This is something that I have noticed about my -8 for some time, and have been meaning to post - but I always forget by the time I get home from the airport....I think it is peculiar to the -8 because of the under wing NACA vent - not sure if any other models share the same configuration.
I usually fill up with gas at a field a short distance from my home base, and always feed from the left tank for the short return trip. I sometimes have noticed a faint smell of fuel when I turn base to final for landing, and after the first time, I did a little investigating to make sure I didn't have a problem. What I discovered was that it was stronger with the passenger vent open, and almost went away when the passenger vent was closed. It also didn't happen at all if I fed fuel from the right tank on my return.
Putting these little pieces of info together, I surmise that with the tanks freshly filled, and the right tank isolated (not being used), I am getting a "burp" of fuel out of the vent. When I turn make the pattern turns, I must be getting a little plume of fuel vapor, and it is going under the wing and into the under-wing NACA scoop. (Now before anyone gets too worried, I've been a fireman for many years, and I can tell you that this faint smell is WAY below flammability limits. It's just enough to notice.)
Anyone else smelled this? Any alternative theories? the conditions I've stated are the ONLY times I've noticed it, and only in a left-hand pattern (you don't get it with right turns, and since the scoop is on the right, that's why I think my explanation makes sense...
Paul
I usually fill up with gas at a field a short distance from my home base, and always feed from the left tank for the short return trip. I sometimes have noticed a faint smell of fuel when I turn base to final for landing, and after the first time, I did a little investigating to make sure I didn't have a problem. What I discovered was that it was stronger with the passenger vent open, and almost went away when the passenger vent was closed. It also didn't happen at all if I fed fuel from the right tank on my return.
Putting these little pieces of info together, I surmise that with the tanks freshly filled, and the right tank isolated (not being used), I am getting a "burp" of fuel out of the vent. When I turn make the pattern turns, I must be getting a little plume of fuel vapor, and it is going under the wing and into the under-wing NACA scoop. (Now before anyone gets too worried, I've been a fireman for many years, and I can tell you that this faint smell is WAY below flammability limits. It's just enough to notice.)
Anyone else smelled this? Any alternative theories? the conditions I've stated are the ONLY times I've noticed it, and only in a left-hand pattern (you don't get it with right turns, and since the scoop is on the right, that's why I think my explanation makes sense...
Paul