Two Carbed Motors Off One Electric Fuel Pump??

[Instigator]

Converting my twin V-6 OMC loopers to electric fuel pumps after internal mods are complete.
I am trageting the 280 HP range (per motor) which equals approx. 28 gph per motor X 2 motors for a total fuel flow requirement of 56 gph @ WFO using conventional wisdom of 1 hp = 1 gph @ WFO
Has anybody done this with a single pump to reduce rigging/pluming/expense???
I can get a Carter or Holley Pump that puts out way more than I need but am qurious if anyone else has done this??
Flow is Flow right??
Thanks guys!
Gary

[Raceman]

Gary, I couldn't image a problem with it, unless you have a carb that's flooding on an engine (needle not seating) and it causes loss of volume to the other engine, but I'd think the volume of those pumps would be sufficient to substain even something like that anyway. Like you said, volume is volume.

If you run Holley (which is my preference) don't forget that pre filtering it is very critical.

[Forkin' Crazy]

OK, so what if the fuel pump fails? Isn't that the reason for two motors? Besides more horse power, but reliability???

One pump, one motor. Got twins on my mind too....:cool:

It ain't as pretty as the under-side of Greg's dash, but I bet he doesn't have a spare relay...LOL!:D

[Instigator]

Thanks Norris and Paul.
Norris I was convinced that that was the wayt to go until I read Pauls reply and now I changed my mind!
Damnit Paul!;)
With the type of boating we do, you hit it right on the head!
Can't believe I had'nt thought of that??
Two pumps it is. Thanks Paul!!
Gary

[Rickracer]

...so that either one or both can supply fuel to either or both engine(s). Double backup. They each have each others back. :D :cool:

[Instigator]

Another great idea!!
Thanks Rick!
If we're in the Bahamas and being chased by pirates:eek: we sure don't want any mohtar problems ;)
Finished grinding on block/case/intake #1 yesterday and should have block #2 done today:D
Internals on their way and hope to start assembling by mid next week.
Let's see---- good intakes X 2 = check, 2.7 heads X 2 = check, ported goodies X 2 = check, big bores x 2 = check, enough parts to build half a dozen gear cases = check, new/used 28" Rakers = check, new/used 28" Choppers X 2 = check!
Would love to make break in/testing at Lake Erie one last time before heading south!
Back to work---see yah!
Gary

[Reese]

you been around the block a few times so I doubt I'll be adding much to the discussion.

I'm not experienced with offshore boats and can only speculate that jumping over waves and crashing back down does nothing good for fuel delivery.

One of the best setups is having the fuel pump at or below the fuel outlet at the tank...now this is damn near impossible in many applications but if you're lucky enough to plumb it this way you'll solve 90% of the problems right off the bat. If that's not possible you'll probably need to run some kind of auxillary/surge tank which only adds more plumbing and complications not to mention I'm not convinced they really help much once you ingest some air.

I would do everything possible to run the pumps as close to the tanks as you can...if you've got two tanks run two pumps, this will keep the distances from the pump to the tank very short.

It's been years since I've used a holley/carter type pump, I prefer using a high volume "in-tank" pump for both cars and boats.

There are three very big advantages:
1) No external pumps, reducing potential leak issues.
2) No need for surge or auxillary tanks.
3) If you happen to ingest some air you'll recover almost immediately because the pump is inside the tank.

The only problem with this system is it's not easy to retrofit on existing tanks, but if you can, I think they are just about bullet proof.

Interesting reading.
Circle track fuel systems (http://www.circletrack.com/techarticles/58518/)

[Brad Zastrow]

Can not think of one good reason to do this. Saves some money, but at what expense. Normally pumps run far more volume than the engine can handle. The big pump you will need can be big bucks. What happens if you lose a motor? Now you are pushing fuel at a dead motor while the other gets you home. Hope the needle seats hold. What if you starve em both? Boom. Rig like every other boat on the planet. Two motors, two pumps.

[Instigator]

top draw tank permanent mount in boat.
I'll mount two seperate pumps w/regulators in the bilge with switches on the dash. This will also eliminate having to lift seat cushions to get to the damn primer squeeze bulb too!!

Brad, I have decided (as already stated above) to go with two but the reasons for one are 1/2 the rigging, 1/2 the money and 1/2 the needed space.
A $60. electric Carter pump supplies more than enough volume to handle two motors.