This Small Business Innovation Research Phase I project involves development of a new family of thermally-stable, high-strength aluminum casting alloys for engine cylinder head applications. There is a strong push globally to improve internal combustion (IC) engine efficiency, through down-sizing, turbo or supercharged boost, and through the use of alternative fuels. All of these approaches increase the operational temperature of the engine beyond what current aluminum engine alloys can sustain, leading to dimensional changes which can cause engine failure. At these higher temperatures, the new alloys to be developed will retain engine performance and life, while maintaining the low weight, castability, and cost-effectiveness of standard aluminum alloys. Our initial focus is on two-wheeled motorcycles and other recreational vehicles that represent a total market capitalization of $35 million, just for cylinder heads. There are many follow-on markets including diesel generators, and engines for outboard marine, small aircraft and even automobile vehicles, where the total markets are estimated in the billions of dollars. The intellectual merit of this project is the replacement of traditional gravity- and die-cast aluminum alloys with higher performing materials at a competitive cost. These aluminum alloys will contain heat-resistant nano-precipitates, which will not dissolve at high operating temperature and pressure, thus retaining the component strength, toughness and microhardness. With production of millions of IC engines each year, a new high-temperature alloy will lead to significant energy reductions. Current automotive and motorcycle aluminum engine components, such as cylinder heads, blocks and pistons, are limited to an operating temperature of roughly 220 deg. C. Modern and future engines require higher operating temperatures of up to 290 deg. C and pressures up to 21 MPa to meet demands for higher engine efficiency, reduced vehicle mass and fuel consumption, increases in the power-to-mass ratio, and lower emissions. The 2025 Corporate Average Fuel Economy (CAFE) regulations require an efficiency of 54.5 miles per gallon for light duty vehicles by 2025. The need for improved IC engine efficiency is urgent, thus increasing the demand for novel high temperature aluminum casting alloys.