Charlie,

I checked the boxes that the pumps came in and the number is 2P74028.

I missed the "7".  Hopefully that is a good number yet.

Steve

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From: Rotary motors in aircraft <flyrotary@lancaironline.net> on behalf of Charlie England <flyrotary@lancaironline.net>
Sent: Friday, March 17, 2017 2:34:14 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Fuel Pump and Regulator

 

Hey Steve, not to hijack the thread, but which pump is that? I can't find that # on the NAPA web site.

Thanks,

Charlie

On Fri, Mar 17, 2017 at 12:34 PM, Steven W. Boese <flyrotary@lancaironline.net> wrote:

Steve,

I used a stock Mazda 1986 fuel pressure regulator, two NAPA 2P4028 fuel pumps in parallel, and an Andair duplex fuel selector valve. The fuel lines are -6 (3/8") except that the fuel return to one of the tanks has an additional 3 ft of -4 (1/4") aluminum tubing.  The fuel pumps each move 47 gal/hr against a 7 psi head.

The fuel pressure in the rail is 38 psi when either pump is running.  The current draw from either pump is 6 amps.

When both pumps are running, the fuel pressure in the rail is 39.1 psi when the tank without the additional 1/4" return tubing is selected and 39.6 psi when the tank with the additional 1/4" return tubing is selected.  The current draw from both pumps is 12 amps.

Since with my setup running both pumps only increases the pressure by about 1 psi, and the 3 ft of 1/4" tubing only adds about 0.5 psi of back pressure with both pumps running, it might be worth checking for a restriction somewhere in your system.

Steve Boese

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From: Rotary motors in aircraft <flyrotary@lancaironline.net> on behalf of steve Izett <flyrotary@lancaironline.net>
Sent: Friday, March 17, 2017 3:44:46 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Fuel Pump and Regulator

 

Hi Guys

I fired up my secondary fuel pump for  the first time today and was met with what I didn’t expect.
Instead of seeing a blip in the fuel pressure, I had a 10psi increase and high current draw from the pump which blew its 10amp fuse.
I’ll up the fuse as its too low me thinks.

I used an old fuel regulator I had on a rail. It was of a Toyota 4AGE engine of about 135hp.
Seems like its not able to bypass enough fuel with both pumps running.

I think I need to install a higher power adjustable regulator.
What experience do you guys have with turning both pumps on simultaneously?

I’m putting a pressure switch in the circuit to turn on the backup pump if the fuel pressure drops below a preset level.

Appreciate your thoughts and experience.

Steve Izett
Genesis 4 port EC3 EM3 RD1C in a Glasair Super II RG still nearly finished!
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