Is this an aircraft engine designed from scratch?
I am no engine specialist but I spoke to a few of them last year, and the consensus was that Thielert's getting 130HP from 1.7 litres was pushing a car engine way beyond its limits. A car engine spends most of its time at 10-30% of rated max power.
We do badly need a decent avtur burning engine but so far there is no sign of one that lasts.