[sokath]

So apparently they're making new Mazdas with something called a wankel engine, which basically is a three-sided object rotated inside some sort of oval... because of it's three sided nature, you can get the injection, explosion, and exhaust parts of a normal piston-based engine, in one stroke (as opposed to three)... it's kind of a neat concept, the new mazdas have three of these which equates to about 9 cylinders on a regular car, it's pretty neat

http://www.monito.com/wankel/rce.html

check it out

S./

[Adrien]

The Wankel engine used to be the great fashion in the 70's: NSU first with their Speeder and Ro-80 (what an incredible car), then Citroen with the GS Birotor.

The problem was the cost, oil consumption, and maintenance, and soon they fell in disgrace, killing NSU.

Mazda is the only one to perpetuate the tradition since then, with its Cosmo and RX-x models.

[sokath]

Y'see I know nothing, nor care nothing about cars... for some reason... so therefore would not have known that this technology was over 30 years old. My buddy told me about it today, and I just assumed it was new, but thought it was rather interesting nonetheless.

Heh.

Sure shows how much I know..

S./

[Adrien]

Sorry, i didn't mean to sound like i was pointing out you were wrong..

I was just adding a little thing to your post and link.

Anyway, the new Mazda is "da car". (<== wishes he just won at the lottery)

[sokath]

Sorry, i didn't mean to sound like i was pointing out you were wrong..

don't worry, that's not how I took it... I was just pointing out how wrong I was.

S./

[Jon]

I'll just point out then that a car has four strokes.
Injection, Compression, Explosion, Exhaust.
But I know very little about cars as well...

[sokath]

isn't diesel the only type of vehicle that uses compression?

S./

[Adrien]

I'd say they all use four strokes..

Anyway, our dear Trabant were simpler and used two strokes engine!

[Siberian Fox]

isn't diesel the only type of vehicle that uses compression?

I think Diesels are different in that they rely on compression to ignite the fuel. But then I also know nothing about cars...

[Jon]

Not quite, but I see where you're coming from.
A typical 4-stroke engine works like this:
On the first downstroke the fuel is injected into the cylinder.
On the first upstroke the fuel is compressed. At this point a diesel and petrol differ slightly.
In order to get the explosion in a petrol engine, an ignition source is required - this is the purpose of the spark plug. This then creates an explosion, pushing the piston down.
The piston then travels back up, ejecting the fumes resulting from the explosion.

The diesel works much the same except it needs no external source to provide it with ignition. The compression of the fuel is enough to cause the explosion.
This also helps to explain certain other differences between the two engines. For example, if a diesel looses the battery (for whatever reason) whilst the engine is running, it will not cut out. However, if a petrol engine looses the battery, the engine will cut as there is no external ignition source.

That enough to get you up to speed on the internal combustion engine?
Wow your friends with this new found knowledge.

And in the time I took to write that, two people had replied!!!

[sokath]

The worst part is, all my friends already have that knowledge... so there's no real wowing them... sadly...

S./

[Jon]

How about Turbochargers and Superchargers?

[Adrien]

I know that they compress the air differently (exhaust gas/engine power) but that's all, i have no idea of what it concretely does.

[Jon]

They don't compress the air differently per se - they just compress more of it. The fuel is not there to provide power - all it does is provide a source to make the air inside the cylinder expand very quickly. The more air you can fit into an engine the more power is produced from the resulting expansion.
A Supercharger is essentially a fan that is rotated by the engine, so as the crankshaft (the shaft the pistons drive) rotates faster the more air is sucked in.
A Turbocharger (or Turbo) is a fan linked to a turbine that sits in the exhaust. As the exhaust gases are expelled from the cylinders faster, the turbine spins the fan faster increasing the air intake.

The main problem with a Turbocharger is lag time... those brief moments between putting your foot on the accelerator and the turbine spinning up to suck more air in. A Supercharger does not have this problem as it is directly connected to the engine allowing instant power. However, (and this is where I start to get hazy on the subject) the turbine can turn faster than the crankshaft (which can normally get to about 9000 revs before it simlpy won't go any further and breaks), thus producing more power.

Also, new turbos have almost no lag whatsoever (how they do that I don't know) so the need for superchargers is quickly dissapating.

[Ocker]

Yes, the new rotisserie engine in the RX-8 is called the RENESIS, it is the latest rotary engine.

Turbochargers and Superchargers, or Turbos (Turbocharger) and Blowers (Supercharger) have pros and cons for different applications.

Turbos are also know as 'hairdryers' and 'snails' (due to their snail shape).

One, as Jon said, Turbos have 'lag', whereas with a blower, you will feel power instantly.
You can also have more than 1 turbo, This is known as 'Twin Turbo'.

Turbos are powered from exhaust gases, whereas a blower is from the crank.

Also, you can't beat the sound of a blown (supercharged) V8

There is 2 types of Turbos, 'Blow-Through and 'Draw-Through'

The basics of a Turbocharger:
Turbos are a type of air pump used to force more air into an engine with the goal of ultimately providing more grunt, and it differs from a crank-driven supercharger because it's powered by exhaust gases.

The idea is that, in a N/A (Naturally Aspirated, no forced air), a whole whack of the energy generated by the internal combustion process is lost out the tailpipe. Turbos are designed to harness this lost energy.

Turbos have 2 main sections, the back half - the turbine - and the front half - called a compressor. Both parts consist of a bladed wheel which spins within a housing. The front and back halves are joined by a shaft, supported by bearings.

Instead of sending the gas straight out the tailpipe, the exhaust manifold directs it into the turbine which is then caused to turn at very high speeds.

The turbine then drives the compressor, which sucks in fresh air, compresses it and send it on its way to the inlet manifold.

The pressure created by the compressor is called 'boost' and is measure in pounds per square inch (PSI) or barometic pressure (bar).
This measurement is also in addition to existing atmospheric pressure, which varies and effects to some degree the performcane of your car.



Phew - I am VERY bored -
There are 2 types of Turbos, 'Blow-Through and 'Draw-Through', this has to do with the carburettor.
If your nice I may explain the difference, aswell as the supercharger if I find myself so bored again.

[Adrien]

While we're talking of Renesis, it has been elected "Best international engine of the year" at the Engine Expo of Stuttgart.

In the categories: the RENESIS has been elected "Best new engine of 2003" and "Best engine of the 2,5 to 3 L. category", beating Volkswagen's V10 TDI and BMW M3's six cylinders.