Thanks for the kind words DD and Jmac for your lack of enthusiasm in mini engines :)

Im interested in the round port heads as the valve sizes and chamber shapes are very
similar to the best Mini A series engines. Im only looking at playing with 1300cc and
under so I feel the cheap heads are probably all I need.d

I was going to supercharge my a10 and a12 (vb10 and kb10) and was thinking I best use
the oval port heads as all the capacity in the ports I can allow will equal power.
However using the round ports cleaned up and following some of the chamber shapes that
are illustrated in that article seems like a good start.

It looks like the deep bathtub design is still kept but improvements made using less
shrouding around valves and removing the sharp edges for starters.
This depth allows the the mixture to be kept away from the cylinder walls and keep
the mix more central rather than spreading it out.

Looking at diesel engines of late they seem to focus the charge in the same manner or centred.
I think Jmac put it in the words "like a sphere" just before tdc as the best charge shape,
this sphere of suspended atomised fuel particles and air will make the best combustion.

Jmac excuse me for the not quoting your exact words as your posts are challenging :)

The problem with us carby bunch dinosaurs is that we dont have direct injection but we can
at least try to make this spherical charge effect by employing similar chamber designs
perfected by Coopers (not the Sth Oz beer company) in conjunction with concave pistons
like in the e15/16, some A14/15 and ga16 engines to help achieve the sphere charge.