Every man and his dog has been playing with HCCI, Bobbin! The range of operation is quite small. It won't work at very low load, very high load, or high engine speeds.

I knew I could rely on you lot! :-D Cheers

The other big issue here is that you have just removed one of the most effective ways of controlling a petrol engine to get either peak output or best economy at given revs, the ability to advance and retard the ignition.

Also it breaks Rule One: If it ain't broke, don't fix it......

According to some, if a petrol engine is run on supermarket fuel, it'll immediately turn into a compression ignition engine.

Nope-it's not controlled!

I think it's the exhaust valve which acts as a glow plug. The spark plug (they're not your KGN platinum tip!) does burn out but it doesn't melt. The engine survives because it runs nitromethane to air on a roughly 1:1 ratio-almost 80% rich! And a run is only 5 seconds.

In alliance with the oil producers, they care only for their own wealth.

As opposed to the rest of us that work only for the good of disabled orphans? This is the sort of nonsense you see on cif at the Graun.

There is sound reasoning behind a compression ignition petrol, but the reality is that the implementation is extremely difficult.

Yes, but HCCI is the only one really worth bothering with since it successfully addresses the efficiency problem of a conventional petrol and the emission problem of a conventional diesel. It also uses entirely conventional architecture. That said, I'm not entirely hopeful.

Most prototype engines seem to address a problem that exists only in the designer's head. The revetec crankless engine for instance. The creater of this masterpiece is convinced that the crank assembly is responsible for a great deal of inefficiency in a piston engine and set out to solve it with contra-rotating cams. They've actually built and tested of these designs which puts it in a very rare breed. Beautiful machine-but based on a premise that is quite wrong!

Then there are the ones who can't even get their thermodynamics 101 straight and pursue hopeless tasks like trying to 'capture' exhaust heat and turn it into useful work. the 'six stroke' engine falls into this catagory. No one has thought of that before...

3 way cats don't help, but it's not an EGT problem. 3 way cats can't reduce NOx if there is oxygen in the exhaust. That is what killed conventional lean burn. If you run slightly lean (say up to an AFR of 25:1) cylinder temperatures are high enough to generate NOx. If you go leaner, spark ignition doesn't really work.

HCCI can operate at ultra lean mixtures which keeps cylinders below about 2000K so NOx production is low-hence no need for 3 way cat.