Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 28-01-2015, 05:58   #1
Registered User
 
Snowpetrel's Avatar

Join Date: Jul 2012
Location: Hobart
Boat: Alloy Peterson 40
Posts: 3,071
High diesel filter location or header tank

Hi,

I am just installing my primary filter. The most convenient place to put it is under the bridge deck above the engine. This means the body of the filter is about 1 foot above the engine, giving me room to get a container under it to catch any diesel when changing it or draining the glass bowl.

Is there any issue with the extra head of pressure it might put on the fuel in the engine supply line, and is it possible that it might drain through the injector pump and injectors or return lines into the cylinders and hydraulic the engine? I guess a header tank has the same potential issue if the fuel shutoff valve is left open?

Any thoughts?

Cheers

Ben
__________________

__________________
My Ramblings
Snowpetrel is offline   Reply With Quote
Old 28-01-2015, 06:28   #2
Registered User
 
S/V Illusion's Avatar

Join Date: Oct 2007
Location: Lakewood Ranch, FLORIDA
Boat: Alden 50, Sarasota, Florida
Posts: 1,692
Re: High diesel filter location or header tank

not an ideal location for a number of reasons. One consideration you may have overlooked is that placing it higher than the tank level is that it makes filling more difficult when you change the filter. Gravity is your friend.
__________________

__________________
S/V Illusion is offline   Reply With Quote
Old 28-01-2015, 06:36   #3
Registered User

Join Date: Mar 2014
Location: Canada
Boat: 1971 Irwin 37cc
Posts: 39
Re: High diesel filter location or header tank

I don't know of many (any) boats were the tank is above the engine to allow gravity to help. The primary filter should be placed before the engine fuel pump so it will be working on vaccum, pressure is after the engine fuel pump and excess fuel is returned to the tank.

John
__________________
John Boor is offline   Reply With Quote
Old 28-01-2015, 10:38   #4
Registered User
 
Terra Nova's Avatar

Join Date: Apr 2007
Location: Marina del Rey, California
Boat: Freya 39 cutter- Terra Nova
Posts: 3,645
Re: High diesel filter location or header tank

You don't want to make the lift pump's work unnecessarily difficult.
__________________
1st rule of yachting: When a collision is unavoidable, aim for something cheap.
"whatever spare parts you bring, you'll never need"--goboatingnow
"Id rather drown than have computers take over my life."--d design
Terra Nova is offline   Reply With Quote
Old 28-01-2015, 11:23   #5
Registered User

Join Date: Mar 2014
Location: Canada
Boat: 1971 Irwin 37cc
Posts: 39
Wink Re: High diesel filter location or header tank

My filter is above the lift pump by actually 12 ins. When I replace my filter I open the drain cock at the bottom of the bowl then crack the top of the filter housing allowing a small amount of fuel to drain (about 2oz) close the drain cock , removeing the old filter slowly and replace with new one slowly then turn on the ignition (I have an electric fuel pump) allowing the fuel to flow through the system and purging the small amount of air in the top of the filter. My Westerbeke 4-107 came with a mechanical lift pump and I would purge the line with the lever on the pump after opening the bolt on the engine filer housing until no bubbles can be seen. I believe that once the lines have been purged of air the lift pump does not work any harder at above, level, or below the pump.
__________________
John Boor is offline   Reply With Quote
Old 28-01-2015, 11:44   #6
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 6,385
Re: High diesel filter location or header tank

Quote:
Originally Posted by John Boor View Post
I believe that once the lines have been purged of air the lift pump does not work any harder at above, level, or below the pump.
If the pump is sized correctly, that is correct.

Put the filter where you can get to it easily and drain it. You mentioned that in your OP, but right above the engine doesn't sound good at all to me, 'cuz if you need to change the filter if it gets clogged and stops the engine, the engine will be hot. A remote location would be far preferred. Our filter is under the head sink adjacent to engine compartment.
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 28-01-2015, 11:52   #7
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: High diesel filter location or header tank

Quote:
Originally Posted by Snowpetrel View Post
Is there any issue with the extra head of pressure it might put on the fuel in the engine supply line, and is it possible that it might drain through the injector pump and injectors or return lines into the cylinders and hydraulic the engine? I guess a header tank has the same potential issue if the fuel shutoff valve is left open?
There is certainly no problem with head pressure and no real way to hydraulic the engine with fuel anyhow.

Our entire fuel tank is well above our engines with no issues. Any increase in head pressure from a small fuel filter will be unmeasurable.

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 28-01-2015, 12:41   #8
Registered User

Join Date: Apr 2011
Posts: 2,243
Re: High diesel filter location or header tank

When you change the fuel filter, you need the fuel in the tank to be higher than the filter, so you can bleed out the air. The lift pump won't help you here, as it is after the filter.

