Port & Polish Gains, N/A

[Robert Legere]

>So to those who have done this, how much gain did you get ?

*****Well, in terms of airflow, my own ported heads have gained an average
of 21% more intake flow and 33% more exhaust flow, with a better
intake-to-exhaust proportion. This is with standard valves, and not overly
enlarged ports. Combustion chambers have been unshrouded as well. I suppose
any competent head porter can match this or improve on these results. In
terms of outright power increase, that cannot be determined solely from
airflow increases, as it depends on the state of tune of the rest of the
engine.
    In terms of costs, you should be aware that it should not take over 6
hours to port an SR20 head to the point of improvement I've mentioned, in
fact the last one I did only took 4 hours, and I'm not a hack. So not
counting additional machine work (valve job, guides, assembly), you may want
to ask how much of your hard-earned cash is being  directed at the porting
part of this procedure.

Bob