Bigger Valves for M20B25 Head

[reggid]

Is it possible to use bigger valves for the intake and exhaust? What is the maximum size that is recommended? Are there any issues with doing this?

Thanks

[Turbo-Brown]

There appears to be almost no point in installing bigger exhaust valves it seems.

Any idea how big the valve seat inserts are for the inlets, there's no point fitting bigger valves if the throats can't be opened up either.

[reggid]

There appears to be almost no point in installing bigger exhaust valves it seems.

Any idea how big the valve seat inserts are for the inlets, there's no point fitting bigger valves if the throats can't be opened up either.

Alpina fitted bigger valves to their C2 2.7, but it may have been with a different head...no?

[Turbo-Brown]

No idea to be honest, but if they used the 2.5 head as a basis, they must have made the holes in the head bigger or fitting bigger valves wouldn't have achieved anything.