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I figured enough folks have had problems with facet pumps that this subject would be better in the open discussion area.
I'm still building my Cruzer, yet I'm at the point where "systems" are starting to be added. I purchased the Zenith complete FWF kit for the O-200.
The plans show the facet pump mounted on the engine side of firewall with only a single line. It seems that popular opinion says I should install a check-valved bypass around the aux facet pump just to provide an unobstructed fuel flow if the pump failed and blocked the outlet.
I don't want to re-invent the Zenith design. Has anyone placed the facet pump in the cabin, in front of the center console, with a tee before and after the pump to allow a second line?
Pics would be great if any are available. Thanks!
High Carl, do you need a fuel pump? I am not planning on installing one on my O-200.
Thanks, Steven, but mine came with the FWF package...
If I may ask, I know you're also using an O-200; are you going to run an aux pump or rely completely on gravity?
PM me if you'd prefer...
My C150 has an O200 with no pump. Just gravity. 1966 with 4000+ and never had an issue with that. I don't think you need one. Call Zenith but you are just adding complexity and failure risk. Simple is better in aviation...... On my Ch650B I have 2 faucets pump. No choice it's a low wing but would prefer avoiding it.
From the start of my build, I have planned on not having a pump at all. Agreed, more complexity with the pump. I will do an extreme angle fuel flow test and make my final decision, and I can easily add a pump afterwards if I decide to.
Want to share one event I experienced. I’ve got a C-90 on my 750, gravity fed, no fuel pump. Very basic, simple set up, the way I like it. In 2017 I was relatively low on fuel, but easily had an hour to spare. Was almost home, but wanted to look at an area below in more detail. I set the plane up with 3/4 flaps, slow flight, around 50 mph, very high-nose attitude, approximately 500’ agl. I stayed in that configuration for 3 or 4 minutes, was ready to leave, went full throttle & retracted the flaps. Within seconds I had an engine out. I picked the closest clear field and commited to landing the plane with no plans to try to restart, as I was so low to begin with. I made a fairly routine landing except for the adrenaline I had flowing thru my body.
After checking the obvious suspects like water in fuel, gascolator screen, fuel in tanks, etc., I cranked the engine and it fired right up. Even though I knew I had close to 7 or 8 gallons of fuel, I called a buddy to bring me 5 gallons of gas. 2 hours later I took off from the field with the plan to run the engine at full power circling overhead to confirm she’s going to run, and proceeded on to my home base airport.
After reviewing all that happened over the next week or so, I figured out I had un-ported my carburetor by flying in such a high angle of attack that I got the carburetor above the level of fuel in my tanks. Being gravity fed, I fuel starved the engine. Lesson learned, I don’t loiter in slow flight for long, and when I do it’s only with close to full fuel. I never installed a fuel pump, even though it would be pretty easy to put a Facet pump in place. I’m glad to share this information so others can learn from it. I certainly have. We all make mistakes, and sometimes we get lucky.
Thank you for sharing that experience Jimmy. I would love to sit down and hear that story with you sometime! You made solids decisions and kept yourself safe. Awesome.
It seems that most are using a fuel pump. Reading your experience makes me take a deeper look into what I am going to.
Steven, now that you've read Clint's in-depth report below, how do you feel. I'm thinking no pump at this point since I have a Cruzer and will not (should not) have the STOL-like attitudes during climb-out or slow flight.
I was a bit concerned beforehand since the Facet -105 pump supplied in my FWF kit from Zenith is somewhat less than a 3/8" pass thru, and I was concerned about the restriction. I will start with no pump but have wiring and space in place in case I need to retrofit.
Very good information, Thanks for sharing this!
I had a few issues during flight test too, not quite as exciting as yours though! Here is a link to a write up I created. It's a bit wordy, and not very refined, but might be interesting to anyone planning to use a facet pump as part of a gravity feed system.
Wow, Clint, that is a very thorough evaluation and test of your fuel system! An interesting read and says something about how your airplane is built. I would ride in your airplane anytime.
Thanks Joe! That is a very high compliment coming from a guy like yourself. I saw your plane at the Zenith Open House, what a great looking aircraft! My right seat is open for you anytime.
Clint, now that I've read your report 3 times, I sincerely thank you for taking the time to report, as well as the thoroughness of your investigation. You really checked out all (?) possible areas of restrictions, check valves, and bubbles! This report should be required reading for all 750-x builders!
Thanks Carl, when the weather warms up I hope to do a few quick tests on the andair fuel selector too, not expecting many surprises but I'd like to complete the data for the entire system.