Boost Pump Selection

We have installed 8 years ago the 12V Facet Gold Flo pn 478360 as per Tecnam reccomendation (we own a Tecnam P92). See enclosed document and picture. I'm not sure of the connections size (they mention 5/16 fittings) but never had a flow problem. Although generaly fuel pressure from the mechanical pump is OK, on hot days we get extra confidence having the electrical backup.

Hi Gideon,

Nice simple engine installation - thanks for the photo.

Your "Facet Gold Flo pn 478360" does not appear on the Facet list of pump( shttps://facet-purolator.com/specifications/). You may want to check that part number again (should be able to find it stamped on the pump mounting plate).

I am intersted in your oil cooler orientation - looks to be mounted upside down - have you ever had air purging issues?

The Facet 478360E pump is rated at 20gph at 8psi and 45gph at open flow.
The engine uses well less than 10gph at WOT so 20gph is more than needed.
ANY Pressure is OK as long as can keep the Carb bowl full without overwhelming the float valve.
The fuel pressure at the carb is not significant as the carb bowl is under a slight vacuum.

If you are worried, disconnect the fuel hose to one carb and direct it into a quart jar.
If the facet pump can fill the jar in Under 90 seconds, it can deliver More than 10ghp.
Don't be surprised if the jar is full in under 30 seconds.

Fuel pressure is measured as a substitute for Fuel flow because the two are proportional and pressure is much easier to measure.

Hi Gideon.

I could not help but notice your oil cooler installation will encourage the formation of an air  pocket in the top of the cooler which cant be cleared.

I personally would review the plumbing of this installation.

Regards.....Chook.

(This is my second go at posting my response:)

I have just had the following Rans RV-12 boost pump recommendation brought to my notice:

https://www.vansaircraft.com/wp-content/uploads/2018/12/Notification-2018-07-12.pdf

The RV-12 recommended Facet Cube, PN 40135, delivers Pressure Max/Min 7.0-4.0 psi and 32GPH (US) .

This is well above Rotax recommended Max 4.5 psi

https://facet-purolator.com/specifications/

The RV-12 story mirrors, my Sonex/912ULSe low fuel pressure warnings, I have been experiencing on climb out.

What say our Rotax expert???