Do all counterflow heads have the same port shapes, separations and inclinations? I know some have an injector port and others don't but I am only interested in the port geometry.
The exhaust port is flatter and has more of a 90deg turn into the combustion chamber, the inlet is angled slightly so the port opening sits higher up in the head. The inlet is slightly larger than the exhaust. All inlets are the same size but two in the middle sit very close together. Looking at the head from the rear the ports go E-I-E-I-I-E-I-E where E = Exhaust and I = Inlet.
Thanks Jettin', but what I am asking is are all counterflow _heads_ the same with regards to port geometry. I need to know because I need to make up some throttle body runners so I need a head as a template but I want to keep driving while the runners are being fabricated, so if I buy any counterflow head will it be the same port geometry as the head on my engine?
All of the big bore engines (1.6 / 1.8's) in mk2's can have the inlet and exhaust manifolds exchanged. This says that the port sizes and geometry are the same. Have a look at the manifolds that came of the car. I take it you know that counterflow means that the inlet and exhaust are on the same side. Crossflow is the american / mk4 head where inlet and exhaust are on opposite sides. If you are talking about the crossflow I would speak to the yanks over on Vortex as they have had that head for years.
