What is the difference between in ship 2 stroke main engine and four stroke main engine...........?

Question

What is the difference between in ship 2 stroke main engine and four stroke main engine...........?

Answer 1

The only 2 stoke inboard engine I am aware of was made by GM. They are in my opinion one of the best engines ever made.

They are diesels and there are many series of them starting at one cylinder and going up to twenty four.

I skippered a tug that had 2 of these 149 series, they were 2,400 horsepower each and were V24.

The main difference between these 2 stroke diesels and four stoke units were they have no intake valves, air intake is supplied by gear driven blowers forcing air into ports. These blowers can also have turbo-chargers mounted on them for even more air.

Many commercial trucks used these engines also.

GM made them in 53, 71, 92, and 149 series, larger ones were called EMD (Electric Motor Division) and were used on huge ships and locomotives, the series number being the amount of cubic inches per cylinder.

Unlike what others have answered, they do not have to have oil fuel mix, they have an oil pan (base) just like any four stroke engine.

When the throttle is pushed to full speed, they get up to govened RPM much faster than four stroke engines, although somewhat noisy, they run very smooth and produce a lot of power for their size and weight, quite often produce far more power with less fuel consumption than competitive four stokes.

I have operated and rebuilt the 53, 71 and 149 series of these engines, and they are of very simple design, and very easy to work on.

Answer 2

A two stroke engine has a power stroke every two cycles, giving more power than a 4 cycle.  They run off a mixture of oil and gas, and are noisier and dirtier than a 4 stroke engine.

Answer 3

A 2-stroke needs oil added to the fuel for lubrication, whereas a 4-stroke usually has a proper lubrication system and does not need this. Two-strokes are generally noisier and are smoky and smelly due to burning the oil in the fuel.

Some lawn mowers and dirt bikes are 2-strokes and you know what they are like.

Four strokes generally run much quieter and at slower RPM.

Answer 4

A ships main engine is very different from a small 2 stroke outboard. We are talking about diesels here. 2 or 4 stroke. The main differences are a 2 stroke combines strokes for more power then a 4 stroke of the same size, it is less complex then a 4 stroke and may weigh less then a 4 stroke of the same power.

They do not mix oil and gas like an outboard and 2 stroke diesels have a lubrication system just like a 4 stroke.

Check out these sites.

http://en.wikipedia.org/wiki/W%C3%A4rtsi...

http://people.bath.ac.uk/ccsshb/12cyl/

Answer 5

A two-stroke engine has an intake-compression stroke and a power-exhaust stroke, whereas a four-stroke engine has an intake stroke, a compression stroke, a power stroke, and an exhaust stroke.

2-stroke engines are simpler and sometimes more rugged.  4-stroke engines are more complex, but also much more efficient.

For much more information, including the pictures and diagrams you will need to understand the engine types, do an internet search on "2-stroke engine" and one on "4-stroke engine."

Answer 6

It's too complicated to explain to someone who knows nothing about engines. A four stroke engine has more moving parts, that's all.

Answer 7

2 stroke needs oil and gas mixture. 4 stroke have separate oil and gas.