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(1.15.04)
After last summer's nonsense and the pain of spending over $100.00 on Racor
spin-on elements, I spent some time searching Ebay for a cheaper (in the
long run) alternative to our current R24S filter. I was able to find two
new 500FG turbine filters for 75.00 a piece with a much cheaper element--8.00
each vs. R24S at 25.00 each. Now that I've got the filters, I need to determine
the best way to set up the filtration system so that it's possible to change
filters while underway, and maintain a fuel polishing circuit. After a bit
of musing, I came up with the sketch above. This system would utilize all
but one of our current filters, so we wouldn't be wasting any pieces, plus
it allows for an easy way to prime the fuel lines and filters--not to mention
ensuring the liklihood of having an engine when we need it most.
The Walbro pump, located where it is, and the priming pump on the R24 allow
for easy priming on both sides of the manifold (valve). After changing the
filters in the 500FGs, all that is necessary to bleed the system up to the
lift pump is to close the valve located just after the two 500FGs, flip
on the Walbro and let it run for a minute or so. Once fuel has been drawn
through the 500FGs, it's a simple process of opening the valve to direct
fuel to the engine, then operating the lift pump until there's fresh fuel
at the tertiary filter's bleed points--although I doubt that would even
be necessary since there shouldn't be any air between the second valve and
the tertiary filter. Similarly, switching the first valve to the R24, I
can easily use it's built-in pump to prime it. Here's a picture of the pump
I'm after, it's a Walbro 6802, 7 psi shut-off, max. capacity of 60 gph, continuous-duty pump. The pump is often available new through Ebay or through Go2Marine.com for about 100.00.
(1.25.04)
Well, here's what things look like at this point. I only had a couple of
hours on Friday afternoon to begin the layout, but I got the Star Board
cut to size (20"x25")--we were hoping for 25x25, but the scrap
didn't have enough height to get those dimensions--and began mocking-up
the fuel system layout. I've already discovered that the Racors occupy far
more space than I had imagined, and things are going to be pretty tight.
At this point, I'm thinking I'll probaby have to relocate the freshwater
pump, accumulator, and freshwater filter somewhere else--I was hoping to
have room for all of that plus the fuel filter set-up on the Star Board.
Unless I get a bigger piece of Star Board, however, I don't think it's going
to happen. Too bad. The biggest challenge, of course, is mounting things
to maximize space and yet allow easy access to the various valves and filters.
The Star Board is a scrap I picked up from a local marine store--Wolf's
Marine. Even though it's scrap, it's in good shape and cost a pretty penny--Star
Board is not cheap! Here's what it looked like before I cut it.
The Star Board was a cinch to cut on a band saw. I used a flapper wheel
to smooth the edges after making the cuts.
With the piece cut, I laid out the fuel system pieces. It was quickly apparent
that my idea of joining the two 500FGs with a small piece of fuel hose was
too space-consuming. I'll have to find a coupler that will allow me to mate
the two filters together with a minimum of space between them.
I was able to find the necessary brass 3-way valves and hose adapters at
a local hydraulic shop. The 3-way valves are very similar to the Tempo valves
sold at West Marine but half the cost--12.50 apiece vs. 25.00.
After laying things out, I experimented with creating a mount for the 3-way
valves. My initial thought was to use a couple of pieces of Star Board,
but that idea fizzled when I got to thinking that a piece of strap metal
would make a nice, clean bracket. I found a decent piece laying around the
shop and gave it a couple of bends to see how it would work.
The picture on the left shows the contour of the bracket, the one on the
right, how the valve mounts to the bracket. Although this appeared to be
a fairly decent arrangement, I think I like the idea of bending the mounting
flap upward, essentially creating a piece of channel so that the valve bracket
will be hidden behind the valve. Bending up a piece of angle iron, I tried
it out. (I need a bigger and better piece of angle if I'm going to stick
with this method)
I think the idea of bending angle iron is probably the best. Some time this
week, I'll pick up a piece of stock and begin bending up my brackets. I'll
also be returning to the hydraulic supply shop to find some sort of coupler
to link the two 500FGs together.
Here's a picture of all of the systems
that--ideally--would be located on the Star Board (on the starboard side
of the engine compartment). Obviously, there's no way all of this will fit,
so...time to modify the plan.

