Valves- All you need to know about Valves

Archive for November, 2009

Diesel engine principles are pretty straight forward for the experienced mechanic but what about regular everyday people who have never taken the time to find out more about a diesel engine and how it works?

I am going to explain in layman terms the basic principles of a diesel engine.

What is the difference between a gasoline engine and a diesel engine?

The first thing you should know is a gasoline engine and a diesel engine are totally different. A gasoline engine is constructed much lighter than the heavier built diesel engine. The gasoline engine runs on a air and fuel mixture combined with a high energy spark that is timed to ignite inside each engine cylinder at the precise time creating power and torque turning force which drives your vehicle.

A diesel engine uses high compression intake air that is compressed into a very small space inside each cylinder causing extreme heat. This is called heat of compression which ignites a very fine high pressure mist of diesel fuel that is injected into each cylinder at the exact time.

So you now know that a gasoline engine needs a high energy spark to run while a diesel uses heat of compression. The four stroke principle in all engines run on four strokes or four cycles, both these terms mean the same.

Here is how the four stroke diesel engine operates. The four strokes are intake, compression, power and exhaust.

The pistons, valves and injectors work together in each cylinder in a set sequence over and over.

Intake stroke. Intake Valves in the cylinder head open allowing pressurized air to enter each cylinder while the piston is traveling downward. The pressurized air supply is made possible by the turbocharger which pushes air into the intake system giving the diesel engine a boost of air to keep up with instantaneous injection of fuel.

Compression stroke. When the piston starts to move upward the valves close which traps the intake air in the cylinder and allows compression to take place. The heat of compression is reached when the piston reaches the top of the cylinder, the diesel fuel is then injected into the cylinder at the precise time.

Power stroke. After injection takes place an explosion occurs in the cylinder because of the combination of heat and atomized diesel fuel. This causes the piston to be forced downward which produces torque and the horsepower required from a typical diesel engine.

Exhaust stroke. After the power stroke the piston moves upward once again while the exhaust valves open allowing the previously ignited gases to escape to the atmosphere out the exhaust system.

As mentioned before each cylinder goes through this exact sequence over and over in a set firing order. For instance, a 6 cylinder diesel engine has a firing order 1 5 3 6 2 4 This is the order that each cylinder goes by, following the 4 strokes mentioned above.

This sequence has been engineered to allow the diesel engine to run smoothly with no imbalance.

Here is some diesel engine trivia on high performance diesel engines. Fuel passes through the injector at speeds of nearly 1500 miles per hour, as fast as a jet plane at top speed. Fuel is injected into the combustion chamber in less than 1.5 milliseconds, the same time it takes for a camera flash to go off.

The minimum amount of fuel injected into a diesel engine is one cubic millimeter, about the same volume as the head of a pin. Volkswagen has developed a one liter diesel powered car that got 100 kilometers out of .89 liter of fuel, 60 miles on less than one quart of fuel.

There is much to learn about diesel engines and a ton of information online. If you have ever considered buying a vehicle with a diesel engine you have my blessing.

The extra cost will be to your benefit, so I recommend finding out more about diesel engines before you decide which one to choose.

I hope you have found this information on diesel engines helpful.

John Whelan
http://www.articlesbase.com/trucks-articles/diesel-engine-principles-for-beginners-105588.html

One of the hottest commodities in the pickup industry is the Honda Ridgeline. It has swept almost all truck of the year awards given out by major motor shows. This may not be a surprise, after all, the giant of a company that is Honda has been known for introducing to the public innovative and technologically advanced vehicles.

It would not surprise a driver if he found himself enjoying the full sized pickup from the moment he set his eyes on it. The beauty of this car does not end in its looks. While the design of the car is modern and is an eye candy, the manufacturers did not just stop there, of course. This monster of a car boasts of a unit-body full frame structure. This, in itself, is an innovation which takes this car on top of its class. The design brought to life by engineering geniuses of the company gives the car a very rigid structure. It also has front and rear end crumple zones in addition to having a rigid frame thereby increasing the safety of both driver and passengers in case of crashes. It is also dubbed as the pickup that will most likely not roll over.

Another reason for the fuss about this car is its In-bed Trunk. The Ridgeline tonneau is also another innovation which gives the user a storage area below the pickup bed, a convenient solution to storing supplies safe and dry.

Performance-wise, the vehicle is also one of the best in the market today. Its powerhouse is a 3.5 litre, 24 valve, SOHC VTEC V6 engine capable of giving the driver of up to 247 units of horsepower and a torque of 245 lb. ft. While this may not sound much compared to other models with bigger engines, but it is enough to power the pickup very well. All this power is transferred on all four tires of the truck, but during dry road driving, it is a two wheel drive vehicle. Once the going gets tough, the Variable Torque Management (VTM4) system goes to work and sends power to the tire needing traction. It is done so through its five-speed automatic with fluid cooler transmission.

In addition to that the vehicle has a Vehicle Stability Assist which keeps drivers from getting into troubles. The system automatically compensates for both oversteer or understeer. It has independent suspensions for both front and rear giving the driver the confidence to tackle hard off road conditions.

Joe Thompson
http://www.articlesbase.com/cars-articles/awardwining-pickup-from-honda-the-ridgeline-90838.html

After I am done using my air compressor, I open the valve at the bottom to let all the pressure and moisture out so that it does not rust. Once all the pressure had been released, is it better to store it with the valve closed or open?

The first thing to do would to bleed the tank. The bleeder valve, in most cases, is located on the bottom of the tank. More than likely, you’ll see rusty water drain from it as it releases the air in the tank. When you’ve accomplished this task, close the bleeder valve & refill the tank with air to capacity. Your compressor is now ready for storing. The importance of not leaving your compressor’s valve open is because, if left open, this would allow constant air to gain entry into the tank, thus, allowing the inner walls of the tank to severely oxidize…..

What is the manual button used for on a honeywell mid position valve, is it for when your draining the central heating system?

you can use for draining and filling of the system, its also an emergency way to give you both heating and hot water in case of failure..