Beryllium Seats The almost universal use of Titanium valves in high performance engines has forced engine builders to use Beryllium copper seats for years. Titanium, which is 40% lighter than steel, does not conduct heat very well. The use of a Beryllium Copper alloy is a superior material for heat dissipation as compared to steel seats. Mathew Performance Products offers the following Beryllium Copper alloy seats: INTAKES: Special Alloy available in 2.060 and 2.070 OD with a 1.700 ID. EXHAUST Special Alloy available in 1.754 and 1.764 OD with a 1.400 ID. Both Intake and Exhaust sizes available in 0.400 and 0.450 thickness.