Recommended press fitting for valve seat inserts in aluminum cylinder heads:
OD insert 30 – 40 mm: 0.15 mm / 0.0059″
OD insert 40 – 50 mm: 0.18 mm / 0.0071″
Spindle speed for cutting a seat pocket in aluminum cylinder heads: 400 – 600 rpm
It’s recommended NOT to freeze (f.i. with liquid nitrogen) the sintered valve seat inserts before installation.
The valve seats are to be pressed in with a flat and square seat driver tool. The valve seat is inserted with the radius side down.
Source: DuraBond