July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Valve seats

Fig 1: Valve Seats -- Specifications, Mechanical

Courtesy of VOLVO CARS OF NORTH AMERICA.

Angles

A	Upper inlet reduction angle........20° Upper exhaust reduction angle........15°
B	Inlet and exhaust matching surface angles........45°
C	Lower reduction angle........60°
a	Width of the intake valve seat........1.4-1.8 mm Width of the exhaust valve seat........1.8-2.2 mm