zz28zz

Anyone running elec pumps to back-up their mechanicals?
I'm wanting to do this and I'm curious how it should be configured.

compedgemarine

need to know more about what you have and why you want to do this. I have run 1200 hp engines on nothing but a mechanical pump with no problems. I did have an electric as a backup but never needed it.

MILD THUNDER

iTrader: (3)

I personally don't care for it. In todays market, we have pumps to suit the needs whether it be a single electric or single mechanical.

Kidnova

I was up against the same decision 4-5 years ago after my 557 build and considered mech/elec combo. Decided it was too much BS and went with a mechanical marine CV products on the advice of someone with experience with the CV. Bolted right up to the sea pump and works just fine. Simple and affective, can't beat that.

MILD THUNDER

iTrader: (3)

I agree. I heard the argument on having a electric as a backup in case you lose the mechanical, but, I think that's a bit over cautious. Might as well keep a spare starter, distributor, camshaft, water pump, and ignition switch on board then too lol

Kidnova

Hey watch it mister, I'm the over kill type....I keep a tow line in the boat and always bring my cell phone !!

MILD THUNDER

iTrader: (3)

Ha, I know some guys who keep a spare bravo in their pickup bed at all times!

Kidnova

Bravo failure to me = switch over to my spare... 12 ft Mirrocraft with scream'n 9.9 Johnson on the back and a couple of fishing rods.

zz28zz

My concern is if I loose some fuel press on an extended high speed run, eng would go lean and I might not know until the damage was already done. It's happened once to this boat (before I bought it) and I don't want it to happen again.

It's not for capacity per se, but more for an automatic back-up.

compedgemarine : was your elec pump set to automatically come on, or did it require user action to activate? How was it plumbed into the sys?

I hear what you guys are saying abt carrying around spare parts and I agree, especially with the Fountain where storage space is limited.

Here's a crude drawing of what I have in mind. System would run on mechanical pump normally, but if fuel press dropped while eng still had oil press, the elec pump would come on automatically. I would add a warning light at the helm to indicate I had switched over to elec. Could also add a push button LOP bypass switch to prime carbs if needed.
I know the diagram looks busy but don't think it would look so bad once installed.


[ATTACH=CONFIG]502256[/ATTACH]

MILD THUNDER

iTrader: (3)

HOLY FUK man. Let start with the basics. For starters, what are you running for power? My guess, is a 29 Fever, its nothing that's gonna require something as involved as that drawing.

A quality mechanical pump, like a six valve style with 1/2 NPT in/out, will support 800HP without breaking a sweat. Key is proper fuel line size, and pickup size in tank, etc. Many times fuel delivery issues aren't the pump itself, but the plumbing. Keep it simple bro.