Port size

I know this may sound stupid, but I'm just wondering.. If someone was to increase the size of their engine's intake ports+exhaust ports, how much of an increase in power would be exhibited? Would the change be very noticable/dramatic? Also, what kind of effect would this have on the car's performance in the way of acceleration? Thx :biggrin:

Edit: When I talk about incresing the port size, it's meant to include all the other mod's that are expected...

Its totaly dependant on the particular cylinder head.
You may infact lose hp, or do nothing more than alter the power curve.

And just a larger port on its own is not enough, you also need to change the rest of the system, from the cam, to the maniflod to the fuel delivery.
Even the length and size of the exhaust.

But as a general, and I mean VERY general rule the older the car the better result, newer cars will generaly have better designed ports, and so there is simply less scope for improvment.

Basicly Iv seen over a 50% increase on an old Triumph engine with a new cam ,exhaust, intake and carbs to match, but only a 10% gain on a 90s Honda with the same level of work done to it.

So depending on exactly what model of engine it is your doing it to the change can be VERY dramatic, or not even noticable.