Silly queries approved

Thanking you,
Yours faithfully
Rx100.7050


Guys,
I need answers in points. Don't give me a lumpsum answer as I will get confused.

>This< will solve your first question... Its a great thread.

Simple mechanical / technical queries
Hi Guys,
Since I do not really like working in my office, my imaginations / thinking unconsciously veers towards something or anything related to biking :P So here is a list of questions I was just having in my mind. Since I do not have any tech background , it is not easy for me to understand the following:
1.

As already answered by saipranav. read the thread. Useful info.


2. More mass means more inertia (if I remember my class X science correctly :P) So if the piston is made heavy it will generate more torque? But then it will also affect engine braking, right? (silly question it seems :P)

It will affect acceleration and rev-ability of the engine. Heavier piston will take longer to accelerate or decelerate, and will give severe vibration when it comes to the end of its stroke and starts moving downward. The piston is generally considered for the following purposes -

- As a moving surface during the combustion process, to transfer the high pressure created by the combustion to usable mechanical energy.

- As a support to the rings, to provide a proper seal, and ensure that the oil and air fuel dont mix.



3. Supposing we have 1 engine of single cylinder & another of multiple cylinders both of same CC, which is likely to produce more power? Now, if there are multiple cylinders for a given CC, then the cylinder size is definitely going to be small. So, does it mean single cylinder will have a bit more of advantage wrt multi-cylinder?



The multi cylinder same capacity engine. For eg, Honda made CBR250 in 88-89 or so, which was 45 bhp from a 4 cylinder 250 cc engine. Thats 62.5cc of each cylinder. Comparably Ninja makes 33 from twin, and the CBR 25-27 from one. ( Not considering compression ratios, bore stroke etc ).

The basic reason is that for a given rotation of the crank, you have more combustion cycles, ( once every 360 degrees for a single, once every 180 degrees for a twin, every 120 degrees for a triple and every 90 degrees for a 4 cylinder ). This improves engine smoothness, the ability to rev higher ( 13,000 rpm for the ninja 250 for eg ), and produce more, smoother power.

1.
I am no expert, and am neither an engineer to answer these as a qualified professional…. And I will try answer these to the best of my logic and try to keep it simple too 
Your question sounds like which of the following will quench more thirst
A 1000ml tiffin box (Flat)
Or a 1000ml water bottle (Tall)

Long Stroke – Needs a long stroke to drain out the water…
Short Stroke – Means smaller stroke required to drain out the water..

There is also a square engine which says same bore stroke size… like a tiffin box where the Length = Breadth
Theoretically the answer to your question is defined in the next set of questions…


2. Yes it will generate more torque… the heavier piston would push the connecting rod … BUT a heavier piston would mean more effort to push the piston up as well so waste of torque!
LONGER the stroke MORE the Piston has to travel...
SHORTER the STROKE slower the piston travels


3.
Does 1000ml of a bottle quenches more thirst or does 2 bottles of 500ml does that better?

Well the answer to it goes back to the second point.
Cons: Two bottles to maintain
Pros: Two smaller pistons to push the crankshaft,
- by alternating the movement you could save some torque.
- By ensuring that the pistons move in same direction you can use a tricked lobsided crankshaft to push the pistons up and thus save a lot of power


The stroke ratio is used to give a certain character to the engine, it all depends on what the engineer wants to use the machines for!

Thanks a lot guys. Infact, I have seen Payeng's post on the engine type before too. It was so easy to understand thereafter about the engine types.

I still have one query. Which type of engine will long last? A short stroke or a long stroke?

A silly question yet again. Piston position in a multi cylinder will never be same, right?