MULTI FUEL ENGINE

Multi Fuel Engine:-

The main aim of our project is to run a two stock engine from multi fuel.

i.e

1. LPG

2.Petrol

Fuel are always not available , so that we use multi fuel engine, because we have multi fuel option to run a engine. In US army all the vehicles are multi fuel engine.

The two-stroke engine consists of only three mobile parts: Piston, connecting rod and crankshaft.The first two-stroke engine was a gas engine invented and built by Etienne Lenoir in 1860.  A two-stroke diesel engine was built by Dugald Clark in 1878

A multifuel engine is constructed so that its compression ratio permits firing the highest octane fuel of the various accepted alternative fuels. A strengthening of the engine is necessary in order to meet these higher demands. Multifuel engines sometimes have switch settings that are set manually to take different octanes, or types, of fuel.

The Parts Required for Multi Fuel Engine are:-

1.      2 Stock Eninge

2.      LPG

3.      Petrol

4.      Vapourizor Kit

5.      Stand

6.      Pipes

7.      Petrol Container

8.      Regulator

9.      Cylinder

10.  Swiths

Mode of operation of the Two-Stroke engine
1st Stroke
At the point where the spark plug fires, fuel and air in the cylinder have been compressed, and when the spark plug fires the mixture ignites.
The resulting forces drives the piston downward. As the piston moves downward, it is compressing the air/fuel mixture in the crankcase.
As the piston approaches the bottom of its stroke, the exhaust port is uncovered. The pressure in the cylinder drives most of the exhaust gases (but not all) out of cylinder.
As the piston finally bottoms out, the intake port is uncovered. The piston's movement has pressurized the mixture in the crankcase, so it rushes into the cylinder, displacing the remaining exhaust gases and filling the cylinder with a fresh charge of fuel.


2nd stroke
Now the momentum in the crankshaft starts driving the piston back toward the spark plug for the compression stroke.
As the air/fuel mixture in the piston is compressed, a vacuum is created in the crankcase. This vacuum opens the reed valve and sucks air/fuel/oil in from the carburetor. Once the piston makes it to the end of the compression stroke, the spark plug fires again to repeat the cycle. 

There is a third type of engine,­ known as a two-stroke engine, that is commonly found in lower-power applications. Some of the devices that might have a two-stroke engine include:

·         Lawn and garden equipment (chain saws, leaf blowers, trimmers)

·         Dirt bikes

·         Mopeds

·         Jet skis

·         Small outboard motors

·         Radio-controlled model planes

In this article, you'll learn all about the two-stroke engine: how it works, why it might be used and what ­makes it different from regular car and diesel engines.

Two-stroke Basics

This is what a two-stroke engine looks like:

You find two-stroke engines in such devices as chain saws and jet skis because two-stroke engines have three important advantages over four-stroke engines:

·         Two-stroke engines do not have valves, which simplifies their construction and lowers their weight.

·         Two-stroke engines fire once every revolution, while four-stroke engines fire once every other revolution. This gives two-stroke engines a significant power boost.

·         Two-stroke engines can work in any orientation, which can be important in something like a chainsaw. A standard four-stroke engine may have problems with oil flow unless it is upright, and solving this problem can add complexity to the engine.

These advantages make two-stroke engines lighter, simpler and less expensive to manufacture. Two-stroke engines also have the potential to pack about twice the power into the same space because there are twice as many power strokes per revolution. The combination of light weight and twice the power gives two-stroke engines a great power-to-weight ratio compared to many four-stroke engine designs.

You don't normally see two-stroke engines in cars, however. That's because two-stroke engines have a couple of significant disadvantages that will make more sense once we look at how it operates.

The Two-stroke Cycle

The following animation shows a two-stroke engine in action. You can compare this animation to the animations in the car engine and diesel engine articles to see the differences. The biggest difference to notice when comparing figures is that the spark-plug fires once every revolution in a two-stroke engine.

This figure shows a typical cross flow design. You can see that two-stroke engines are ingenious little devices that overlap operations in order to reduce the part count.

Sparks Fly

You can understand a two-stroke engine by watching each part of the cycle. Start with the point where thespark plug fires. Fuel and air in the cylinder have been compressed, and when the spark plug fires the mixture ignites. The resulting explosiondrives the piston downward. Note that as the piston moves downward, it is compressing the air/fuel mixture in the crankcase. As the piston approaches the bottom of its stroke, the exhaust port is uncovered. Thepressure in the cylinder drives most of the exhaust gases out of cylinder, as shown here:

The Compression Stroke

Now the momentum in the crankshaft starts driving the piston back toward the spark plug for thecompression stroke. As the air/fuel mixture in the piston is compressed, a vacuum is created in the crankcase. This vacuum opens the reed valve and sucks air/fuel/oil in from the carburetor.

Once the piston makes it to the end of the compression stroke, the spark plug fires again to repeat the cycle. It's called a two-stoke engine because there is a compression stroke and then a combustion stroke. In a four-stroke engine, there are separate intake, compression, combustion and exhaust strokes.

You can see that the piston is really doing three different things in a two-stroke engine:

·         On one side of the piston is the combustion chamber, where the piston is compressing the air/fuel mixture and capturing the energy released by the ignition of the fuel.

·         On the other side of the piston is the crankcase, where the piston is creating a vacuum to suck in air/fuel from the carburetor through the reed valve and then pressurizing the crankcase so that air/fuel is forced into the combustion chamber.

·         Meanwhile, the sides of the piston are acting like valves, covering and uncovering the intake and exhaust ports drilled into the side of the cylinder wall.

It's really pretty neat to see the piston doing so many different things! That's what makes two-stroke engines so simple and lightweight.

If you have ever used a two-stroke engine, you know that you have to mix special two-stroke oil in with the gasoline. Now that you understand the two-stroke cycle you can see why. In a four-stroke engine, the crankcase is completely separate from the combustion chamber, so you can fill the crankcase with heavy oil to lubricate the crankshaft bearings, the bearings on either end of the piston's connecting rod and the cylinder wall. In a two-stroke engine, on the other hand, the crankcase is serving as a pressurization chamber to force air/fuel into the cylinder, so it can't hold a thick oil. Instead, you mix oil in with the gas to lubricate the crankshaft, connecting rod and cylinder walls. If you forget to mix in the oil, the engine isn't going to last very long!