Modern piston knowledge gives Britain two aircraft generations before war

What could the Royal Navy do with modern piston-engine technology supplied in 1935?

Build faster reliable small craft and develop two generations of much more capable naval aircraft before the war.

The immediate naval applications would include faster, more reliable motor torpedo boats and much stronger aircraft engines. Power density matters, but reliability matters as much as headline speed. Introducing the knowledge in 1935 leaves time for an initial aircraft generation around 1936. Industry can then absorb its lessons into a second generation ready as war begins, multiplying the effect beyond a single prototype.