Showing posts with label engine. Show all posts
Showing posts with label engine. Show all posts
Wednesday, April 10, 2013
How to Produce More Engine Power
Car manufacturers are constantly playing with all of the following variables to make an engine more powerful and/or more fuel efficient.
1. Increase displacement - More displacement means more power because you can burn more gas during each revolution of the engine. You can increase displacement by making the cylinders bigger or by adding more cylinders. Twelve cylinders seems to be the practical limit.
2. Increase the compression ratio - Higher compression ratios produce more power, up to a point. The more you compress the air/fuel mixture, however, the more likely it is to spontaneously burst into flame (before the spark plug ignites it). Higher-octane gasolines prevent this sort of early combustion. That is why high-performance cars generally need high-octane gasoline -- their engines are using higher compression ratios to get more power.
3. Stuff more into each cylinder - If you can cram more air (and therefore fuel) into a cylinder of a given size, you can get more power from the cylinder (in the same way that you would by increasing the size of the cylinder). Turbochargers and superchargers pressurize the incoming air to effectively cram more air into a cylinder. SeeHow Turbochargers Work for details.
4. Cool the incoming air - Compressing air raises its temperature. However, you would like to have the coolest air possible in the cylinder because the hotter the air is, the less it will expand when combustion takes place. Therefore, many turbocharged and supercharged cars have an intercooler. An intercooler is a special radiator through which the compressed air passes to cool it off before it enters the cylinder. See How Car Cooling Systems Work for details.
5. Let air come in more easily - As a piston moves down in the intake stroke, air resistance can rob power from the engine. Air resistance can be lessened dramatically by putting two intake valves in each cylinder. Some newer cars are also using polished intake manifolds to eliminate air resistance there. Bigger air filters can also improve air flow.
6. Let exhaust exit more easily - If air resistance makes it hard for exhaust to exit a cylinder, it robs the engine of power. Air resistance can be lessened by adding a second exhaust valve to each cylinder (a car with two intake and two exhaust valves has four valves per cylinder, which improves performance -- when you hear a car ad tell you the car has four cylinders and 16 valves, what the ad is saying is that the engine has four valves per cylinder). If the exhaust pipe is too small or the muffler has a lot of air resistance, this can cause back-pressure, which has the same effect. High-performance exhaust systems use headers, big tail pipes and free-flowing mufflers to eliminate back-pressure in the exhaust system. When you hear that a car has "dual exhaust," the goal is to improve the flow of exhaust by having two exhaust pipes instead of one.
7. Make everything lighter - Lightweight parts help the engine perform better. Each time a piston changes direction, it uses up energy to stop the travel in one direction and start it in another. The lighter the piston, the less energy it takes.
8. Inject the fuel - Fuel injection allows very precise metering of fuel to each cylinder. This improves performance and fuel economy.
Wednesday, March 27, 2013
Noise and Vibration Optimization of a Gasoline Engine Peugeot Citroen
The block, head and transmission were constructed of predominantly low-order hexahedral elements, whilst the ancillaries were modelled using a combination of high order tetrahedral, shell and beam elements wherever appropriate. The technical approach detailed here is representative of Ricardo’s standard methods applied to the analysis of the powertrain to optimise its noise and vibration characteristics.
Modal Analysis, Dynamic Load Calculation, The excitation loads acting on the engine were calculated using ENGDYN. ENGDYN is used to predict the time-domain response of the 3-dimensional vibration of the coupled crank train and cylinder block system with non-linear oilfilms at each of the main journal bearings.
Saturday, March 23, 2013
1999 Mitsubishi Mirage 1 5L Engine Service Manuals
ENGINE ASSEMBLY INSTALLATION Install the engine assembly, checking that the cables, hoses, and harness connectors are not pinched. ENGINE MOUNT BRACKET INSTALLATION 1. Place a garage jack against the engine oil pan with a piece of wood in between, and install the engine mount bracket while adjusting the position of the engine. 2. Support the engine with the garage jack. 3. Remove the chain block and support the engine assembly with the special tool. HIGH-PRESSURE FUEL HOSE INSTALLATION 1. Apply a small amount of new engine oil to the O-ring.
Caution Do not let any engine oil get into the fuel rail. 2. While turning the fuel high-pressure hose to the right and left, install it to the fuel rail, while being careful not to damage the O-ring. After installing, check that the hose turns smoothly. 3. If the hose does not turn smoothly, the O-ring is probably being pinched. Disconnect the high-pressure fuel hose and check the O-ring for damage. After this, re-insert the fuel rail and check that the hose turns smoothly.
Caution Do not let any engine oil get into the fuel rail. 2. While turning the fuel high-pressure hose to the right and left, install it to the fuel rail, while being careful not to damage the O-ring. After installing, check that the hose turns smoothly. 3. If the hose does not turn smoothly, the O-ring is probably being pinched. Disconnect the high-pressure fuel hose and check the O-ring for damage. After this, re-insert the fuel rail and check that the hose turns smoothly.
Get from here to download 1999 Mitsubishi Mirage 1,5L Engine Service Manuals
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