MeV/amu ion enhancements associated with corotating high-speed solar wind streams in 1978-1986 during pre-solar maximum to near solar minimum conditions are studied using ISEE 3/ICE, IMP 8, and Helios 1 data. Around 50% of corotating streams contain energetic ion increases. These increases extend to [approx]25 MeV/amu, where they merge into the galactic cosmic ray background, and are most evident approaching solar minimum. Sunward ion streaming in the solar wind frame (first-order anisotropy [approx]20%) and positive radial intensity gradients ([approx]400%/AU) are consistent with acceleration in the outer heliosphere at corotating shocks followed by streaming into the inner heliosphere. The spectra and intensities show little solar cycle variation. The spectra of ions from protons to Fe at [approx]2-20 MeV/amu are approximated by exponentials in momentum. Ion abundances are correlated with the stream peak solar wind speed. Mean abundance ratios in slower corotating streams (maximum solar wind speed