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Facet Fuel Pump

T

TerryWighs

Well Known Member
In looking at the instructions for wiring installation of the faucet solid state electronic fuel pump (RV-8), the instructions strongly recommend installing an oil pressure switch in conjunction with fuel pump??? This concept confuses me a bit. I have a oil pressure switch tied in to the hobbs meter and a red low oil pressure light indicator. Is this that important to install with fuel Pump?
 
The idea is if the engine looses oil pressure, the fuel flow is shut off, thus preventing major damage by running the engine without oil.

This is for an aircraft without a mechanical fuel pump of course.

I would suggest if you do this, that you put in an override switch, as there are times where it may be nice to have the option to totally trash the engine and make it to a safe landing area, not being forced to accept whatever fate serves up.
 
.... It is also intended to stop the fuel flow in the event of an engine stoppage, as in a crash or flip over situation. Allan...:eek:
 
TerryWighs said:
In looking at the instructions for wiring installation of the faucet solid state electronic fuel pump (RV-8), the instructions strongly recommend installing an oil pressure switch in conjunction with fuel pump??? This concept confuses me a bit. I have a oil pressure switch tied in to the hobbs meter and a red low oil pressure light indicator. Is this that important to install with fuel Pump?
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The way you verify the Facet pump is functioning properly is to switch it on prior to engine start and make sure it develops rated fuel pressure. You then turn it off and start the engine with the mechanical pump which verifies its proper operation.

How ya gonna do this when the Facet is wired through an oil pressure switch? :)

Don't wire the Facet pump via an oil pressure switch. You want only a simple on-off toggle switch that is wired to the aircraft bus. An indicator light for the Facet pump is a nice touch, however.
 
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Adding fuel to the fire...

Allan is right. This is more about a running fuel pump in a crash than saving an engine.

A push-button bypass would allow pre-flight check.

Dkb
 
Sam is right. Your pre-crash checklist should include killing the master switch and that takes care of the fuel pump too. If you don't see the crash coming.....well too bad.
 
comfortcat said:
Allan is right. This is more about a running fuel pump in a crash than saving an engine.

A push-button bypass would allow pre-flight check.

Dkb
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There may be some pumps wired through an oil pressure switch, but in the 15 years I've been associated with RVs I have never seen one. Haven't seen it recommended or discussed on any RV forums, either...until now.

I doubt it is the norm with certificated aircraft. The only time I've seen fuel pumps wired via an oil pressure switch is in race cars. You usually don't have time to switch off the master before the car gets rekitted.......
 
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Thanks Sam, You get what I am talking about. It is my understanding that the faucet pump does not run continuous after start up procedure and that the mechanical pump on the engine draws the fuel. Does anyone turn the faucet pump on and leave it on as an auxillary during takeoff and landing??? Regarding precrash list.....that is what the fuel cut off valve is for, as well as turning off Master. Instructions that came with the pump still make no sense at all???
 
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Sam: Your mention of car racing is probably the answer. There is reference to installing on cars as well, in the instructions. I bought this pump through Vans.
 
....I actually always use my boost pump for take offs, landings and go a rounds. The number one issue with power losses is fuel starvation and this is a little extra, easy insurance. Allan...:)
 
TerryWighs said:
Thanks Sam, You get what I am talking about. It is my understanding that the faucet pump does not run continuous after start up procedure and that the mechanical pump on the engine draws the fuel. Does anyone turn the faucet pump on and leave it on as an auxillary during takeoff and landing??? Regarding precrash list.....that is what the fuel cut off valve is for, as well as turning off Master. Instructions that came with the pump still make no sense at all???
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Terry,

Standard procedure with a low-wing aircraft is to always run the aux pump during takeoffs, fuel tank changes, and landings/pattern work. Ops at low altitude should have the fuel pump running because there is precious little time to work with if the mechanical pump fails.

The procedure I described above will allow you to verify aux pump operation prior to taxi. Leave the pump off during taxi so any problems with the mechanical pump will be apparent. But turn the boost pump back on for takeoff in case the engine pump goes out to lunch at low altitude. Once you have left the pattern you turn off the aux pump. I think the POH for my old Warrior called for boost pump anytime below 1000' AGL.
 
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TerryWighs said:
Thanks Sam, You get what I am talking about. It is my understanding that the faucet pump does not run continuous after start up procedure and that the mechanical pump on the engine draws the fuel. Does anyone turn the faucet pump on and leave it on as an auxillary during takeoff and landing??? Regarding precrash list.....that is what the fuel cut off valve is for, as well as turning off Master. Instructions that came with the pump still make no sense at all???
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Terry, This is an automotive pump.... It is designed to be used on an automobile. It is designed to be the only pump to deliver the fuel to the motor. It is designed to replace a mechanical fuel pump on an auto.

Therefore, the instructions have you install a switch to shut off the fuel pump if the motor is not running. Like in an accident. It really should have an impact switch.

None of this applies when we install this automotive part in our experimental aircraft. Just wire it like Van's instructions.
 
Sam Buchanan said:
Terry,

Standard procedure with a low-wing aircraft is to always run the aux pump during takeoffs, fuel tank changes, and landings/pattern work. Ops at low altitude should have the fuel pump running because there is precious little time to work with if the mechanical pump fails.

The procedure I described above will allow you to verify aux pump operation prior to taxi. Leave the pump off during taxi so any problems with the mechanical pump will be apparent. But turn the boost pump back on for takeoff in case the engine pump goes out to lunch at low altitude. Once you have left the pattern you turn off the aux pump. I think the POH for my old Warrior called for boost pump anytime below 1000' AGL.
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^^^ Exactly right. In 1981 Rutan specified Facet pumps on LongEZ's and although I haven't seen them all, I've seen hundreds of 'em and never seen an EZ with the Facet pump connected through an oil pressure switch. I would never add another potential failure point in the fuel system by wiring the electric boost pump through an oil pressure switch.

dk
 
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