Square port/oval port

[mat_fenwick]

I am replacing the 1.9 NAD engine in a friends ZX with my 1769cc TD (minus turbo), as he needs to be mobile quickly and cheaply. I figure this will be fairly easy as I won't need to uprate the radiator or mess about getting the exhaust to fit onto the turbo.

BUT, I hear that there are difference in the ports on the heads between BX and ZX engines. My understanding is (which may be wrong!) that BX engines have square ports, and ZX engines oval ports. Question is: can I just swap the ZX manifold onto the BX head? He's not too bothered if it loses a bit of power (let's face it, a non turbo 1.7 isn't the quickest anyway) but if it is really going to screw up the exhaust gases leaving the head then I may have to search for a replacement manifold.

[docchevron]

Early XUD's were square port, later one's oval port, so assuming your engine isn't an early engine the ports should be oval.
As for the viability of just removing the turbo and expecting the engine to run anywhere near satisfactorily is very questionable.
If you're going to swop the cams and the inj pump, then fair enough, but if not........

[mat_fenwick]

Thanks for the reply, the ZX is a 96/97 model and my BX is a 93 - I will probably know later today which type the BX is...

Yes, I was going to swap the cam and blank off the boost pipe on the injector pump, tell me if I am missing something