Confuse..!!??

[evil sword]

helow guys

which one make the car faster than other (different car type but same cc) larger bore or stroke

 

[ChefChris]

Your making my head hurt trying to figure out what your asking..

 

[DiS]

yea definetly need to clear up the question, heh

 

[evil sword]

My question is:

Two cars have same engine capacity (I mean same pistons volume) but one of them faster than the other one, what is the main reason of this (ignore the car weight), is it
The height and the inner diameter of the pistons

Hint:
Same volume of two pistons doesn't mean that the height and inner diameter for both pistons are the same

 

[zerocover]

You mean bore vs stroke.
Its an interesting question. But what do you mean by faster.

In theory an engine with bigger bore should be able to breath better as the valves have more side wall clearence. + the bigger bore means better high rpm filling.

Generally longer stroke motors produce more torque and have a lower rev limit. Short stroke motors are the opposite. It comes down to what you like more top end power or low end.

I prefer a motor with higher stroke as it sounds cooler, and I like low end grunt.

 

[evil sword]

well done

ohh thank you zero, i guess you do it, .......are you mechanical engineer

 

[zerocover]

No, im actually a bme. But know alot of stuff so people are always asking me if Im in totally random fields (electrical, mechanical, physics, etc)

The big thing is modern engines have all sorts of tweaks in them to where the cylinder bore vs stroke is not a big deal. What you need to remember is the more the bore the bigger the recipricating mass so there are trade offs. A square engine is usually a pretty good move.

There was a paper published a while ago where the ideal cylender size was pridicted to be at .4l per cylinder so it could fill the most efficently. The amount of air going in to the engine is more important then bore vs stroke if there in a resonable size.

 

[peepsalot]

I'd be interested in reading that paper, hav eany idea where to find it?