Would the multiple ignition points mean the fuel/air mix can be ignited at top dead centre, as opposed to 2 or 3 degrees before?
Also, is the increase in efficieny compared with fuel injected engines or carburettors?

Auditor #9 wrote:

Mixes fuel and air before ignition like in petrol which it says is cleaner for soot unlike the diesel with the big dirty black smoke sometimes.

Multiple ignition points - what's the reason for that? Must be tricky to engineer that...


There's an avatar for somebody

Should we offer it to 905? I still feel a bit mean about having taken away his Dancing Hitler.

AfricanDave wrote:

Would the multiple ignition points mean the fuel/air mix can be ignited at top dead centre, as opposed to 2 or 3 degrees before?
Also, is the increase in efficieny compared with fuel injected engines or carburettors?

Do you mean degrees in angle or heat and do you know much about the relative efficiencies of carburettors versus injection? If they were to burn more fuel more evenly would they need to inject less? I like the analogy of hitting the pedals of your bike with a hammer

cactus flower wrote:

Should we offer it to 905? I still feel a bit mean about having taken away his Dancing Hitler.

The one at carbibles is good too

I mean in degrees in angle.
I wouldn't know any figures off hand but as far as I'm aware injection is slightly more efficient than carburettor.

I've been meaning to put a thread together on the differences between diesel and petrol too - from distillation to combustion. Diesel is less distilled (like Scotch) isn't it? so it needs pressurization ... wouldn't petrol explode better and more evenly using the same technology - pressurization?

With the angle of fuel injection do you see some way the angle would have a bearing on the efficiency or not? Isn't it as EVM says above - it's about burning less fuel at lower temperatures... How would the angle have an effect?

What I meant about the angle thing is that petrol engines generally ignite the fuel/air mix at around 2 or 3 degrees (the angle of the crank shaft) before the piston reaches top dead centre.
As far as I know, the reason for this is because the fuel/air can take a short amount of time to ignite so it starts the ignition process shortly before it is needed.

I'm not too sure about the distillation processes involved with petrol and diesel but as far as I know you are right in saying that diesel is less refined than petrol.
The main reason diesel engines are more efficient than petrol is because they revolve slower.
The combustion of diesel provides more torque than petrol which allows the same kind of power output at lower revs.
Traditional diesel engines don't like going too far over 3000rpm, whereas petrol engines are generally happy enough up to around 6/7000rpm.

If a standard 4-cylinder diesel engine is revolving at say 2,000rpm then it burns a set amount of fuel 4,000 times every minute.
If a petrol engine providing the same power output must revolve at say 4,000 (these figures are plucked right out of my imagination so don't start giving out about the relative difference between petrol and diesel engine revolution speeds) then it burns the same set amount of fuel 8,000 times per minute.

Quote :

The new TLA: HCCI - could mean 20% more efficiency from your ICE. According to CNN today, automakers are now trying to come up with a way of combusting petrol without the spark plug.

WTF?

Internal Combustion Engine (?), CNN I know... The rest is incomprehensible.

AfricanDave wrote:

Would the multiple ignition points mean the
fuel/air mix can be ignited at top dead centre, as opposed to 2 or 3
degrees before?
Also, is the increase in efficieny compared with fuel injected engines or carburettors?

Good point Dave. In my opinion, never TDC, but closer than 3 or 4 or
whatever is normal these days. Possibly 1 or less degrees. It depends
on the time constant of the pressure response.

**Audi, Kate.. Imagine you are cycling down the road. Now think of your right foot.
Do you start pushing down on the pedal before or after it reaches the top ?

I guess you would say after ?

In engines, it's the same , except the time from spark to crank power
takes a while. So to allow for the delay, we normally tell engines
to fire about 4 degrees before the power is required.

4 degrees is an angle of course, and works well at 1000RPM.

I'll explain later what happens at 3,500 RPM.

Are ye with me ?

Auditor #9 wrote:

cactus flower wrote:

Should we offer it to 905? I still feel a bit mean about having taken away his Dancing Hitler.

The one at carbibles is good too

That one is better, it is more avatar-friendly.

EvotingMachine0197 wrote:

**Audi, Kate.. Imagine you are cycling down the road. Now think of your right foot.
Do you start pushing down on the pedal before or after it reaches the top ?

