# Can someone explain what "Litre's of displacement" is?

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Can someone explain what "Litre's of displacement" is and what it does to your car?
(ie. i4 1.7L engine, or i4 2.0L engine)

Ki2AY

the displacement of the car is just the sum of the bore and stroke of all the cylinders in total. bore being the size of the cylinder width, and stroke the distance from the top point of the piston, to the most bottom point.

basically, u can conclude from this that the bigger the cylinder is, the bigger the piston it will be housing (or it should atleast unless u want some piston slap), and the more the piston can travel up n down, the better it can work through the cycles (processes the mixture more).

more displacement = easier power (and lots more too)

Inygknok

more power? does that mean more HP? what kinda power?

Ki2AY

Ok, the more accurate description is that displacement is the total volume of of all your cylinders combined. The formula would be:

PI*(bore/2)^2 * stroke = volume (for one cylinder)

volume * (# of cylinders) = total displacement

The larger your displacement, the more fuel and air you can stuff into each cylinder. The more fuel/air, the more energy you get out of each cylinder. You see where this is going.

Yes, it means more power but without specifics it is hard to say how much more power. There are some down sides to increasing the displacement on a motor. Decreased cylinder wall thickness, higher rotational inertia, and others.

Hope this helps clear things up.

theman352001

more power means more horsepower and more torque, simple.

as for the more displacement u have, the heavier the engine will be and the more strain it has cuz it has to move heavier equipment.

Inygknok

ok i understand now, bigger = power.... but my question is... what advatages will a car wid 2.0L lancer es engine with 120hp do against a 1.7 civic es 127 hp. i have another thread up, and most people said the civic will win... becuz it has 7 extra hp and just a tid bit lighter.. but what i dont understand is what advantage would the lancer have if it has 0.3L more?

Ki2AY

THe lancer would probably have a HP of aroung 125 to 130, while weighing a tad more than before . but no more the a couple of pounds.

Coffin Type R

The 2.0L Lancer will most likely have more torque than the Civi so it may be a bit quicker off the line. But as mentioned, the Civi is lighter so there may be no difference. Why don't you just race the two (at an established 1/4 mile track) and find out who will win?

The extra displacement gives the Lancer more room for improvement. As seen in this example, bigger does not always equal more power. But if you were to modify both motors, you should be able to squeeze out more HP in the end with the Lancer motor if it was designed well.

Other factors come into play when your talking about stock, and I am assuming daily-driver, vehicles. How are they each maintained? How have they been driven? Milage? We could also get into transmissions and gear ratios but I'm betting thats a bit too technical.

There is a lot to a motor than just displacement. Theres balance, flow, compression, etc... that all effect power. Then there is the rest of the driveline and its efficiencies. You could hook up a higher horsepower motor to a crappy drivetrain and still have a lower horse motor beat you.

So don't go bragging about your displacement #s with your friends. Unless of course your in the 400CI + range. Sorry, that's 6.6L + for you metric folk. And even then........

theman352001

i am not bragging about anything.. its just that when i bought my lancer, both my uncle and the dealer said that the 2.0 es lancer is faster then the 1.7 ex civic.. and my friend owns a ex civic with a 1.7 engine, and i asked him the same question, he said his stock civic would burn mines.. all i wanted to know is which side was true and understand why and how.

Ki2AY

Well, the easiest way would be to look up the stock specs for your car and your friend's car and compare. Question solved. I would have provided links but you did not mention years.

Glad you got it solved though.

theman352001

Oh my goodness...why must it all be spelled out in black and white. A dealer is going to tell you anything to get the sale...and apparently he sold you.

Go to the track and race your friend. There are so many variables that make an impact that it is difficult to pin down which would win and why based on numbers only. 7 HP difference is not much, but it is a bit more when that 7 HP is on a lighter car. What if your friend weighs less than you do? What if you forgot you had your Croquet set in the trunk?

The 2.0L has no advantage over the 1.7L other than .3L more displacement.

This questioning is getting annoying because it is simply about, "Is my car faster than his?"
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BavarianWheels

2002 LANCER ES 4DR I4 2.0L
2002 CIVIC EX 2DR COUPE I4 1.7L

(BOTH STOCK AND AUTOMATIC)

Ki2AY

actually, as i said before, im just trying to understand this.. i dont giva damn if his car is faster than mines, thats what i thought anyways... i just dont understand this litre of displacement.. so stop asumming shit and quit it with your nasty attitude man... why must you always critisize people, this is a forum, if you have nothing good to say or if the question is annoying the shit outta you bav, than ****! dont post anything.. gosh, simple as that.. your older, im the kiddo.. u should know that by now.

Ki2AY

That's not what this post implies...
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BavarianWheels

yes it does!!! its in the same category.. as i said, im trying to understand "why and how" which leads to litre of displacement. thx anywayz.

