14-19-3 Fuel Tank Vents & Caps

Rob58

Rob58

Moderator
As some of you know the -3 that I recently purchased had an in-flight power loss. Power was quickly restored with the boost pump; landing uneventful. This prompted me to purchase a complete fuel system kit from Continental (picture below), which I am in the process of installing. Nine engineering revisions were made between the original pump design and what TCM sells now (not that this means the current design is better!). However there is one area of the fuel system that I have little knowledge about: the tank venting system and the fuel caps. Is all of the venting done through the caps? Can that be a problem? Should I replace the caps? Hoping that someone familiar with the -3 can bring me up to speed on this. I would sure hate to learn that the original problem was with the venting, although I am very satisfied to have all new stuff pumping gas into the cylinders. Thanks for any feedback!
 
Rob, all fuel caps are vented so make sure yours are working. On my -2 there is just a straight hole in the middle of each cap. Can't get any simpler I guess. It's always the simple stuff that causes the problem finding it is hard at times. Looks like you went for the juggler on this but being all new gives a certain piece of mind. I had a major oil leak on a Navion once and spent all sorts of time and money. Turned out to be the tach shaft gasket ----75cents! Lynn the crate :D
 
Hi Lynn, thanks for your reply - helpful as usual! I like simple and will verify the holes in my caps are free and open. Since I have stepped into the world of the fuel injected engine I have learned just how much more complex the entire system is over the carbureted 470 in the -2. A lot more things to go wrong and the initial pressure setup requires knowledge, experience and some rather expensive gauges. I did not want to take any chances with a component failure and the peace of mind that came with the new parts made the dent in my pocketbook less painful. Coupled with all of the historic problems with the nosegear in the -3s this has been a challenge to my nerves all the way around. Stay tuned as my saga continues... Rob
 
Comparing my -3 and Russell Williams' -2, I have both vented caps and a vent line that vents below the wing or fuselage. Russell has just the vented caps. At least on my -3, the wing tanks have two vents under the wings; one to drain out the indent the cap sits in and the other to vent the tank. Who knows when Bellanca changed the design, since mine is towards the end of the -3 production.
 
Good info Brian - thanks very much. I will check for an underwing vent on my plane. I've read many comments on the Viking forum and elsewhere about problems with tank venting, using the wrong type fuel cap and related issues. This is what prompted my question.
 
I'm going to hope the pilot that suffered the engine problem switched the tank selector at least once... that would rule out vent blockage since it's highly unlikely that TWO caps would clog at the same time.

I can understand your scorched-earth approach to the problem. I had a power-loss event at 6000 ft that I rode to the ground with less than acceptable result :) Don't fear the IO, like everything in life, once you learn it, it's easy and MAN, it'll walk away from a -2.
 
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