How Engines Work
How do Engines work? From this page you can navigate through various different type of engines and how they work –
[important]When i talk about fuel efficiency i am referring to the percentage of fuel that is used to power the vehicle. For example, if a four stroke engine is approximately 40% efficient then 60% of the fuels energy is wasted through heat loss, friction, wind resistance etc.[/important]
The Jet Engine is very fuel inefficient yet has high power, hence the reason that it is used on aircraft to take people from one continent to another at 550mph. It also has very few moving parts which means it is a very stable machine and mechanical failures are very rare.
The Four Stroke Engine has a lot less power than a jet engine but is a lot more efficient (approx 40% efficient), which is why you will find it in most of our cars. It does however have a lot more moving parts than a jet engine, mechanical failures are fairly common.
The Diesel Engine is used in many transport related jobs, the reason for this is that is has a lot of torque (can pull heavy loads) and is also more efficient than the four stroke engine (up to 50%), this means that transport companies save a lot of money on fuel costs compared to using a four stroke engine. It has less moving parts than a four stroke engine and works on simpler principles, mechanical failures are rare.
The Two Stroke Engine is very light and powerful for its size (high power to weight ratio), yet is less efficient than a diesel or four stroke engine. For this reason it is used on many types of recreational vehicles, from small farm machinery, trials bikes & remote controlled vehicles.
The Steam Engine can generate quite a lot of power but is very inefficient, however, those that were most recently built less than fifty years ago were approaching fuel efficiencies of 40-50%, unfortunately for the steam engine it also requires a large boiler to be carried around with it filled with water. It also needs a large bunker to store its coal. The old type steam engines that can be seen on trains in the westerns require a lot of maintenance, usually oiling. All modern engines have automatic oiling systems that are internal and require very little maintenance, apart from maybe changing the oil and oil filter once a year.
The Stirling Engine was developed shortly after the steam engine, this was because the science of metallurgy was only in its infancy when the steam engine was invented, this resulted in many boiler explosions and often the deaths of the men working near the steam engine, this was due to the rivets being made of poor quality metals. For that reason it was deemed necessary to create a low pressure type steam engine, the result was the stirling engine. Unfortunately for the stirling engine it works on a low pressure system. For a stirling to output the same horsepower as a typical four stroke engine found in modern cars it would have to be the size of the car itself. It also needs to be preheated before it will run properly instead of simply turning a key – not very practical. The Toy version of one of these though is possibly the coolest machine i have ever seen, they run off the heat of your hand!!!