defects and solutions
Although I joined in February and winter would have to say goodbye, Romania seems to no longer escape the cold and snow. We know the joy of snow is small, but we can not say the same about adults, especially for those behind the wheel. Snow this year he gave great head beats drivers all over the country, but many of them acknowledged that their cars are equipped with summer tires, that is inappropriate for this season.
Summer or winter?
To drive the vehicle in areas with temperature differences is something that definitely affects the general condition of it, especially if the tires. Some tires are designed specifically for warm season, when the asphalt is hot for winter time we find special tires. In these lines we will discuss the differences between winter tires and summer tires.
Summer tires
The gum may have different effects when they come into contact with a hot ground. Summer tires are composed of a rubber softer and more elastic over the winter and are specially designed for use at temperatures above 7 degrees Celsius. The good behavior on dry and wet asphalt viscosity of the compound due, but not recommended on roads covered with snow or ice. Are able to withstand high temperatures during summer and become very rigid at low temperatures, so that significantly affect adherence.
These tires also Fri especially designed grooves that provide better traction on rainy days.
Although these tires, through their flexibility, offers an easier and more enjoyable
handling the steering wheel are easily worn away. So get ready to throw a set of tires
faster than one summer or winter all season.
Winter Tires
Just as the name suggests, these tires are designed to be used easily at temperatures below 7 degrees Celsius. These tires have a specific model encrusted. Small grooves intersect with each other more, pushing the outside pushing snow or water. The material is thicker than usual and is made of a compound based on silicon.
Because the components that keep their properties at low temperatures and multiple notches on the tread, these tires have a greater grip on snow or ice. Winter tires tend to be slightly more noisy than summer, but some newer models seem to have removed this problem.
All Season
For those doubtful or not to change tires twice a year there and the type of tire all season. These tires are specially designed for use throughout the year, all seasons, in all conditions. Combines qualities of the tires for summer and winter, but in extreme conditions is, tires all season are lower than summer or winter on land or on snow.
Ignition settings
The installation of ignition are made the following adjustments:
- Adjusting ignition advance;
- Regulating the opening contacts ruptorului (platinelor);
- Adjusting distances between electrodes spark plugs;
- Disruptions in vending synchronization with two pairs of contacts.
Adjust Ignition advance.
In practical terms, advance the ignition is the most important engine tuning.
Advance is determined by the time he is the primary current interruption by opening contacts ruptorului.
Advance is required primarily for the "explosion" is not an instantaneous combustion.
To have power and good efficiency, must obtain the maximum pressure when the piston begins to descend.
To this end, the burning must be started before the PMS, that spark has to occur in advance of this punct.Avansul is measured in degrees traveled by manetonul question. The advance is not measured in millimeters of stroke of the piston, as it produces large errors.
The process of piston does not depend on crankshaft position, but the total size of the race, the long rods to stroke and dezaxarea shafts.
Adjust ignition advance can be done in six ways:
- By setting the distributor body in the correct position: regulating "the advance price;
- Screw micrometers, known as "octane selector.
- The button operated from the dashboard (rarely applied);
- By changing the opening contacts ruptorului;
- The automatic centrifugal;
- By adjusting device by depression.
The first four are manual adjustments, the last two advance automatically adjusted.
All adjustments to advance (with the exception of centrifugal) are turning to the axis of the plateau contacts ruptorului distributor causing the opening
them.
Adjust opening contacts ruptorului is so;
- Camshaft ruptorului be brought to the position of the hammer reaches the maximum opening of contacts, this can be done either hit a little power button automatic or slowly turning the handle or pushing a car after I put the gearbox lever in direct engagement or pulling the fan belt;
- After this, the distance between contacts will adjust the two screws acting on the fixed contact support, one being screw fixation and one for the adjustment screw:
- After loosening screw, screw for adjusting the work until we get a distance between the contacts of 0,3-0,5 mm;
- Distance measurement is made with a calibrated slide (Lera) or failing that can use a piece of paper folded in four;
- By measuring the collar screw fixation and distance control again.
Adjust the distance between electrode spark plugs
The engines ignition system powered by battery through a distributor, it is recommended that the distance between electrodes is 0,5-0,8 mm plugs.
Interim changes the distance between the electrodes can be useful in some cases, for example, if the battery is discharged and dynamic defect, sparks may become so weak that the engine start to stop irregular, likely to stop.
In such cases, if shorten the distance to about 0.3 mm in all spark plugs, the resistance between electrodes is reduced, sparks will be produced regularly and we could go ahead.
Adjust distance bending the electrode mass is not to achieve the central electrode as the easiest of the impactor to cause breakage of the insulator.
