McDat in this case you are getting personal business jargon, the wider the port the worse the flow as the air charge needs to be kept tightly into the centre of the bores with minimum fuel coating the bore walls as it goes in and tumbles. The less the charge has to deviate before it goes through the valves the better, look at any Honda ports for reference its all about good tumble.

The CADET 4 port heads are like SR20DE, EVO 4g63 and Honda Ports, the opened up 8 port to 4 port conversion has horrible dividers as they create more turbulence than properly tapered more smoothly tapered and further inset dividers. Look up Ninja or Hayabusa turbo threads on how turbo people shape this divider on already fantastic factory ports.

Look at any performance modern 4 valve head engine they avoid going wide instead go narrow and tall. The bigger the ports is not the solution, the 8 to 4 port conversion makes them way too big. The 4 port is just right but almost overboard itself. Mine is comparable to 4g63 in size and slightly bigger than most Honda performance heads. 1 persons flow bench and business means squat compared to Japanese engineering. In Germany folks term them Autobarn versio of the CADET. Also the 4 port roof can be raised higher again they have more meat all round.

Wide ports will never flow better than taller ports even latest bike engines go round and Honda has stuck with 45 degree valve angles for a long time with the same port shape as the cadet 4 port.

EDIT: SOLD

This nicer tidier soother inlet for halve the price would work very well.
http://www.ebay.com/itm/INTAKE-MANIFO ... sh=item27cf8cc409&vxp=mtr

SR20de (top) vs later SR20Ve (bottom)
you see the shape of the ports on perhaps the most successful late nissan engine? for the VE they went even narrower.

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