[pgfpro]

Originally Posted by Logic

I came up with that means of optimizing valve/chamber shape (Tuliping. Thx freebeard) ages ago while gas flowing my Alpha Giulietta 2L head.
I miss that car! If I knew then what I know now..!

I'm getting my head around what you have said (and not! ) in the rest of your reply.
We'll chat more on that privately. But we are heading into territory where a picture (and gesturing) is worth a thousand words... (in a trustworthy ear!)

IIRC your compression ratio and AF ratio numbers aren't much different!? Hats off on that!

If I understand things correctly (with almost no research) the pre-chamber is basically about creating a very big 'spark' that lights more AF up faster, at a better crank angle closer to TDC, by setting fire to that separate mixture at a/the 'timing advance' that would otherwise be unworkable?
ie:
IF there was a way to create a VERY large spark (or 4...) one could do away with it..??

Hydrogen:
I NB that the previously discussed copper plating that creates a bit of H, more during/after the main combustion event, does not suffer from that drawback in a pre-chamber!

There are a good number of other possibilities for getting some 'free' H2 or Ozone type radicals out of an engine.
eg: A constant but separate (dioded) Ozone producing voltage (circuit) on the spark plug.
I'll get back to you on that when more of my vast multitude of ducks are in a row!
(I'm researching senescent cell clearance for my Mom (urgent) too atm, which is taking a lot of my free time)

Lots of good stuff here, thanks for the reply. In short what the pre-chamber does is makes its chamber an A/F rich area. I suspect the pre-chamber A/F during light load FE mode is around 16:1 to 20:1. The normal combustion chamber A/F is at 30:1 plus. Without the pre-chamber even with my race extremely high energy ignition system the engine starts to misfire above 20:1 A/F.

The second major thing the pre-chamber does is it creates a very powerful flame torch. This is due to its shape. The torch that enters the normal combustion chamber covers a lot of distance and a much larger area then a normal CC. This helps light off the very lean A/F area in the CC with a complete burn of all the fuel. The flame torch also increases flame propagation. This helps the extremely lean normal CC that without the pre chamber at a A/F ratio of 30:1 would have a very low flame speed. This where all my testing using my home-built gasoline combustion chamber paid off.