bringing my total to 30, mainly whilst testing aircraft
I think this record has already been done to death in some other forum but if I had 3 never mind 30 engine failures I would give up flying and take up knitting.
For a moment I thought you must be flight testing lawn mowers but actually my £600 Husquarna is not that bad - only one engine failure in 10 years.
There seem to be some sections of the GA scene where massive engine failure rates are indeed common, and readily accepted. I don't fly behind a Rotax but only in recent years have they elevated themselves from that category. This is (to me) completely unacceptable because it makes a plane totally useless for going anywhere, due to the risk of coming down in water, in a forest, on a mountain, and even if I carried a parachute, what about passengers? They have a reasonable expectation of some kind of safety.
The MTBF of the certified Lyco/Conti engines is of the order of 50k-100k hours and the vast majority of pilots will never get a failure in their flying lifetime.
Sure you train for a forced landing, and you do the usual escape routes (a life raft, etc) but with an MTBF of say 1k-2k hours (probably about the mark for the Thielerts) GA would totally cease to have any value for going anywhere.