Reply
 
Thread Tools Display Modes
 
Old 07-15-2011, 09:27 PM   #1
Veteran Member
 
MauleOne's Avatar
 
Join Date: Jan 2011
Posts: 58
Electric Fuel pump Bypass Mechanical Pump

While thinking about installing the electric fuel pump I began to wonder what will happen if my mechanical pump fails and I run on the electric pump.

A problem I have seen with the mechanical rubber diaphram type pump (such as i have now) is that fuel will pass through the rubber diaphram when it ruptures (common mode of failure) and into the engine crankcase.

Of course the only time I saw such a failure was on a gas engine and mine are diesel.

So, with this concern in mind should I plumb my new electric pump with valves and lines to bypass the mechanical pump in the event it fails?

*

Or is this too much of a belt and suspenders solution to a problem that may not exist?
__________________
Advertisement

MauleOne is offline   Reply With Quote
Old 07-15-2011, 11:34 PM   #2
Senior Member
 
Jay N's Avatar
 
City: Edmonds, WA
Country: USA
Vessel Name: WESTERLY
Vessel Model: 1974 Pacific Trawler 37
Join Date: Oct 2007
Posts: 387
RE: Electric Fuel pump Bypass Mechanical Pump

Quote:
DavidM wrote:
Sounds like a lot of trouble for a very low probability failure. But why did you install an electric pump? A rubber squeeze bulb is a better solution for priming.

David
An alternative to the squeeze bulb for priming, is to install one of the Racor filters equipped with the manual pump.

I agree with David, very low probablility of failure.* But you should probably have a backup manual fuel pump as a spare part.* My PO installed an electric fuel pump for priming and manual pump backup, but it has only been used for occasional priming during the past 4000 hours.* Cummins 210HP.
__________________

Jay N is offline   Reply With Quote
Old 07-16-2011, 11:28 AM   #3
Veteran Member
 
MauleOne's Avatar
 
Join Date: Jan 2011
Posts: 58
RE: Electric Fuel pump Bypass Mechanical Pump

I brought the boat up from Seattle to Alaska a few years ago and plan to make the reverse trip soon back to Seattle.

A truely great trip.

As part of my planning I want to back up failure areas.

While I am aware that this is a low failure area it is still one that I have seen in high time trucks and the pump is the same.

Part of the problem is that the mechanical fuel pump can not be changed unless the exhaust manifold is removed. It makes a simple job into a major job. Not something that can be performed at sea.

It is all just a thought right now, thanks for the responses.
MauleOne is offline   Reply With Quote
Old 07-17-2011, 05:22 AM   #4
Guru
 
motion30's Avatar
 
Join Date: Jan 2010
Posts: 740
RE: Electric Fuel pump Bypass Mechanical Pump

the elc pump is handy when changing filters and if you ever run the motor out of fuel on the ICW under a bridge in south florida.......or so I have heard
motion30 is offline   Reply With Quote
Old 07-17-2011, 07:01 AM   #5
Guru
 
JohnP's Avatar
 
City: Toms River
Country: USA
Vessel Name: D U E T T E
Vessel Model: 1996 36' Island Gypsy
Join Date: Dec 2009
Posts: 1,109
RE: Electric Fuel pump Bypass Mechanical Pump

I use a simple electric fuel pump for priming and sometimes fuel transfer.

I could use it* if my fuel pump failed, but I would have to rig a bypass hose,

Could be done,* but hope never to have to.

JohnP
Attached Thumbnails
Click image for larger version

Name:	paint2.jpg
Views:	124
Size:	101.4 KB
ID:	6700  
JohnP is offline   Reply With Quote
Old 07-17-2011, 05:10 PM   #6
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 2,740
RE: Electric Fuel pump Bypass Mechanical Pump

Quote:
motion30 wrote:
the elc pump is handy* if you ever run the motor out of fuel on the ICW under a bridge in south florida.......or so I have heard
*Also handy in the Harlem River
jleonard is offline   Reply With Quote
Old 07-19-2011, 02:30 PM   #7
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
RE: Electric Fuel pump Bypass Mechanical Pump

Quote:
JohnP wrote:I use a simple electric fuel pump for priming and sometimes fuel transfer.
*Very sanitary looking installation, nicely done.

The only thing I might do differently is to closely couple the pump*to the valves*with*tubing rather than hose. *
RickB is offline   Reply With Quote
Old 07-20-2011, 04:27 AM   #8
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,530
RE: Electric Fuel pump Bypass Mechanical Pump

"Part of the problem is that the mechanical fuel pump can not be changed unless the exhaust manifold is removed. It makes a simple job into a major job. Not something that can be performed at sea."


A failed mechanical pump might allow fuel into the engine if pressurized.Or just flow out a failed diaphram into the engine space.

A mechanical pump by pass might make sense for offshore or the belt and suspenders folks.
FF is online now   Reply With Quote
Old 07-26-2011, 03:40 PM   #9
Veteran Member
 
botemon's Avatar
 
Join Date: Oct 2007
Posts: 38
Electric Fuel pump Bypass Mechanical Pump

Part of a fuel polishing system I designed / installed included an electric pump. It's configured for polishing, transferring from one tank to the other, and plumbed it in Parallel (not in series) with the lift pump to keep the engine running in case the lift pump failed. I did use the electric pump during an offshore lift pump failure. It got me through just fine. Sometimes I also use the pump to move the fuel if the boat has been sitting for a long time...prime / bleed injector pump etc.
Good luck!


-- Edited by botemon on Tuesday 26th of July 2011 03:41:21 PM
botemon is offline   Reply With Quote
Old 08-01-2011, 11:59 AM   #10
Veteran Member
 
MauleOne's Avatar
 
Join Date: Jan 2011
Posts: 58
RE: Electric Fuel pump Bypass Mechanical Pump

Nice idea
__________________

MauleOne is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lehman 120 Part-New RAW WATER PUMP drive for original Jabsco Pump JohnP Classifieds 3 03-18-2012 07:27 PM
fuel injection pump septembre Power Systems 2 08-09-2011 06:48 PM
Racor Vacuum Gages and Electric Fuel Pump MauleOne Power Systems 11 07-17-2011 11:05 PM
Fuel injector pump awpptdt Classifieds 0 01-07-2011 07:26 PM
Fuel injection pump REBUILD ralphyost Power Systems 31 11-22-2010 12:04 PM




All times are GMT -5. The time now is 06:16 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012