The block and the bottom end would never stand up to the stress and pressure of compression ignited fuel. If the engine were to be torn down and rebuilt frequently it might work for a while. Peak pressures are far higher with compression ignition (all fuel burned at once) then with the controlled flame front of gasoline spark ignition. The block would need to stiffer (maybe compacted graphite iron) and the bottom end bearing surface would need to be increased. Multi pulse direct injection could alleviate some of the peak stress but a better starting point might be the new Ford-Jag-Range Rover Lion series engine.