Some engines can work load even with 0.1-0.2 mm distance between electrodes, but can not operate at idle because the spark is too short.
Synchronizing contacts open
It is necessary to dispensers with two or three pairs of contacts.
The operation is done with a timing device and is very important for all engine cylinders to work with the same ignition advance.
Manual
All cars have device for regulating the advance price. This is done with a necklace that secures the distributor body position required for collecting a screw.
Micrometric screw octane selector is at about 80% of cars modern, but the button on the dashboard with which we can adjust without stopping the advance
car is not even installed on 20% of the car, although it is very practical.
However the advance of hand is necessary to reduce the advance driving when gas is not found suitable, or when for some reason produce strong pink.
Optimal adjustment
The advance is good if it produces a set "snap" very low when the engine working in full load, the direct engagement, at a speed of 30-40km / h.
Adjusting in this way can not produce engines however loony boost advance. The case is very rare and may occur when:
- Ratio is very low (under 5), for example, by doubling the cylinder liner;
- Octane gasoline used is much higher octane than the engine.
Optimal adjustment of the advance is always with a certain approximation.
Automatically advance
Adjust the advance is necessary to obtain optimal advance at all speeds and different loads being placed on the engine.
Centrifugal automatic regulator.
Engine speed range from 500 to 5000 rpm, so the average piston speed varies from 1 to 10. Meanwhile, the combustion rate varies only from 10 to 30m / s or about 40 to 100 km / h.
It is understood that in these circumstances requires a device for automatic switching to advance to ensure the most convenient, appropriate engine speed. This automatic device advance as speed, is found in shelf contacts. Its main elements are two difficulties that can rotate each around a shaft and are attracted by two small spring steel spiral.
The distributor camshaft can be rotated to the axis of command and is trained by two bolts ordered two weights.
When speed increases, the weights away and rotate the distributor camshaft making it into a more advanced control over the axis. So are breaking early and sparks are produced with great advance.
Advance the best not only depend on engine speed, but also the shape of the combustion chamber, the compression ratio, cylinder head etc. material.
Therefore, every type of engine is an optimum advance curve is set at the factory building in the tests that are the test bed in the middle of pregnancy, gradually increasing speed.
There are large differences between the optimal advance side-valve engines and the valve head.
The development of ignition
This can be necessary if he:
- To repair a loose necklace attachment to the socket of the distributor;
- To mount a new distributor.
Put the ignition point is to put the distributor and records straight.
For it is sufficient that when one piston is at TDC, the "explosion" ruptorului contacts are about to be opened, and files relate to spark plug ignition engine in order that.
So in advance we need to know:
- Direction of rotation of the distributor shaft;
- Size head start;
- Order a flash.
Advance knowledge of the power (between 0 5grade) has great importance for early operation.
Any engine are parts (signs) that facilitate the development. These signs may be:
- A line on fan belt wheel control, which is when the table next to an arrow mark the position of the crankcase distribution No.1 piston at TDC;
- A landmark on the flywheel visible through a window of the housing clutch, also showed that the piston 1 at TDC.
If two lines are drawn is likely that the first direction of rotation indicates the emergence Scinteii crankshaft position at startup (fixed deposit).
Signs of the stalemate on the wheel and fan belt on the cover distribution are less accurate than those of the flywheel, but more easily visible.
Advance the development of the workshop does not require a high accuracy as the final adjustment is made after the sound of pink to test on the road.
Therefore, it tends to widespread use of signs on the pulleys and cover distribution and to desfinţarea parts of the flywheel.
Removing-fitting distribution
Whenever it is practical to disassemble a distributor be removed from the engine with the advance adjustment plate and sheets (preferably numbered). In so doing, avoid another entry to the ignition point after reinstalling the distributor to the engine.
Axis of the distributor can not be wrong because the channel coupling on the end of the lower wedge is eccentric.
If the cut would be in the middle, the rotor could be placed in the wrong position by half a rotation and engine would not start because all the sparks would occur in the late racing exhaust cylinders.
Inductor is not recommended to be fitted on the engine because the increase
Inductor is not recommended to mount the engine as it increases the danger of damage due to vibration.
Yet to be closer to the dealer for the central plug to be as short as possible, for example, 20-40cm long.
If the central sheet is long sparks are worse.
