Raptor 2 is SpaceX's full-flow staged-combustion engine: liquid oxygen and methane at a mixture ratio of 3.6, 300 bar in the main chamber, 230 tf at sea level, 1,630 kg dry. Every drop of oxygen passes through an oxygen-rich preburner that spins the oxygen pump, and every drop of methane through a fuel-rich preburner that spins the methane pump; the two hot gases meet in the main chamber, which has no igniter of its own. The load cell above the gimbal reads the thrust while it burns.