LocostUSA.com

http://www.turnology.com/news/f1-tech-w ... t-ignition

excerpt:

"TJI replaces the spark plug with a jet ignition chamber. During the compression stroke, around 97 percent of the fuel charge is injected directly into the cylinder and the remaining three percent of fuel is directed into the chamber where a traditional spark plug ignites that small, overly rich charge within the tiny confines of the chamber. The resulting high-pressure jet stream of hot gasses are forced through a number of tiny holes in the chamber and into the main cylinder to ignite the rest of the air-fuel charge, which is by now thoroughly mixed and lean. According to Mahle, these hot jets fire out to the edge of the piston to ignite the mixture."

_________________
***************
Geek49203 aka
Tim Wohlford
Louisville, KY
Hayes front, S10 +2 rear, Lalo body.

I looked at that and immediately thought ROTARY!!!

This would allow a more complete burn which would reduce emissions, reduce gas consumption and should fatten the power curve.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

That's a prechamber. The very best 1920s technology.

"What goes around comes around."

Back in the late '60s-early '70s Ford put a lot of effort into it but couldn't keep the emissions below California requirements. Of course that was analog controls and no catalyst.

double tap, somehow...

Honda did that as well back in the 80s I think.

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Well it is and it isn't the old pre-chamber. The best you can say is that it's based upon the old pre-chamber.

It's using a chamber in the spark plug rather than the head, but the injection is different and the burn pattern(s) is WAY different.

With the advent of the precision control that computers give us there's a whole lot of stuff that was tried once upon a time and didn't work, can now work.

Turbos & Superchargers are just the tip of the iceburg.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

Well, a precombustion chamber is a precombustion chamber. This one is outfitted with all the current bells and whistles, which is good. Makes me wonder what this does to the importance of direct injection.

Bill

I wouldn't think it would make any difference towards direct injection. This seems to me to be more about flame travel.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

All the big stationary engines that run natural gas compressors at work use prechambers too. Mostly inline 12 Cats and V16 Waukesha's. They run spark ignition on natural gas with a turbo. I'm not a mechanic, so I don't really get to see them tore down, but I try to weasel my way in so I can have a look when there's mechanics doing a rebuild. I'm still not sure on the theory behind the prechambers though.
Kristian

_________________
V6 in a book frame build. Now registered.
viewtopic.php?f=35&t=7587
viewtopic.php?f=33&t=18172

I haven't dug deeply into the issue, but I thought the driving force behind direct injection was to achieve efficient burning of very lean mixtures. Wouldn't this technology address that issue?

Bill

That makes me think erosion. Those hot gas jets would burn through tiny holes in a prechamber. Very limited cylinder head life. Likely wasted after a single long race.

I have a cast iron engine block that has flame cutting between two cylinders after the engine was used with a blown head gasket.

Ceramics?

Bill

High nickle alloys usually are used for prechambers, at least in diesels.

_________________
Walt
06 RX-8 Shinka
04 RX-8 GT
06 325xi
Some people never have anything except ideas. Go do it.
Emissions & fuel economy haven't exactly been areas of strength for past rotary power plants, but absolutely no one with a soul has ever cared.

Simply make it replaceable. It screws out with the spark plug and all is replaced every time.

_________________
mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

The basic idea is to allow a rich mixture in the prechamber, which is lit and then proceeds to ignite a leaner (often too lean for normal spark ignition) mixture in the main chamber. It's usually more fuel-efficient than a normal combustion chamber.

It works just fine for gasoline engines, but it drives various regulated pollutants up very high; mostly oxides of nitrogen (NOx). Last time the prechambers came around predated three-way catalysts, which are helpful for NOx emissions.

A lot of things came and went, not because they weren't useful, but because they weren't practical at the time. Back when aircraft used short exhaust stacks, pilots would trim the fuel and spark until the flames went away and the smoke changed from black to white. That meant the engine was running right on the edge of the detonation zone; the entire fuel/air mix burned without a distinct flame front across the chamber. This increased the effieciency a lot. It was only practical on aircraft engines without exhaust manifolds, running at constant speed. It faded away when aircraft began using exhaust manifolds instead of stacks, mostly in the early 1940s.

The idea came back a few years ago as "Homogenous Charge Controlled Ignition", or HCCI. The engine management system is able to diddle the fuel and spark to the edge of detonation and keep everything under control with sensors and feedback loops.