Hemis provide good (optimal?) thermal efficiency. That is the combustion chamber is more or less a sphere with greatest internal area and smallest external surface and therefore retaining the most thermal energy.

Some research has focused on creating a vortex within the cylinder to draw fuel to the center of the combustion chamber. This increases thermal effieciency because combustion is miniumsed at the chamber surface.

Fly sprays and spray painters use a static charge to focus paint/spray onto the target. In the same way an electro-magnetic charge and direct injection can be used to focus the charge inside a combustion chamber.
-- madness, Jul 05 2004

Hmmm..... gonna have to think about this one. Don't know if it could work or not. It could be tricky to manage the charge and not set off the fuel.

As I work on engine accessories for the Hemi I'll run the concept past some engine research geeks at work and see what they come back with.
-- RayfordSteele, Jul 06 2004


As I understand the painting process, the charge on the piece being painted attracts the oppositely charged paint/powder uniformly to the charged surface.

This proposal sounds as though it would essentially be the opposite of that; repelling the air-fuel mix from all surrounding surfaces (and, of course, not repelling it away from the spark plug). Is that something that can be accomplished with a magnetic field? How reactive is an air-fuel mixture to electromagnetic fields?

Or am I visualizing it incorrectly? Are you proposing that the air-fuel mixture be attracted to the spark plug electromagnetically?
-- half, Jul 06 2004


Well, gasoline tends to acumulate static charge anyway--that's why you put the can on the ground when you fill it, to keep it grounded so it doesn't spark and blow up. I'm pretty sure gas accumulates the negative side of the charge, so if you somehow positively charged the spark plug then the gas should be attracted to it--but this might make it start condensing out of the vapor as well. Hard to say if it would do what you wanted it to.
-- 5th Earth, Jul 06 2004


I thought that static charge & gasoline thing was due largely to the use of plastic containers. The gasoline itself accumulates a charge? From flowing through the hose?

I think the proposal is to use magnetic fields to corral the air-fuel.
-- half, Jul 07 2004


Hmmm, I was a bit incoherent when I wrote electro-"magnetic" charge. I was thinking about the electro-"static" charge used in the painting process. I was also thinking about the stratified charge created using direct injection. There are (currently) two types of direction injector for gasoline engines. Those that inject fuel and those that inject a mixture of fuel and air.

Mitsubishi (and others) produce fuel only injectors and Orbital (from Austraila) produce fuel/air injectors. The Orbital system is used widely on outboard motors (Optimax).

The Mitsubishi system creates a stratified charge (bunched around the spark plug) for economy using less fuel and directed flows within the cylinder on induction. The stratified charge is more (thermally) efficient and generates more power with the small amount of fuel. For out right power the mitsubishi injectors use more fuel and unfortunately loose the statified charge.

Perhaps this system can be used to produce a stratified charge even increased fuel levels.

As I understand it there are no sparks generated during the paining process. Hopefully (I have not done any calculations) there will be a sweet spot where fuel can be charged without creating a spark.
-- madness, Jul 08 2004


On reflection I am not sure that a static discharge is going to be a problem. Given that the fuel is atomised on injection (so that is does not need to mix in the cylinder on compression), injection can be left until ignition is required.

The Orbital injector with its high pressure air/fuel mixture atomises fuel better than fuel only injectors. Perhaps the problem can be turned into an advantage and the spark plugs can be eliminated...

[buddha_pest] //Is good combustion* promulgated by having a dense fuel mixture (probably without the requisite air mixed in) next to the spark?//

As I under stand it keeping the fuel away from the cylinder walls ensures that almost all the heat/engery in the fuel is expended on the gases moving the piston.
-- madness, Jul 08 2004


[drivel] ...And then you have a diesel engine. Albeit with higher octane fuel.

[buddha_pest], I don't think that charging the plug and then sparking it would be too hard. Different mechanisms would be used. Now that I think of it I know how it could be done--just put a small Van de Graaf generator in the car, and hook one end to the plugs and the other end to the injectors. Since the actual spark in the plug is grounding in a different circuit everything should be fine, but if you're worried abaout damaging the generator, since they ARE electrically connected, just physically disconnect them when the plug fires. Simple.
-- 5th Earth, Jul 08 2004


on the static charge problem it is the car that is charged the nozzle discharges this, the mini had problems when they used the wrong paint round the filler cap.
-- engineer1, Jul 09 2004



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