I guess you would say after ?

In engines, it's the same , except the time from spark to crank power
takes a while. So to allow for the delay, we normally tell engines
to fire about 4 degrees before the power is required.

4 degrees is an angle of course, and works well at 1000RPM.

I'll explain later what happens at 3,500 RPM.

Are ye with me ?

I'll be with you if you answer this: with regard to the time delay as the crank is turning, the 4 degrees is 4 degrees as the crank is going down I presume? If we look at that avatar from carbibles then you can see the pistons are at an angle but you mean the crank all the pistons are connected to is it?

Stay on topic AT - you of all people...

Yknow

EvotingMachine0197 wrote:

Stay on topic AT - you of all people...

Yknow

Yes sir, I will. I must set a good example.

On topic, I feel that this is merely a less bad solution. The piston still pollutes and still consumes fossil fuels. We need to move to electric/hydrogen engines where such environmental devastation does not occur. We need to end the era of the internal combustion engine.

Very true Ard Taoiseach - indeed, is the internal combustion engine any good at all as a long term device? It's got too many parts which lose energy moving other parts which move yet more and so on til the wheels turn round.

The electric motor is much more efficient at doing work for the energy put in, I believe.

Anyway, back to the topic of counting the angels dancing on the head of a pin.

Auditor #9 wrote:

I'll be with you if you answer this: with regard to the time delay as the crank is turning, the 4 degrees is 4 degrees as the crank is going down I presume? If we look at that avatar from carbibles then you can see the pistons are at an angle but you mean the crank all the pistons are connected to is it?

No. Have you ever seen a crank shaft ? It's a very weird thing.

TDC refers to the position of an engine when Cylinder 1 is max up on the compression stroke.

That is when the fuel wants to hammer the peddles.

However, ideally, you would have put a match to it a few milliseconds earlier. Hence 4 degrees TDC.

EvotingMachine0197 wrote:

No. Have you ever seen a crank shaft ? It's a very weird thing.

TDC refers to the position of an engine when Cylinder 1 is max up on the compression stroke.

That is when the fuel wants to hammer the peddles.

However, ideally, you would have put a match to it a few milliseconds earlier. Hence 4 degrees TDC.

The crank shaft is parts 9 and 10 in the diagram? The piston pushes it down and while that's happening, another piston is getting pushed up - like the bicycle - one leg down the other up. So the crank is at 4º angle on the way up?

Audi, I can't explain it anymore. Get a 1995 Toyota Corolla, have a look.

Run it up. Shut it down. Lift the rocker cover, drop the pan.

Then lift the head.

Unles you are considering purchasing a German car in the future.

Then experiment on a German car. You willl need the tools.

Auditor #9 wrote:

The crank shaft is parts 9 and 10 in the diagram? The piston pushes it down and while that's happening, another piston is getting pushed up - like the bicycle - one leg down the other up. So the crank is at 4º angle on the way up?

The crank shaft would be part 6, ie all of parts 8,9 and10.
When thinking about the 4 degree angle think about the flywheel (the big wheel on the end of the crankshaft - not in the picture)
With the piston at top dead centre you could say the flywheel is at 0 degrees.
So the 4 degrees thing is taken as meaning 4 degrees on the flywheel when the piston is on its way up (in the compression stroke) and is just about to reach the top of the stroke, or when the flywheel is at 356 degrees.
I'm also having trouble trying to explain this (maybe I don't understand it properly but I think I do and even if I don't its never stopped me from being able to fix problems with my own car).
Maybe if someone can make some sense out of what I'm trying to say they can explain it in a more coherent way.

Quote :

**Audi, Kate.. Imagine you are cycling down the road. Now think of your right foot.
Do you start pushing down on the pedal before or after it reaches the top ?

I guess you would say after ?

In engines, it's the same , except the time from spark to crank power
takes a while. So to allow for the delay, we normally tell engines
to fire about 4 degrees before the power is required.

4 degrees is an angle of course, and works well at 1000RPM.

I'll explain later what happens at 3,500 RPM.

Are ye with me ?[/u]

I'm with you - but I don't know what TLA is and I'm assuming TDC is top dead centre.

EvotingMachine0197 wrote:

Audi, I can't explain it anymore. Get a 1995 Toyota Corolla, have a look.

