Internal combustion engine emissions using pure oxygen.

Combustion engines run fuel-rich to keep the flame temperatures down. Stoichiometric combustion might have a flame temperature of 2500 to

I think you didn't read his idea thoroughly. With no nitrogen in the combustion chamber there would be no NOx

Which is not far off how a Diesel engine runs especially at low throttle, Huge excess of air, and very high combustion temps and explosive knocking - the diesel 'idle rattle'

Manufactures tamed that with multiple small injection pulses ...

Very high temperatures are conducive to high efficiency but as you correctly point out come with their own issues. Ceramic piston in ceramic cylinder? Or perhaps water injection.

I think the ideas might work better in a gas turbine, but in fact what he is describing is in fact rocket science.

Its possibly a net idea - like the one I heard at an engineering conference of using rust and coal dust in a steam boiler furnace. Burns very hot and produces almost pure CO2 and liquid iron.

The CO2 you put in a tank, and you blow air through the liquid iron to produce new rust....

It worked but wasn't enough of an improvement to warrant the cost.

I recall some years ago seeing reports that households would soon be using combined heat and power units based on ceramic engines the size of a shoebox (who knows what a shoebox is today?). Obviously, this was before the whole CO2 = bad thing started, so quite a while back.

The older you get, the more amazing new technologies you see on TV that never actually happen...

Yes, and the more things happened that no one actually expected. Technology advance is always a question of what is cheap aqnd doies something genuinely useful or fun. But te 'preductions;' are alwsy massive technology that will solve the problem we want solving, irrespectibe of whether any practical technology exists. Viz the fight between nuclear power and renewable energy, the one a product of careful sound engineering and the other a fantasy cobbled together by cynics to sell to ideologues

What if the amount of fuel and O2 injected into the cylinder was only enough that when combustion was complete the new volume of gas was equal to the volume of the cylinder at BDC so effectively the cylinder was at atmospheric pressure?

Clearly I am not thinking about car engines here.

So would this indicate that all the useful energy to be extracted had been? Then the upward stroke would simply be exhaust, no compression needed.

If anyone knows what sort of exhaust would be produced from burning the fuel in only O2, I would be interested to learn, thanks.

There wouldn't be much, if any NOx, but the exhaust valve would melt