(1.27.04)
I spent some time last night mulling over the planned layout and ended up
making a few changes. My original idea was to mount all three of the valves
separately, with hoses leading from the filters to the valves, then on to
the tertiary filter or fuel tank (for the fuel polishing circuit). Since
space is at a premium, I decided to mount the three valves directly on the
filters--a valve on both the inlet and outlet of the 500FGs, and the third
on the outlet of the R24S. This idea makes far more sense; not only does
it reduce the number of connections and save space, it also provides a fairly
stable mount for each valve (although I am still planning on integrating
some sort of bracket into the setup to ensure stability).
I found the necessary coupler to tie the two 500FGs together at the hydraulic
supply shop. It makes for a slick installation and drastically reduces space
requirements.
Here are a few pictures of the filter setup as it has evolved--with the
valves mounted directly to the filters.
Compare this to the earlier layout 
(Enlarge photo for explanation
of plumbing)
The valve located between the two 500FGs and the R24S is the manifold that
determines whether fuel is directed through the primary fuel filtration
circuit (500FGs) or the secondary fuel circuit (R24S).
The valve coming off of the left
500FG will direct fuel to the diesel tank (upper barb) for fuel polishing,
or to the tertiary filter (lower barb) for normal engine operation.
On the R24S side, there is the inlet from the tank (on the left) and the
outlet to the engine from either the R24 or the two 500FGs (on the right,
the barb angled down an inlet from the 500FGs; the barb angled toward the
lever, fuel outlet to the tertiary filter).
A simple combination of valves easily isolates the filters for service without
interrupting engine operation. Similarly, with one valve adjustment, fuel
can be drawn from the tank, filtered, and returned to the tank for polishing.
I've got to pick up four more critical connectors before the setup will be complete--I'm hoping to do that this afternoon--and I need to mount the filtration system on the Star Board after double checking clearances and space in the engine compartment.
As mentioned earlier, I'm mounting the
fuel filtration system on the starboard side of the engine compartment.
In addition to the fuel system, I also have to mount the accumulator, freshwater
pump and filter on the same bulkhead. Since there is not enough space on
the board to mount all of those systems, I've decided to mount the systems
separately--filtration system as a unit, freshwater pump, accumulator and
primary filter as a unit, and the secondary freshwater filter as a unit.
The picture below shows our previous layout--minus, of course, the two new
Racors.

(LEFT) The orange-topped piece just visible behind the oil-fill is our old
primary, a Fram C1110PL. (The insulation was an earlier project)
(RIGHT) Another angle, showing the clearance between the engine and bulkhead.
(1.30.04) I purchased
the final pieces for the filter setup, received the Walbro pump, and shot
one last picture of the filters before installation--all the valves tightly
seated and ready to go.
(2.17.04)
It's in. I still need to plumb the fuel lines and the water lines for the
freshwater system - some of which will have to wait until it warms up so
I can actually bend the hoses - but the job is basically done. Layout was
a bit of an issue. Working in such tight quarters necessitated the purchase
of a handy 90-degree drill attachment. With that, the rest of the installation
was a cinch. Here are several shots of the final set-up.
You'll notice the old R24S just above the alternator in the picture, nestled
in below the new Racors and the accumulator. Just forward of the R24S is
the freshwater pump.

I ended up running each piece of Star board through a jointer to get smooth,
clean edges. I then routed a bevel on both sides of the board to eliminate
any sharp edges that might cut into the engine insulation. This Star board
cuts like a charm and looks quite nice with all the edges finished off and
smoothed over. What's not visible in the photos (actually just barely visible
in the bottom left photo) are the pieces of Star board I cut to use as feet
to keep the Star board from completely squishing the insulation. I used
a hole saw to cut the pieces, then heated them up with a propane torch to
mount them to the back of the boards.
(3.18.04) I ran all of the fuel line
to the filters last week and have several pictures of the finished project.
I ended up securing a few of the lines to the Starboard using zip-ties.
I'm very pleased with the result - it looks good and seems quite functional.
Walbro Installation
(3.18.04)
It’s taken far longer than a week to get back to the fuel pump installation,
but it’s finally in – one of the projects I finished up over
my spring vacation. I ended up mounting the fuel pump on the bulkhead just
forward of the diesel tank in the port cockpit locker, where it tucks in
nicely above the tank and provides the most efficient runs for the fuel
line. I considered a couple of other locations in the engine compartment
since I wanted to limit the amount of noise in the cabin while the pump
was running during polishing, but things are already pretty tight in there
with the new Racors and the spaces available would have required extra hose
and complicated runs. Preferring straighter runs and fewer connections,
I figured we could live with whatever noise the pump might produce during
polishing – which shouldn’t be too much of a nuisance since
we probably won’t even be aboard during polishing.
