Good question on plugging the intake / exhaust; I have not been doing so. I'd be interested in thoughts on whether it would make a big difference. I certainly don't hear any air leak / movement when I listen at either spot. I suppose having the throttle closed counts some for the intake. The aquarium pump isn't moving huge volumes, either.
KUMP - Indianapolis, IN / KAEJ - Buena Vista, CO
RV-10 N410TS bought / flying
RV-8 wings / fuse in progress ... still
1948 Cessna 170 N3949V