[west]

And did you guys notice some 2 stroke engines die if they were over heated. This happens in first gen sunny. it dies after 30 kms of continous driving wonder why??

[RX135]

Which one is more efficient 2 or 4 to the fuel consumed??

4 strokes are more efficient. They allow complete more burning and more controlled overlap of intake charge with exhaust gases.

and why are deisel engines heavier??

You answered it yourself

[superavi]

The stroke is the movement of the piston in the cylinder.

A two stroke engine has a compression stroke and a power stroke. The chamber is not sealed and the fuel ignites and a power stroke is created.

A four stroke engine has the four strokes of the pressure charge, ignition, power stroke and release of gases.

Correct me if I'm wrong but that's why power out put of two strokes is higher, and at lower rpm in comparison to the fourstrokers.

As far as diesel not requiring spark plugs, its because at similar compressions diesel ignites, whereas petrol requires an ignition spark.

However diesel at specified compression ratios still requires an ambient temperature to burn. Which is why diesel engines have heaters for the engine.
This sometimes causes problems for diesel engines at higher altitudes because of very low temperature and you find all taxis in the north and north east running mostly petrol engines.

Btw any information on the trucks that are used in the North. I mean army trucks. Any information on how they function? Do they run on petrol as the temperature is pretty low in those areas.

[Gordon]

Correct me if I'm wrong but that's why power out put of two strokes is higher, and at lower rpm in comparison to the fourstrokers.

By the time a four stroke engine completes one cycle [one power stroke], the two stroke engine will have already completed two cycles [two power strokes]. So more power.

[Shan2nu]

2 STROKE ENGINE : As you can see, the sprk is ignited every time the piston is at TDC (Top Dead Center).



4 STROKE ENGINE : Here the spark is ignited every alternate TDC. Thats bcos the 2nd TDC is used to push the burnt gasses outside (exhaust stroke).



Shan2nu

[Technocrat]

Whoa Shantanu Excellant Pic

[Vulken Auto]

Originally Posted by RX135

4 strokes are more efficient.

you might be wrong, 2 stroke more efficient system, leave the mileage im talking abt power developed to fuel consumed.

approx

60% of energy converted in to power in 4
around 80 % energy converted into power in 2

btw: found this in my mech lab 8 years ago , so couldnt say precisely but quite sure.

[RX135]

Originally Posted by Vulken Auto

60% of energy converted in to power in 4
around 80 % energy converted into power in 2
btw: found this in my mech lab 8 years ago , so couldnt say precisely but quite sure.

Why do you say that? When I studied 10-11 years back, 4 strokes were more efficient

[Vulken Auto]

Originally Posted by RX135

Why do you say that? When I studied 10-11 years back, 4 strokes were more efficient

I dont want to search now, but some one please throw some light here.
May be books have changed in those 3 years which made 2 strokes more efficient
Ok we get only one stroke power in 4 , so the remaining 3 are idle hence lot of time for energy to disipate from flywheel and blah blah....some one help me out here please ........

[RX135]

Originally Posted by Vulken Auto

I dont want to search now, but some one please throw some light here. May be books have changed in those 3 years which made 2 strokes more efficient Ok fly wheels takes the energy for 4s right for 3 strokes and help me out here........

Fly wheel does not take energy, it stores it, so that it can be used later. It is like a capacitor in electronic circuit. 4 strokes are more efficient, since it operates with valves which clearly separate intake and exhaust strokes (Though at high speeds, there is overlap). Which means cleaner combustion, lesser CO, more power per power stroke. Real life example is all 4 stroke bikes vs 2 stroke bikes. My RX gives me 35+, where as Pulsars etc. give around 50.

[Vulken Auto]

please support your facts so that I can learn if Im wrong.

haah you theory is very good but might not be true.

[RX135]

Please refer to my post below. Is there anything over and above that? And no, it is not my theory. This is what I have learnt What problems do you see in this theory?

[Vulken Auto]

nothin dude I dont believe it, the 4 stroke has lot of moving parts which disipate energy, that mileage theory might be false.

I know pulsar gives 50 but im how much power it gives for fuel burnt will get the answer, not how many miles it covers.

[RX135]

4 strokes are more complicated than 2 strokes and have more moving components, which consume some power. But it is 4 stroke which produces more power per stroke for given reasons.

Damn it! I need to stay away from T-BHP for few days, looks like I am starting debate in every thread I post.

[Vulken Auto]

I will be happy if I clear my doubt today and go to bed. Ok now I have to search for some evidence to base my theory. I will be back with some light.

You are funny man its not arguing its clearing doubts. arguments will be supported by facts