Run it up. Shut it down. Lift the rocker cover, drop the pan.

Then lift the head.

Unles you are considering purchasing a German car in the future.

Then experiment on a German car. You willl need the tools.

Will stripping the engine allow me to see it in action ?? What's the difference between the German and Japanese cars there? German just more expensive?

AfricanDave wrote:

The crank shaft would be part 6, ie all of parts 8,9 and10.
When thinking about the 4 degree angle think about the flywheel (the big wheel on the end of the crankshaft - not in the picture)
With the piston at top dead centre you could say the flywheel is at 0 degrees.
So the 4 degrees thing is taken as meaning 4 degrees on the flywheel when the piston is on its way up (in the compression stroke) and is just about to reach the top of the stroke, or when the flywheel is at 356 degrees.
I'm also having trouble trying to explain this (maybe I don't understand it properly but I think I do and even if I don't its never stopped me from being able to fix problems with my own car).
Maybe if someone can make some sense out of what I'm trying to say they can explain it in a more coherent way.

Yes I completely understand this - you've explained it perfectly. The wheel is at 356º or -4º rather than 4º. How anyone worked this out in the first day is the maddest thing ! Crazy Daimler Benz fellas - I assume it was them who engineered it the first day. It's not that complicated an idea if imagined manually but they did it with exploding petrol ...

Kate P wrote:

I'm with you - but I don't know what TLA is and I'm assuming TDC is top dead centre.

"Three Letter Acronym"

Auditor #9 wrote:

Very true Ard Taoiseach - indeed, is the internal combustion engine any good at all as a long term device? It's got too many parts which lose energy moving other parts which move yet more and so on til the wheels turn round.

And as well as that, there is an awful lot of energy consumed in making those parts and fitting them in. All very inefficient. I think pistons and diesel and petrol are as antiquated as whale oil and steam engines, we need to move forward to hydrogen and electric. We need to crack how to store hydrogen without it leaking. The hydrogen atoms are so small they can escape containers. We need to invent means of stopping this leakage instead of messing about with the last century's technology.

A water wheel operating a belt-driven machine is a wonderfully efficient thing.

cactus flower wrote:

A water wheel operating a belt-driven machine is a wonderfully efficient thing.

Not if you're using it to drive to Wexford.

EvotingMachine0197 wrote:

cactus flower wrote:

A water wheel operating a belt-driven machine is a wonderfully efficient thing.

Not if you're using it to drive to Wexford.

Wouldn't the pissing rain keep it going?

Ecogeek update on Toyota's plans for the future of the hybrid - it'll last another few years anyway unless that air car takes off.

Quote :

Toyota has announced that they'll be selling two new Hybrids (along with the updated Prius.) One of the new hybrids will be a Lexus, and the other will be a Toyota. We don't know much more than that, aside from that they're emphasizing that they're not just another iteration of the Prius. All we've got to go on for future Toyota hybrids is the Hybrid-X concept, pictured above.

They're hoping to have Li-ion batteries in both the Prius, and the as-yet-unnamed Toyota hybrid by 2010. But they won't start mass-producing li-ion batteries at their recently-announced factory until 2011 or 2012.

Toyota seems to be looking to leapfrog some of the competition, since they're already a bit behind on Li-ion technology. President Watanabe said that they're setting up a battery research division to investigate power storage technology beyond lithium ion. It's long been Toyota's position that range-extended hybrids like the Volt simply won't work, and that we'll need to wait before we can have full-electric propulsion in mass-produced vehicles.

We'll have to see, but the future seems clear. There are going to be a lot more hybrid options in the next few years, and that will be nice for a lot of car buyers.

http://www.ecogeek.org/content/view/1753/69/

youngdan wrote:

This article is recent and discusses a few different things of interest http://www.theglobeandmail.com/servlet/story/LAC.20080526.FUELS26/TPStory/Environment This zenn company has made great strides and has recently made a deal with a maker of advanced capacitor. A capacitor is an interesting but dangerous device that is somewhat similiar to batteries. Their capacitor gives a range of 500 km at a cost of 9 dollars. http://www.greencarcongress.com/2008/03/zenn-motor-comp.html

Was it this post you were looking for youngdan?

Several car threads merged into this one - Alternative Transport.