Originally Posted by Lscman
I'm with you on this head swap mod for N/A apps. Ford did not install a smaller port head on the 2.0L to make it inferior. It was done to better match the head flow to the cam, to optimize powerband, output and efficiency. The bigger head belongs on the 2.3 or on a 2.0 with cam swap to raise the powerband. It's wrong to assume that a head swap will lead to 2.3L powerband or similar peak horsepower. The 2.3L is about 15% larger displacement and this is what makes it about 15% more powerful. It's not the head flow doing it.
Yes I agree w/ you. ^^^^^ I'd just throw a 23 on board. Mazda's MX-5 is a 20 w/ 170 hp. I'd bet they are using a 23 head. The head on the 20 foci has smaller ports for velosity= air flow, for the shorter stroke. Its not like a lot of regular joes are driving MX-5's.