I saw Find's videos some time ago, and somewhere he said he runs kerosene/oil for fuel rather than diesel. One thing that surprised me was how he could get the engine to ignite using only a 19:1 compression ratio. I think that's what he said it was. It seems with such a small cylinder volume vs. all the cold metal surrounding it, he'd need more heat/compression to get ignition. But i guess perseverence paid off.