure that you have this problem is to pull the primary cover off and look.

Instructions

    1

    Remove the primary chain case drain plug on the bottom of the chain case under the clutch cover with an Allen socket and a socket wrench. Drain the primary chain case fluid into a pan.

    2

    Inspect the magnetic end of the drain plug for bits of metal. Dredge the drained primary chain case fluid with a magnetic probe. Inspect the probe for bits of metal.

    3

    Remove the five clutch cover screws with an Allen or Torx socket (depending on the year and model of your bike) and a socket wrench. Remove the round clutch cover and gasket. Discard the gasket.

    4

    Remove all four screws in the oval inspection cover with an Allen or Torx socket and a socket wrench. Remove the cover and gasket. Discard the gasket.

    5

    Remove all 12 primary chain case cover screws with an Allen or Torx socket and a socket wrench. Remove the primary chain case cover.

    6

    Remove and discard the primary chain case cover gasket and both primary chain case tower gaskets inside the primary.

    7

    Inspect the compensating sprocket, the clutch, the chain and the chain tensioner for obvious defects or wear.

    8

    Heat the compensating sprocket nut with a heat gun to loosen the nut. Remove the compensating sprocket nut with a hex socket and a breaker bar.

    9

    Remove the spacer, sprocket cover, sliding cam and compensating sprocket. Clean and inspect all components for wear. Replace or repair as needed.

    10

    Inspect the shaft extension for wear before beginning reassembly. Clean the threads on the engine sprocket shaft and the internal threads in the sprocket nut with Loctite 7649 cleaner/primer or equivalent.

    11

    Apply thread locker to the threads on the engine sprocket shaft. Apply engine oil to the underside of the sprocket nut.

    12

    Replace the compensating sprocket, sliding cam, sprocket cover and spacer. Hand tighten the sprocket nut.

    13

    Tighten the sprocket nut to 75 foot-pounds of torque with a hex socket and a torque wrench.

    14

    Install two new tower gaskets and a new primary chain case cover gasket. Replace the primary chain case cover.

    15

    Tighten the primary cover screws to 120 inch-pounds of torque with a Torx or Allen socket and a torque wrench in the exact tightening sequence described in the service manual for your motorcycle.

    16

    Replace the inspection cover with a new inspection cover gasket. Coat the threads of the of the primary drain plug with Teflon paste and replace the drain plug

    17

    Pour primary chain case lubricant into the primary chain case until the lubricant just touches the bottom of the clutch. Replace the clutch cover with a new clutch cover gasket.

    18

    Check for leaks. Road test the motorcycle.

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Painting Over a Powder Coating

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Painting Over a Powder Coating

One of the most common uses of power-based paint is in vehicle restoration. Once a car or truck is sandblasted, the bare metal will begin to rust. Power coating paint is applied to all surfaces to retard the rust and give the restorers plenty of time to complete the needed work. But unless it is done correctly, applying a finish paint job on top of a powder coat can lead to an imperfect surface and a ruined paint job.

Instructions

    1

    Wipe down the entire powder-coated surface with a soft, dry cloth, making sure to completely remove all dust and other blemishes. If needed, use a damp cloth and some mild, soapy water to remove stubborn contaminants. Allow to air dry.

    2

    Sand the entire surface lightly with sandpaper. The goal is to get rid of any peaks or blemishes in the powder coating, without removing it entirely. Make sure to sand every corner and edge evenly. One way to ensure a soft finish is to run the palm of your hand across the surface, checking for irregularities.

    3

    Paint the sanded surface with the paint of your choice. While you can use a paint brush for this step, using a paint sprayer will give much better cosmetic results. A sprayer will also be much faster, especially on larger projects. If you have not previously used a sprayer, you may need some practice in order to properly paint a smooth surface. Use a spare piece of metal or an unwanted item as a practice item. Then press the trigger on the sprayer as you sweep smoothly across the item, over spraying the item on each end in order to ensure there are no gaps or rough edges in the paint.

    4

    Allow the paint to dry, according to the manufacturers suggested timeline. If you are painting a second coat, youll need to lightly sand the surface again, it order to provide the proper surface adhesion for the new layer of paint.

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