I’m working on fuel system for Starduster restoration with an O-360 reconfigured for Bendix Injection. I thought I knew what the “industry standard” was (serial configuration with filter>>boost>>mechanical) but when I started trolling the interwebs to confirm this I found anything but. What I found is summarized in the attached sketch. The “as-built” was for a PS5 pressure carb and possibly irrelevant. The others should be all injected lycomings.
Interested in the thoughts from this group.
Thoughts I had
I know some of you are already thinking “boy, you have a bad case of OCD” and “don’t worry, be happy, ignorance is bliss.” What can I say except there is snow on the ground and the ceilings are 1000’ and I have way to much time to think.
Interested in the thoughts from this group.
Thoughts I had
- On the serial setup isn’t there a failure mode where the boost pump implodes and takes out the downstream mechanical pump. Or where the mechanical pump diaphragm fails catastrophically so that the boost pump cant develop pressure at the servo? Perhaps the small orifice in the mechanical pump vent line prevents the latter. A parallel configuration seems more robust for these failures but does require a second fuel line firewall to engine.
- What does the pressure relief at the boost pump really buy you. I don’t want a boost pump that cant handle running dead head for even a short interval and the only time it actually runs dead head is during priming. Even at idle there is some fuel flow. If vapor lock is my concern don’t I want to cycle fuel through the entire loop up to and through the servo?
I know some of you are already thinking “boy, you have a bad case of OCD” and “don’t worry, be happy, ignorance is bliss.” What can I say except there is snow on the ground and the ceilings are 1000’ and I have way to much time to think.
