Why Can't Bike Engines Run on Diesel?

Some bikes do run on diesel. There are quite a plenty of reasons why
most bikes run on petrol/gasoline and not on diesel. Today in this article I will discuss why can’t bike engines run on diesel? 

Why can’t bike engines run on a diesel engine?

Why Can’t Bike Engines Run on Diesel?

Diesel engines are also called compression ignition engines. The compression of diesel is much more than that of gasoline(petrol). First talk about the compression ignition engine. Below, is a diagram of a compression ignition engine- 

Diesel Engine

The famous German inventor, Rudolf Christian Karl Diesel first introduces the diesel engine, which is called the compression engine. The Density of Petroleum diesel is about 0.85 kg/l – about 15-20% higher than the density of gasoline.

Diesel is much less flammable than gasoline. In a car, it takes intense pressure to ignite diesel.

Compression Ignition Engine– 

The diesel engine is an internal combustion engine in which air is compressed to a sufficiently high temperature to ignite diesel. Fuel is injected into the cylinder, where the combustion and expansion acute a piston.

The compression temperature of the air is about 500-600^oc. The compression pressure needs to be high to have efficient combustion take place and avoid any ignition lag. This high temperature of the air is the reason behind auto ignition and we don’t need any spark plug for the ignition.

Read more- What is the 4-stroke diesel engine? 

Diesel fuel is injected at extreme pressure, high temperature, and sub-micron droplet size. The diesel is injected through the injector at a high temperature of oxygen-rich pressurized air.

Disadvantages of using the diesel engine in a bike- 

There are a lot of disadvantages to using a diesel engine in a bike. I’ll explain. The
points are as follows.

Diesel engines are expensive-

The basic working of a diesel engine is a bit harsher than petrol engines. They have a higher compression ratio too which means they have to use more heavy metal to withstand the pressure and compression. They also vibrate and sound more. The types of equipment fitted onto diesel engines to make all the vibrations, sounds, etc minimal are quite expensive which in turn makes the engine quite expensive. Still the NVH (noise vibration and harshness )level remains much more than in petrol engines.

Diesel engines weigh much more-

due to all the extra types of equipment fitted and too much more metal because of reasons explained in the last point^, the weight of the engine increases. The extra fuel efficiency that the diesel engines come with would become useless because the weight would rather decrease the fuel efficiency.

Bikes don’t need that much torque-

The power and torque that a diesel engine comes with are actually useless for a bike. As bikes are not that heavy, petrol engines serve great while giving great acceleration and no power gets useless.

Diesel engines are not very happy –

You can simply revive a good petrol engine to around 6500 rpm before shifting. Whereas, diesel engines get quite vocal even past 5000 rpm.