ESE's works engine tuner

[Frits Overmars]

Frits all ICE have flame fronts, even gas turbines do. The speed of the front is down to the intensely and size the of the turbulence regime.As the species get smaller the front wrinkles are greater and the front area itself increases.
The greater the front area the faster the fuel/air volume is burnt. As rpm rises the turb rises too staying ahead of any wall hitting.
A large % of why very high revving engines need less anti-knock octane

Everything you say about flame fronts is correct, Dutch, with one exception: not all internal combustion engines have 'm.
A flame front, like the name says, is the frontier between burning mixture and not-yet-burning mixture. In HCCI combustion there is no such frontier. A random spot of mixture is not ignited by a flame; pressure rise and radiated heat cause it to ignite spontaneously. The time for the whole charge to be consumed by burning can be tens of times shorter than with flame front combustion.
Sounds familiar? Yep, the same description fits detonation....

[husaberg]

Everything you say about flame fronts is correct, Dutch, with one exception: not all internal combustion engines have 'm.
A flame front, like the name says, is the frontier between burning mixture and not-yet-burning mixture. In HCCI combustion there is no such frontier. A random spot of mixture is not ignited by a flame; pressure rise and radiated heat cause it to ignite spontaneously. The time for the whole charge to be consumed by burning can be tens of times shorter than with flame front combustion.
Sounds familiar? Yep, the same description fits detonation....

Frits the EXP2 was a controlled version of that as well did it not.
It had some typical Japanese Letter based jargon RARC or something?

[Frits Overmars]

Frits the EXP2 was a controlled version of that as well did it not. It had some typical Japanese Letter based jargon RARC or something?

Yes, it was Honda's ARC (Activated Radical Combustion). The Honda EXP2 had an exhaust power valve that could severely restrict blowdown, so a lot of hot residual exhaust gas remained in the cylinder where it mixed with the next charge of fresh mixture, heating this mixture so it would self-ignite at the end of the compression phase. In Honda's case this only came into play at part-throttle. The Ryger is cleverer: it does not need an exhaust power valve at all and it works at WOT too.

[husaberg]

Yes, it was Honda's ARC (Activated Radical Combustion). The Honda EXP2 had an exhaust power valve that could severely restrict blowdown, so a lot of hot residual exhaust gas remained in the cylinder where it mixed with the next charge of fresh mixture, heating this mixture so it would self-ignite at the end of the compression phase. In Honda's case this only came into play at part-throttle. The Ryger is cleverer: it does not need an exhaust power valve at all and it works at WOT too.

Well remember that Suzuki you posted it could do that too by proxy could it not?

In 1962 Suzuki even gave the B-port (there were only two A-transfer ports and one B-port) the same timing as the exhaust port.

Attachment 312434

[Frits Overmars]

Well remember that Suzuki you posted it could do that too by proxy could it not?

Attachment 312434

a lot of hot residual exhaust gas remained in the cylinder where it mixed with the next charge of fresh mixture, heating this mixture so it would self-ignite at the end of the compression phase.

There is a damn thin line between HCCI and detonation, which is why Suzuki stepped away from their high B-port after one year of trying.
Mind you, they weren't even looking for HCCI; they just wanted to put some exhaust gas pressure on the crankcase contents.

[husaberg]

There is a damn thin line between HCCI and detonation, which is why Suzuki stepped away from their high B-port after one year of trying.
Mind you, they weren't even looking for HCCI; they just wanted to put some exhaust gas pressure on the crankcase contents.

Pleasure and pain.

[SwePatrick]

That doesn´t seem to be a problem in f1 cars (old WTCC cars comes to mind as well). Maybe because they run lower compression or fuel diferences?

It´s all relative to pistonspeed.
An F1 engine doesn´t have that much of a pistonspeed to brag about.
Take an 500cui top fuel engine at 10000rpm as an example, there´s speed for you

[SwePatrick]

Maybe flame front speed comes into play past 20,000 rpm where the power is dropping due to
time/area constraints as well.
But as the Ryger makes it 70Hp at 17K, this is obviously not affecting efficiency at all.

If peak power is at 17krpm then it´s possible.
Revving 30krpm is just a number put out for some reason.
Maybe it´s what the geometry in engine can take without spitting parts on track.
But i don´t belive they´re makin any power at those revs.

[adegnes]

Wobbly, the microblue treated bearings you mentioned some time ago, are they from this manufacturer, or other brand treated with the coating?

http://www.microblueracing.com/index.html

Re Ryger, sooo... HCCI it is then?

[MotleyCrue]

http://www.sumobrain.com/patents/wip...13185802A1.pdf

[breezy]

http://www.diva-portal.org/smash/get...FULLTEXT01.pdf

interesting hcci pdf

[adegnes]

http://www.diva-portal.org/smash/get...FULLTEXT01.pdf

interesting hcci pdf

Nice!
Btw, I have no problem reading swedish, or danish(both languages very similar to norwegian), and am happy to translate. No actual need in this case, but now you know.

Edited - grammar...

[wobbly]

Yes I use the USA Microblue polished and treated races with ceramic balls in all manner of race engines.
Way less friction and they last forever.

[Haufen]

Re Ryger, sooo... HCCI it is then?

I don't think so. HCCI has always been a low load combustion process only.

[2005bully]

After following this forum for quite some time this is my first post. I do not want to detract from the current exchange of ideas.. but found this link that offers some good insight to the HCCI process. http://cdn.intechopen.com/pdfs-wm/43660.pdf