Zetec:
ZX2 HP: 130 @ 5750
ZX3 130 @ 5300
ZX2 Torque: 127 @ 4250
ZX3 135 @ 4500
Bore x Stroke: 3.34 x 3.46
Compression: 9.6
Displacement: 1983
2.0 SPI(Base model Focus and Escort/Tracer engine):
HP : 110 @ 5000
Torque : 125 @ 3750
Compression: 9.4
All the rest is the same as the zetec
Protege 2.0:
HP: 130 @ 6000
Torque: 135 @ 4000
Displacement: 1991
Bore x Stroke: 3.26 x 3.62
Compression: 9.1
Of course I could be wrong, but I think they are different engines.
The zetec engine comes from Fords long line of CVH engines. I know it atleast started in 1981 with the 1.6l cvh in the escort, but it may have started in 1968 with the 1.6l Kent Crossflow engine, but not sure since a lot of people get the two confused as being the same anyway. The zetec is basically a dohc version of the cvh engine.
Outside of the Probe/MX-3 Ford has only used two Mazda engines in their cars to the best of my knowledge, the 1.6l and 1.8l bp. The 1.6l was in the capri and tracer(which was a 323 clone before 91). The 1.8l was in the escort gt/escort lxe/tracer lts/laser line. Their might be some shared parts between them(like the oil pump being the same in the zetec, escort and mazda 1.8's and the civic, but thats nothing new to cars these days. There, more then you every wanted to know
Most likely in the future 4cyl engines will be shared between Ford and Mazda as the next generation has been codeveloped between the two.
As for going turbo, Gude also has a kit and possible another company(not sure who). Try asking about it at club-focus.net and zx2.com. It would be my advice to stay away from gude though, someone was just talking about them on the egt list. Aparently they like to sell parts for cars that don't exist(ie 1.6l dohc escort from 91-96) and get very arrogant when people try to tell them it dosen't exist.
Oh, and as for the turbo FRT200, companies can get an engine to do anything they feel like. That dosen't have anything to do with what came out of the factory, you can bet the regular ZX3 isn't going to have a turbo ready engine. It would take a hell of a lot of work to get the power of the FRT200, if thats what your thinking. Everything - Fuel system, fuel injectors, complete engine rebuild most likely, computer, etc. Probably not something you would want to pay a shop to do, with the labor and all. Also, you would want to get a warranty on it, which makes it even more complicated. They screw up and your engine blows up are they going to pay for it, or just say it was you driving it hard? And what about the warranty on your car, big gray area on what Ford will cover if something goes wrong. Adding a turbo can void your warranty, you would want to make sure Ford will still cover it, they might not even if you use their parts.
You can slap on a turbo with a little work as long as you keep the boost low, but then whats the point in the turbo?
Something else to consider is bolting on the parts that make it an svt focus. It might be cheaper espicially if your not interested in the suspension and transmission. From the press release I saw it sounded like Ford was interested in selling the parts, I don't know if they are or not.