Ok, I'm confused about something (gas & displacement)

[Shiv]

Ok so a GSXR 1000cc is a liter bike. 1000 cc = 1000 ml = 1 L

The gas tank holds 18 liters

So the engine only sucks in the fuel 18 times and then it's out? I thought the engine was turning at thousands of RPMs per second? When it's in the phase where it sucks it in (I forget what it's called, Compression?) does it only suck in a fraction of the liter, or does it go the whole liter and one combustion will take you for a while?

I'm gonna go with the former because you'd lose a great deal of energy at stops. That and stop adn go traffic kills gas milage.

So by logic we have that it sucks in a little at a time. Then why is it called a 1000cc? Just because it has the potential to hold a liter at one time? I guess it would be hard trying to compress a liter that's filling a space for a liter, but isn't that the point of compression? Make things that fill a space fill a smaller space.

So how much gas does it really use in one cycle? And why's it called a liter bike if it can't really displace an entire liter at once?

I think I did a crappy job of trying to explain my question but we'll go from here.

[Ninja Geoff]

uhh.... read this:
http://auto.howstuffworks.com/engine6.htm

It's based off the total displacment in 1 cycle.

Fuel consumption is bassed on throttle usage and power. at an idle, fuel is trickleing into the combustion chamber, just enough to keep it moving. And at WOT around 10k RPM, the thing's puking up fuel like a college kid after a 10 hour alcohol binge.

[jmillheiser]

The 1000cc displacement is the total volume of all the engines cylinders combined.

It does not inject 1000cc of fuel at a time.

It only takes a tiny amount of fuel to power a combustion cycle on a 4 stroke engine. The Fuel injector only sprays a tiny amount of gas into the intake at a time. When you open the throttle more air flows into the engine and the injection system in turn injects more fuel to build more power.

A carburetor works on a slightly different principle but to the same effect. With a carb the suction of the engines cylinders literally pulls the fuel through the jets and into the intake

[CNF2002]

A cylinder doesn't hold a bunch of fuel while it fires. Fuel in its liquid state does not even combust. Your engine vaporizes the fuel as it enters the combustion chamber, and it is the vapor that ignites when it hits the spark, thus increasing compression in the chamber and thrusting your piston up.

A tiny, tiny bit of fuel for each cylinder firing each time.

Gas mileage drops in stop/go traffic because the engine requires more RPMs to accelerate, and while stopping/stopped your engine is producing power and using gas but not getting you anywhere...which is why you have bad gas mileage (because you are not travelling as many miles for the amount of power your engine is producing) whereas at around 55mph you are using your mile vs. power/gas most efficiently.

[Shiv]

You sure it vaporizes it? I'm pretty sure that the fuel while under pressure would be very volatile and would have no problem combusting in a liquid state.

[Ninja Geoff]

When the fuel/air mixture is let into the cylinder, it's a very fine mist at that point. And it may not go completely boom like it would normally do under spark, but enough energy would be used up so the spark wouldn't make a typical boom. Also, this doesn't ALWAYS happen when using the wrong grade of fuel, just now and then, ecspecially under hard acceleration.

[CNF2002]

Someone with more knowledge may pipe in, but I'm pretty sure it has to vaporize the fuel in the cylinder. Compressed liquid gas may ignite (I dunno) but I imagine if you had fuel in two different states within the cylinder they would burn at different rates.

[Shiv]

But why would it be two different states?

Just because it's getting sprayed into the cylinder doesn't mean it's a gas.

And once it was combusted, it goes out the exhaust.

[SuperRookie]

In addition...let's not forget that the fuel/air mixture is compressed FIRST...this compression also raises the temperature of it...THEN the spark triggers the combustion, which is more of a "controlled burning" than an "explosion"...

Anyway...just google "four stroke engine basics"

.02c

[ZooTech]

But why would it be two different states?

Just because it's getting sprayed into the cylinder doesn't mean it's a gas.

And once it was combusted, it goes out the exhaust.

The injectors atomize the fuel, they don't convert it to a gas. Atomization is necessary for a quick and even burn, otherwise you end up with unspent fuel and cylinder hot spots.