As we have several different combustion chamber shapes in our engines, why don't we just put up a comparison picture thread here? I have couple of pics to start with...
ECL-C


ECZ-C



ECZ-G




C0AE



Can't remember which this is (have to check it out next time I crawl to garage)



I think I had ECRs once too, but those were scrap, so I throw them away before shooting any pics...

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)