Identification of the induction coil terminals
If he does not know how to made connections to a coil which has three small blocks, it will do so:
- Is denoted by terminals A, B, C, at random;
- A link to the first bridge terminal of the battery lead (to work at a voltage of 2V);
- Link to hammer screw terminal B;
- Are a series of breaks, noting that the central plug sparks occur and how long they are;
- Repeat the operation with terminals A and C;
- Then Csi B terminals;
- If one of the three combined does not appear sparks, coil is the type of variable;
- In this case the common terminal to test the small sparks and the sparks will prove no link to the thread that comes from the ignition key;
- Common terminal to test with large and small sparks will connect the wire going to hammer;
- Common terminal sample with large sparks and sparks probe without cotactul will connect automatically start;
- If the central plug sparks occur at all three possible links, means that inductor winding is the type of aid;
- In this case is to link two terminals successively how many children to an element of 2V and read the ammeter a current to each of the three possible combinations;
- Common terminal current small and medium must be connected with wire coming from the ignition key;
- Common terminal high current and medium link to hammer;
- Common terminal high and low current link to the power automatically.
It will use these samples only a voltage of 2V to avoid burning any of Variators (resistance protection).
Influence on ignition
The flame started from the spark is initially very low and relatively cold. If the environment in the plug is too cold, the flame is extinguished and combustion ceases.
In this regard, here is a simple and enlightening experience: the engine in perfect condition, with plugs a little too hot, adjusted idle until we get a uniform and went very slowly. Immediately after it replaced all spark plugs with others colder, without
other change. Then start the engine and see that not working at all at idle.
It follows that, although adjustments are perfect, the mixture no longer lights up, because sparks occurring in a cold environment. Reinstall the spark plugs warm, without other changes, the engine operates normally again.
Voltage required to produce Scinteii depends on:
- Distance between electrodes spark plugs;
- Open throttle;
- Ambient temperature in which the spark occurs;
- Dosage fuel mixture;
- Air humidity (hygrometric state);
- Compression ratio;
- Plug electrode shape and material;
- Losses through insulation.
Polarity Scinteii
Has some influence on the functioning and quality Scinteii plugs.
Polarity Scinteii depends on some characteristics of constructive induction coil.
To determine the optimal installation will do the following:
- Use a normal writing pen with graphite lã virgem sharp, it is necessary to attempt to make the dark, the engine is hot;
- Pull the plug from a plug and a net so that the free distance above and below the pen tip to be 1-2mm;
- Start the engine and see in the dark as shown sparks are produced;
- If sparks visible on the pencil into plug means that polarity Scinteii is good;
- If the pencil sparks more visible towards the plugs, be reversed links the two terminals of primary windings of the induction coil.
With this assembly production Scinteii is better served as first pulsation of the secondary electron discharge starts from the central electrode which is warmer than the electrode mass.
Disadvantages: central electrode wear out faster.
If the inductor has high reserves of power relations can be reversed, and in this case the electrodes will wear more evenly and more slowly, so the plug will increase sustainability.
AX. DEFINITIONS. CLASSIFICATION.
MATERIALS. TECHNOLOGY
Machinery bearing trees are meant to support other elements contributing to the transmission of rotational motion.
They are cinematic touch with other elements, which transmit rotary motion.
The trees have straight or linear geometric longitudinal axis straight common axis of rotation.
Trees were the main function of transmitting rotary motion and a twisting moment. Usually, trees are called so as to twisting and bending. Desori main request is turning.
The main criterion for classification trees it is therefore just the type of application that are subject to.
Once this criterion is:
- Trees torsion-torsion-considered request only or mainly in torsion;
- Compound-shafts subjected to torsional and bending.
Fig trees or the camshafts crankshafts fig.b contribute to the transformation of rotational motion in the translational motion.
Materials. The main material is steel shafts are built. Are used, in particular, following steel grades: OL37, OL42, OL50, OL60, OT45, OT50, OT60, OLC25, OLC30, OLC45. May be different brands of alloy steel întrebuinţează as: AUT 40; 42Cr 10; 41MoCr11; Ni15 etc. 13Cr. Quality irons are used when trees are not strongly request. When necessary other physical properties using other metal materials (brass, bronze) or minerals (Textolite, plastics, etc..)
Information Technology. Usually. Trees run by turning the metal profiles, which is turning the whole length. Area support bearings are processed very neatly by grinding, polishing, etc..
Trees, can also be run by forging, from all of the semi-metal. Operation of forging blank prepared for processing by cutting. Medium-sized trees running by casting or by welding, and are subject to mechanical processing.
These elements are built with full section or circular section. When built with circular section material is better used.
Section is full but frequently used because it runs better.
Main parts of trees are:
- Spindles;
- Areas of riding;
- Intermediate sections.
Channels until needed fixing parts on the shaft, you should be enforced in the same plane and with the same width as much as possible.
