Correct valve seats dimension

[eugene]

Hello
I ordered a set of 44 mm intake and 38 mm exhaust valves (type 4), but the seats i got for them seams too big to me. The intake seats is obviously for an 48mm valve and i will get those changed for smaller. But now after a better look also the exhaust look little too big. They measured 41.4mm on the OD and 34.6 on the ID. Is this ok for a 38mm exhaust valve or are those made to fit 40mm ones? Also how much should be the correct measure for 44mm intakes? Thanks.

[Udo]

I think 2 mm more than the valve diameter is ok

Udo

[eugene]

The seat looks just a little too big. If i shot for a 1.8 mm wide valve seating area then there is app. 0.45mm of meat left to cut the third 70° angle. Or port ID/valve dia. ->34.6mm/38mm = 0.91.
Is this to much for a street engine?

I looked in the scat catalog and the seat for the 38 mm valve is 41.4 OD and 35mm ID, so the valve seat i have is right according to scat. The seat for the 37mm valve is 33.4 mm ID btw.