We experimentally investigate four-wave mixing and nonlinear losses in low-loss 3 μm thick silicon strip waveguides. Adiabatic bends allow for single-mode operation in an ultra-compact 35 cm long spiral. The waveguides exhibited reduced nonlinear losses due to the large mode area of 2.75 μm22.75 μm2. The nonlinear coefficient 훾γ was measured as 5.5 m−1 W−15.5 m−1 W−1. These features, along with the low propagation loss of 0.17 dB/cm, enable large idler power generation at 1550 nm.