“The plumbing on an aircraft engine would have to be very good indeed for this failure mechanism to not be the prime feature in forced landing statistics.”
The 912 range is water cooled and has the best reliability of any engine in its class. It has other modern advantages like solid-state ignition etc. coolant problems are very low on the problem list most have been related to bad coolant mix, rather than pipe failure. Trust me, if I can install one it can not be that hard! Rotax are also working on a range of large hp engines, which will also run on mogas.
Rod1