Diesel Engine in Royal Enfield.

Diesel Engine In Royal Enfield.

Straightly, the truth is firstly diesel engines were fitted in used RE bullets by local mechanics due to the problem of low mileage then on seeing the success of these Motorcycles RE also decided to make diesel engines.

Royal Enfield in India was the only manufacturer that has built a diesel motorcycle in mass production in the year of 1980s .An industrial diesel was installed in the frame of the British-based Royal Enfield. However, due to pollution laws, this bike is no longer produced. Royal Enfield started manufacturing Bullets with the diesel engine and named it the Taurus. The Taurus was available with an electric starter in 1993 The Royal Enfield Diesel Taurus was coupled with a 325 cc, 4 Stroke Air cooled Diesel engine. It delivered maximum power of 6.50 HP @ 3600 RPM and maximum torque of 15.00 Nm @ 2500 RPM. Its engine is mated with a 4 speed gear transmission. The bike is capable to give back an economy up to 72 kmpl.

A Saharanpur based company named Sooraj Automobiles produce diesel motorcycles with Royal Enfield gear box fitted with Lombardini 325cc diesel engine. The company advertised fuel efficiency of 80kmpl, and most of them are still in running condition.

So, yes the diesel engines were actually built by RE.

Why the production of Cast Iron engines in Royal enfield Has stopped?

Although I have discussed many points related different engines and their advantages and disadvantages over one another, now the question is why CI engines have stopped.

Well the answer to this question, there is not only one reason but many which are as follows:-

1-The right side position of gears and left side position of brakes tends to new people walk away from bullets.

2- The Indian motorcycle market started growing and people started getting many choices in lesser price ranges.

3- The maintenance of bullets a bit on higher side.

4- The problems eg- oil leakage, gasket problems etc. were the headache in price sensitive market.
5- Pollution norms also a point which could not be neglected.

Actually the fact is at that time too, bullet was only for the hobbyist ones but they are very few, thus sales was less and this all because of the design, weight, cost,  maintenance and riding ergonomics(placement of gears and brakes) of the motorcycle.

In Indian market as fuel pricing go high and higher the competition launches more economical motorcycles at cheaper prices, in 2007 RE was about to buried but then they introduced UCE engines and from then to till now you go to buy a RE you have to face a long waiting period.

UCE Engine in Royal Enfield.

UCE Engine in Royal Enfield bullet Series.

So, the question is what is an UCE engine?

Well the answer is UCE (Unit Construction Engine) as the name specified this engine having a single unit unlikely Cast Iron and AVL engines series.

In this engine all three stages combined together and hence the losses decrease as i have discussed in my previous blog the losses of power in Cast Iron and AVL engines due to 3 stages was near about 33% while in UCE engines it goes down to 20% transmission losses in this the power generates t crank is 19.8hp and at sprocket near about 16hp.

So, the advantages of UCE engines over Cast iron and AVL engines are as follows:-

1-Transmission losses became lower hence power increment.

2-Lesser maintenance, due to single unit.

3-Better mileage, company claim its twin spark(UCE) engines having better mileage and power.

4-  No manual decompression, so starting this engine is just like any other motorcycle engine.

5. This engine has a longer life in different conditions. Why?

     Just check out these important facts about latest UCE engine.

The points to complain about this engine are as follows:-

1- NO MORE THUMPING SOUND as we used to have in Cast Iron.
2-More Vibrations compared to Cast Iron, AVL engines have higher vibrations than CI but lesser than UCE.
3- This is the point which vary from person to person which is looks, the old bullets had a bulky look, personally my favorite is the Cast Iron one.

The Cast Iron Engine Bullet Electra.

AVL Engine Bullet.

UCE Engine Bullet Electra.

AVL engines in Royal Enfield.

AVL Engine in Royal Enfield bullets.

AVL stands for Anstalt für Verbrennungskraftmaschinen (German Institute for Combustion Engines),so this is an Austrian-based automotive consulting firm as well as an independent research institute. It is the largest privately owned company for the development of powertrain systems with internal combustion engines. So the engines build on there platforms known as AVL engines.

So what is different in these AvL's engines.

The AVL is an all aluminum, lean burning engine where as the earlier Cast iron engines were havier. AVL engines have geared oil pump, which is more durable and less prone to oil pump problems, and has a capacity to pump the oil 40% more efficiently than the conventional Plunger pump of Cast iron engine.

The AVL engines have oil seals on the Valve Guides of the engine, which ensure the leak proof performance of the engine as compared to the classic Cast iron engines, which have the long history of oil leaks.

The compression ratio of AVL engines is more then Cast iron engines, hence it produces more power, although the company claims that both the engines produces same 18 bhp of power.

The advantages on these AVL's engines over CI engines were:-

1-Less heating of the engine because of aalloy material.

2-Increased durability.

3-Less maintenance required due to less heating, proper pumping and leakage proof function.

4-less engine oil consumption.

5-Less Fuel consumption hence better mileage.

The major negative thing about these engines  was there was no exactly same Thumping sound as it used to be in Cast Iron engine because of aluminium construction of AVL engine, thus it loose interest of a huge bulletiers.

Similarly as Cast Iron engine this AVL engine also divided into 3 parts:-

1- Combustion cylinder Assembly. 

2- Gears Assembly. 

3- Clutch Assembly.

The Cast Iron Engine in Royal Enfield.

The Cast Iron Engine in Royal Enfield bullet Series.

So, the question is what is the cast iron engine?

Well the answer is so clear as Cast iron is a metal type and Royal enfield used to made their engines from casted iron so they known as the Cast iron engines.

In this engine the whole assembly of the engine was divided into 3 parts are as follows:-

1)- The Internal Combustion Engine(piston and head and the area having crankshaft).

 

2)- The clutch assembly

and

3)- The Gear Assembly.

Due to this the engine became heavy and look big but the major disadvantage of this engine was the power loss. This engine generates near 19 horse power at the Crank but at the sprocket it gives lesser than 13 horse power because of the loss of power at crank to clutch and gearbox. However, if i talk about the advantages of this engine over UCE(Unit Construction Engine) are not as few as disadvantages. As

 

1- The vibration In this is very less compare to use.

 

2- Ride stability is also somewhere better due to less vibrating machine.

 

3- The Thump, because of heavier crank and steel engine and this is the point which every one know about bullet the voice or noise or sound whatever you want to say you can say it because different people having different opinion for that but the thing which is common in everyone's is that the bullet is a MAN thing it is tough heavy and muscle. specially the older once The C.I bullets.

 

4- One of the most discuss able point is the gear on the older cast iron engines was on the right side with a neutral finder lever so no matter in which gear you are just one press to that lever and you will be in neutral just like that, the brakes on  the left made it a quite difficult to ride for new bullet riders but once you got familiar with that you enjoy your ride in all conditions. Back then this is the point due to this people say the bullets is not for everyone and only for The Man.