[tectweaker]

Any recommendations for a fuel cap without a vent for a RV3 fuselage tank with a pressure and/or tight fit?

Something suitable for basic acro and inverted flight.

I used the shaw plug from spruce and the rubber gave up within a month. Otherwise it was perfect for my head. http://www.aircraftspruce.com/catalog/appages/thermos.php

Any other products that can be used?

 

[David Paule]

Van's deluxe locking cap is a nice cap and it's non-vented. It can be left unlocked but still latched if you want. Its basic tightness can be adjusted.

Both of mine leak through the stem, though. So you might prefer one that doesn't have a center locking tab, because the stem is a leak point.

Dave

 

[WingsOnWheels]

The standard Vans cap is not vented. I don't know if they used the same cap on the RV-3, but maybe yours just needs some new O-rings.