fuel electric and mechanical
 

electric and mechanical fuel pumps. DONT BASH MY DRAWING lol

i dont believe you can pull through a electric with a mechanical. my question is should i tee in off of the pickup with both elec and mechanical. if so where do i run the electric OUT to? should it feed before the mechanical to the in side of the mech pump before or after the seperator
https://cimg6.ibsrv.net/gimg/www.off...145733a05d.jpg
. i want both for back up purpose and priming. it is a race boat

a single mech will easily handle 800hp keep it simple

Don't fully understand what your trying to do, but will say you don't want to Tee from same pickup without having a fuel shut off. Without a shut off the pump will draw from tank and from other pump

how do ya prime it? what happens if it fails. i have 2
power steering pumps y not 2 fuel

Mech pump doesn't need to be primed and in most cases electric doesn't either if the pump is below the fuel pickup.

[QUOTE=AllDodge;4849670]Mech pump doesn't need to be primed and in most cases electric doesn't either if the pump is below the fuel pickup.[/QUOTE

the tanks are under cockpit floor i was going to use elec to pull up from the tank and push to separators,then from separators to mech pumps on engines the mech will be slightly lower then tanks.

I would just put a quality electric pump as close and as low as possible in relation to the tank and call it a day.

Ayuh,..... Fuel pumps, Any fuel pump, should only pump Filtered fuel,......

I too, don't understand why yer tryin' to complicate a fairly simple thing,.....

Most boats sit in the water, stern low, so the mechanical pumps will be below the fuel tanks anyways,..... If yer on the wagon, crank up the tongue jack,....
'bout the only strain on a fuel pump, is suckin' through the anti-siphon valve on the tank,.....

I ran close to 1000hp with mechanical pumps and never had a single failure of a fuel pump.

When I bought my Top Gun years ago, it had a couple of warmed over big blocks. When I went to look at it, it had two electric fuel pumps in the bilge & mechanical pumps on the motors. I questioned it & the owner said he bought it that way & didn't use the electric pumps since one had stopped working & the motors ran fine without them. After I bought the boat, I ran it & it ran great, so I just removed the electric pumps. It was set up that the mechanical pumps had to pull fuel through the electric pumps. It also had boost gauges in the dash so i knew it had bigger motors in it at one time. The dash was wired & had what appeared to be factory switches for the pumps.