Archive for June, 2009
Diesel Engine Principles For Beginners
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.
About the writer:nbsp;nbsp;John Whelan is a certified Heavy Duty Mechanic with 30 years experience and enjoys sharing tips and resources on school buses and other related mechanical systems. Check out his Website for free tips photos and information.
Curious If Great Deals On Vehicles Really Exist At Government Auctions? The Truth May Surprise You!
It is true that auctions can be an excellent source for new and used vehicles at low prices. It is also true finding these deals can be difficult and most government agencies do their best to receive fair market value for these vehicles.
There are three main government agencies that deal with vehicle auctions. These agencies are the treasury department the US marshal service and the general service administration GSA. The GSA predominantly sells vehicles that have been used by the park service and the post office. These vehicles have high mileage but most are in great shape because maintenance was conducted like clockwork by the government.
The best chance of finding new vehicles at auctions is through the treasury department and the US marshal service. The treasury department will often receive vehicles that have been repossessed due to back taxes. The best chance of finding brand new sports cars is through the US marshal service. The US marshal service seizes cars from drug raids.
Police auctions are another great source for seized vehicles. When attending a police auction you must bring a photo id. You must always keep your assigned number with you when bidding and you should always carefully read the rules of the auction. You never want to lose a bid because you did not follow a simple rule.
Always be mindful of the condition of the vehicles. Some of the vehicles at police auctions have been sitting at an impound lot for years before finally going to auction. A good rule of thumb to keep in mind is never pay more than the blue book trade in value. The trade in value is typically 3000 to 4000 below market value.
Never ignore the fine print at government auctions. Experts in this field know how to spot a good deal and they also know how to maneuver through all the government red tape. When you purchase a vehicle from a government auction be sure to fill out Form SF97. Form SF97 is a certificate to obtain title. This must be filled out in order to register your vehicle after purchase.
All liens or any other encumbrances on the title are cleared by the government agency unless otherwise stated. It is important to ask and find out what the government agencies title policy is when attending the auction.
One strategy that will help you obtain good vehicles at low prices is to focus on cars that have body problems but have great engines. Some of the vehicles sold through the GSA have body problems but the engines are in great shape. Not as many people are interested in these vehicles.
One car dealer I know of would buy filthy cars at car auctions and then simply take them to the car wash. Once they were clean he would be able to sell them for 500 to 1000 more. Never underestimate the power emotions play in a bidding war.
Many people claim that no deals exist at these auctions because all of the big car dealers attend these auctions. Many think how could I possibly compete against these big boys. Well the truth is that these dealers need to buy low and sell high to make a profit.
Do not let these car dealers intimidate you. They are looking to make a profit and you are looking to find a good deal on a vehicle for yourself. You can still get a vehicle at these auctions below market price even if you are bidding against dealers. Remember you have the advantage against the dealers.
Before buying any vehicle at auctions you must do proper research. Before going to any government auction bring cash and predetermine how much money you are willing to spend and what type of vehicles you want to focus on. A spending cap is critical. There is nothing worse than getting caught in a heated bidding war and paying more than you planned.
At any government auction you should always inquire about the buyers premium. This is the additional amount you will need to pay once you have won the vehicle. The buyers premium is typically five to ten percent of the purchase price. You should incorporate this into your maximum allowable bid.
When purchasing vehicles from the government you are buying them in as is condition. When possible inspect the vehicle yourself. Inspection times can vary from one hour to two days. Many government auctions have a preview date before the auction where you can ask questions and inspect vehicles. When possible you should run a Carfax vehicle history report.
When doing research on the web regarding government auctions never buy anything that claims to have the secret ways of getting great deals at government auctions. You can find this information anywhere on the net. Only deal with websites that give you valuable information regarding where auctions take place in your area. These websites can save you a lot of time and give you immediate access to auction locations.
About the writer: http://www.localcarauctions.info
Compare Van Insurance: Is It Better To Compare Or Not?
When you need commercial van insurance for your business its always better to compare van insurance online with a good comparison website. The reason for this is that one quote just isn’t enough if your looking to save money on your van insurance policy. They are many websites that compare van insurance in the UK but not all of them can find you cheaper quotes.
The saving you can make by taking a bit of time comparing van insurance can go into the hundreds. If you haven’t got the time get someone to do it for you like a employee or your other half. Sites that contain advertising from insures are good but this can result in only one single quote giving you no choice at all. Look for website that puts you first and answers most of your questions on the site before you buy the policy.
If your just starting out in business and you have just bought your first van get it insured properly by a respectable company. This can save you allot of hassle in the future as the company should go thought the policy with you so you understand what your covered for in the event of an accident.
All insurance companies and policies differ from van insurance to car insurance but they are some things that count across the board with all insurers. Some things are the drivers age the age of the van and how many year noclaims bonus are have. This all help you find cheap insurance quote when you compare van insurance online.
About the writer:nbsp;nbsp;You can
compare van insurance 15 different insurers. For free advice and a cheap
van
insurance quote I invite you to
http://www.vaninsurancebritain.co.uk