Ki2AY

ok look, this cant get any easier. in EXTREMELY SIMPLE TERMS, without any complicated explanations, bigger displacement is better.

but how an engine is produced, meaning how efficient it is n how well it can flow, will determine its performance. u could have 2 2.0L inline-4 engines in the exact same car, with the exact same weight and transmission gears, BUT if one engine is built better than the other one, it will win, just because of superior construction.

the better the engine is built, the more powerfull it will be (only if its built better for performance though, if its built better for economical reasons then screw it, but u SHOULD get the point im trying to explain).

displacement is simply as i said in my first post, the circumference of ALL the cylinders and the riding distance of the pistons in all the cylinders. thats it.

Inygknok

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BavarianWheels

POST #9 BAV.
:screwy: :thumbs:

im still waiting for a picture of ur "powered by honda" sticky on ur beemer. :hi:

Ki2AY

arite, thx Inygknok, i already understand it...

Ki2AY

In simple terms, the engine displacement is the volume of the cylinder swept by one stroke. In other words it is the length of pistion travel multiplied by the cross sectional area of the piston. This volume is multiplied by the number of cylinders. The ramifications of this is the larger displacement, the more air you can move through the engine thus more fuel.

In the case of a 2.0L vs a 1.7L, there is not enough differences in displacement to be worth fussing over concerning the engine performance. There are many other variables involved (there have been engineering texts written on them) governing engine performance as well as things such as transmission gearing (this actually determines how much of the torque gets to the driving wheels). Most dealer sals folks have no clue what the specifications actually mean

Drive the cars then buy the one you actually like

tbaxleyjr

BIGGER IS NOT BETTER!

cinqyg

there is alot of diffrence from a 1.7 - a 2.0, of the same engine series will normally give you a bit more power, there is also potential for a reduction in weight in some cases.

cinqyg

ill give u one phrase which u didnt seem to read at all (this is called "reading over the fine print").

phrase 1) There is no replacement for cubic displacement. im sure we can all agree on that one for obvious reasons.

phrase 2) ok, this aint really a phrase, but just do as i say. go read every single post in here thats mine and read every single word. u will see how i state that its not always better, but the bigger displacement engines do have an advantage.

Inygknok

Interms of displacement i think one thing that solves this issue are rotary engines. There is an optermum displacment.

i think we have to define our objectives to have this discusion.

cinqyg

Well i think his question wasn't about who's car was faster as in a race and crap. I think he was asking more of a which engine is more powerful type of question. Either the higher horses, 7. Or the higher displacement, .3. And i dont think he was asking it to know which one could beat which, but to figure out the relation between displacement and engine power so that he could himself relate that to the horsepower of the other car. He probably thought 'Okay his car has more horses but my car's displacement is higher. What does displacement really mean though?' And by asking us he now knows how displacement affects his car. But if we are to look closely, we could see how this thread is already starting to change course into a which car is faster post. And people keep explaining the theory of displacement though im sure that he already understood it the first 3 times it was explained. And Bav did kinda just jump in and start running at the mouth about "you guys wanna know which is faster!!!" when that wasn't the intention at all. I even think Ki2AY tried to express his first post so that people weren't to think that this was a which is faster post to begin with. Just my :2cents:

VMJYogi

I was going to stay out of this but since I was one of the original responders.....

Evidence A: Ki2AY's 3rd post in this thread.

This does hint / infer at wanting to know which would be faster.

Evidence B: A post or few later.

Further infers there was a "which car would beat which" underlying question.

To his defense, he does state that he wanted to know who was correct and why. But part of that statement is "which side was true" and that means which car is faster.

So I think it a bit unfair that people are blasting those of us who thought this was a "which car is faster" thread. Yes, he had the intention of wanting to know WHY?? and we explained that to him. But lets be fair, he DID want to know which car would be faster.

And don't even get me started on those who answered the question later without even seeing what was replyed before. They must like restating what was already posted. :doh:

theman352001

THANK YOU SO MUCH.

Ki2AY

"EVIDENCE A" i only asked that question to lead to my 2nd question which was my real intentions. i cant just jumpt over the facts you know.. i wanted to show you guys where i am going with this....
true i did ask who would win, BUT ONLY TO UNDERSTAND WHY.. it was more of a why then a who question.. sorry, i dont blame ya.

"EVIDENCE B" same as A, but... i know i should'nt have used the word "Faster" but my explanation for this is because, i didnt know what word to use cause i didnt know what the "L" does... do you understand?

god, this forum is starting to get so strict... links, post being edited, people jumping to conclusions, people with bad attitude, people with no manners, and now i have to worry about what i type because im afraid people will critisize me....

Ki2AY

It is unfortunate, but we must interpret your thoughts as you write them.

The web is kind of quirky that way. :banghead:
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BavarianWheels