Novel, highly-stratified combustion strategies are required to efficiently use renewable hydrogen, methane, ammonia or methanol in large engines for power generation. This can be achieved by Spark-Ignited Mixing-Controlled Combustion (SI-MCC), in which a fuel jet or spray is directly ignited by a spark, to establish Diesel-like combustion. Existing research provides a proof-of-concept for SI-MCC with hydrogen, but the ignitability of other fuels remains uncertain, especially for liquids. Several phenomena are already known to affect the ignitability of highly-stratified systems at ambient conditions. However, it is not yet known how these affect the ignitability of fuel jets and sprays under engine conditions. This proposal studies SI-MCC ignitability with hydrogen, methane and methanol and aims to understand the key phenomena influencing ignition. Experiments in an optically accessible combustion chamber will investigate the ignition success for different ignition timings and locations of the spark over the jet/spray, and provide fundamental data. The local conditions at the spark are assessed via simulations, while high-speed videos provide detailed insight into the ignition process. Given modelling is at an early stage, the conclusions will be presented as a conceptual model that shows how different fuels ignite, by indicating the phenomena of interest and describing the influence of fuel properties.