Now that I've plugged all the holes in the firewall with grommets, the heat
pouring into the cockpit is much reduced. Now the biggest remaining source
is a mild flow of warm air from the heater. I have the heater controls
turned off, but air flows in anyway. Again I'll ask my usual dumb
question, is this normal? If not, what do I need to do? If it is normal,
how can I block off the flow of warm air? Any chance of getting cooler air
from outside vented into the cockpit? Thanks in advance for any advice.