Answer : The repeated opening and closing of valves causes an impact on the valve seat. The valve and seat should provide a gas tight joint for compression of the charge in the combustion chamber.
The valve seat grinding machine PEG 8 is the model for those who have to rectify valve seats of small engines such as motorcycles or cars. Its working range in fact covers a diameter range of Ø 16 ÷ 48 mm. It is only available in the Standard, Univer, Motorized Unit Only and Avio versions. Working field. Ø 16÷48 mm.
There is no better machine for grinding titanium valves. There are no new TA machines. IDL Ingenious Devices in Canada decided to take a stab at the valve grinding market sometime in the mid eighties. There is a source for wheels for the IDL compared to KW and Sioux.
The object of grinding or cutting is to obtain a valve seat of a specified, uniform width in the correct position on the valve face with minimal stock removal. Throat Angle: generally 60°, this is the bottom angle which transitions airflow from the seat angle to the port. A couple of cautions right up front.