When I change my filter, I have to be careful that the fuel tank is nearly full, otherwise it won't bleed.
__________________
Bristol 31.1, SF Bay.
MarkSF is offline   Reply With Quote
Old 28-01-2015, 12:44   #9
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: High diesel filter location or header tank

Many boats have tanks so low that it would be impossible to mount a filter lower than them. Another poster talked about adding an electric lift pump to help with priming. Alternately, one can put a squeeze bulb inline, or simply fill the primary filter housing as full as possible and bleeding through the secondary filter bleed screw as normal.

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 28-01-2015, 13:19   #10
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,334
Re: High diesel filter location or header tank

Quote:
Originally Posted by colemj View Post
Many boats have tanks so low that it would be impossible to mount a filter lower than them. Another poster talked about adding an electric lift pump to help with priming. Alternately, one can put a squeeze bulb inline, or simply fill the primary filter housing as full as possible and bleeding through the secondary filter bleed screw as normal.

Mark
yeah.. in fact you might even say most boats the tank is lower. (cats excluded!)

I'm not sure I like the filter above the engine though... messy changing filters (all over the engine) , filter problem above the hot engine, engine fire goes right to the filter overhead.... I'd find some other place for it.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 28-01-2015, 13:24   #11
Registered User
 
Terra Nova's Avatar

Join Date: Apr 2007
Location: Marina del Rey, California
Boat: Freya 39 cutter- Terra Nova
Posts: 3,645
Re: High diesel filter location or header tank

Another consideration is to locate the filters where they do not hinder access to engine for service and routine maintenance.
__________________
1st rule of yachting: When a collision is unavoidable, aim for something cheap.
"whatever spare parts you bring, you'll never need"--goboatingnow
"Id rather drown than have computers take over my life."--d design
Terra Nova is offline   Reply With Quote
Old 28-01-2015, 14:03   #12
Registered User
 
Panope's Avatar

Join Date: Sep 2012
Location: Washington State
Boat: Colvin, Saugeen Witch (Aluminum), 34'
Posts: 1,593
Re: High diesel filter location or header tank

I like having some sort of quick drain valve at the low points of the fuel system. A low mounted filter body would accomplish this nicely.

Steve
Panope is offline   Reply With Quote
Old 28-01-2015, 15:01   #13
Marine Service Provider

Join Date: Sep 2014
Posts: 15
Re: High diesel filter location or header tank

You don't want to place the filter that high. If you have any type of air leak the air will be trapped at the highest point. This will cause and air lock

Sent from my SM-N900V using Cruisers Sailing Forum mobile app
__________________
Mr Filter is offline   Reply With Quote
Old 28-01-2015, 16:22   #14
Registered User

Join Date: Feb 2011
Location: South-East Australia coast
Boat: 40ft fibreglass sloop
Posts: 163
Re: High diesel filter location or header tank

Quote:
Originally Posted by Mr Filter View Post
You don't want to place the filter that high. If you have any type of air leak the air will be trapped at the highest point. This will cause and air lock
Isn't that why filter housings have air bleed screws? So it may be better for air to accumulate at the filter where you can easily bleed it off?

But I may be missing something since you, as a filter vendor, will know your stuff - so correct my thoughts here thanks.
__________________
Marqus is offline   Reply With Quote
Old 28-01-2015, 17:37   #15
Registered User
 
Snowpetrel's Avatar

Join Date: Jul 2012
Location: Hobart
Boat: Alloy Peterson 40
Posts: 3,071
Re: High diesel filter location or header tank

Quote:
Originally Posted by colemj View Post
Our entire fuel tank is well above our engines with no issues. Any increase in head pressure from a small fuel filter will be unmeasurable.
Interesting Mark, did you ever shut off the fuel valve? or was it a non issue? I'm most worried about fuel flowing into the engine via gravity and causing major damage. Air will just stop the engine, fuel might destroy it...

Quote:
Originally Posted by Mr Filter View Post
You don't want to place the filter that high. If you have any type of air leak the air will be trapped at the highest point. This will cause and air lock
Good Point. I'm not sure if trapped air is likely to be pushed down the line as small bubbles and back out the fuel return on the injector pump? or will it slowly accumulate until it stops the engine? I guess it would depend on the amount of air. Of course ideally air wont get into the system, but if it does it's nice to have it self bleed back though the return line.

Just to clarify, the filter will be outside the engine box, over the transmission area in a place where it can be easily seen, inspected and replaced cleanly. My tanks are low, and I have no real bilge, so bleeding it via gravity will be only possible if the tank is full, and even then only if I put the filter in a very awkward to reach spot.

But I'm heading back down to the boat today, so I will give it more thought. Thanks for all the input.
__________________

__________________
My Ramblings
Snowpetrel is offline   Reply With Quote
Reply

Tags
diesel, head

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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
Header Tank To Eliminate Saildrive Salt Water Intrusion timbenner Propellers & Drive Systems 18 25-06-2016 11:51
.kap files header r2b2s OpenCPN 5 14-05-2012 10:13
Filter Gasoline in a Racor Diesel Filter ? Sailorman Ed Engines and Propulsion Systems 4 04-12-2011 20:37
Fuel filter location rdempsey Engines and Propulsion Systems 19 02-11-2007 13:01



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 01:28.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.