After running the fuel hose, I began thinking about how I wanted to wire the pump. I’d purchased a simple on-off toggle (SPST) by Cole Hersee that I wanted to locate in the engine compartment near the fuel polishing valve, but I didn’t have an easy way to mount it. As I was looking things over, trying to decide where to locate the switch, I finally decided to bite the bullet and pull the dual Racor mounting board off the bulkhead and mount the switch where/how it ought to be located: directly to – or through – the Starboard, just below the polishing valve, so that everything could be reached without completely removing the engine cover. This, unfortunately, required cutting off all of the zip-ties I’d just used to secure the fuel lines and removing the lines from the barbed fittings. I was motivated, though, by the fact that I was doing the job the way it should be done.
With the Starboard removed, I drilled a hole for the switch and confirmed that I would have to rout a recess in the back of the panel for the switch to sit in since its threaded portion wasn’t quite long enough to pass through the board. A few careful passes with my Dremel and a routing bit, and I had created enough of a recess to thread the retaining ring onto the switch. I crimped ring connectors to a couple lengths of 14 gauge wire, attached them to the switch, wrapped the connections with electrical tape to keep them from shorting out against the Mylar insulation, and relocated the panel in the compartment, reattaching all the fuel lines, etc. Voila! I was quite pleased with the installation, and the results were definitely worth the extra effort. (Far better than my original idea of mounting the switch on a plate screwed to the board)
I ran one of the wires coming off of the switch to the electrical panel where I wired it into a terminal bar (something I added at that time) that supplies a constant 12v from the house bank. The other wire ran straight to the positive lead of the fuel pump, of course, with a 5 amp fuse wired in to protect it. I also used a 6 gauge wire as a static ground that I was able to tie into some of the main grounding wires that came from Cape Dory. With that, I turned some valves and flipped the switch. The pump whirred to life and the filters filled with fuel.
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I had to add
a tee to the existing fuel return on the tank for the polishing circuit.
The line coming in from the right is the engine fuel return, the line
from the left is from the Walbro. |
One thing remaining to be sorted out, however,
is the presence of a pocket of air in each Racor 500FG just below the turbine.
I called Racor to ask about this and was assured that it’s completely
normal and doesn’t affect the pump’s performance – something
I find very hard to believe. The Racor technician I spoke with told me that
“you’ll even notice that there’s air in the top of the filter
during operation” – again, something I find equally hard to believe.
When I cracked the lid on one of the filters while the pump was running, fuel
spilled over the top, belying the technician’s claim. At this point
I’m thinking about unbolting the filters and tilting them sideways to
get rid of the air pocket - of course doing this every time the filters are
drained seems completely ridiculous. Perhaps another call to Racor, and another
technician, might explain some things.
(3.23.04)
Another Racor technician - or perhaps the same one, for all I know - assured
me that the pockets of air are perfectly normal. He also told me that the
filters tend to "run down" a bit during operation - i.e., the fuel
level in the filter drops - leaving air space at the top of the filter. When
I told him about my experience cracking the lid and spilling fuel, he said,
"Well, sometimes they run high, and other times they run low." I
guess the best I can do is to tip the filters to dislodge the two pokets under
the turbines and hope it's okay. We shall see.
(9.25.04)
This could have been added months ago, but I've just been far too busy. The old Perkins fired right up on launch and the air pockets present in the 500FGs haven't caused us any problems. Apparently the Racor tech knew what he was talking about - go figure. The filtration system has worked marvelously. Long before Ariel ever went in the water for the season, I had the fuel polishing circuit doing its thing while I was aboard working on other projects. During that time there was very little fuel in the tank, so the hope is that the Walbro was able to cycle enough fuel to clean out any remaining sludge. I do think, however, that to get a really good cleaning it's going to be necessary to remove the inspection plate and squirt diesel under high pressure into the tank to stir things up, all the while running the polishing circuit. Perhaps this is something we can get to soon after haul out. For anyone out there interested in a fuel polishing circuit, let me know and for a modest sum I'll install one for you! You do have to live in Michigan, however; I'm not too interested in traveling far.
(8.4.06)
The fuel system continues to function perfectly. The only instance of "failure" was due to operator error. During our sail from Muskegon to Holland ('06) the engine began surging as it had during our first summer aboard ('03). I went below and switched the valve to the secondary circuit. Dad cranked the engine back up and it continued to surge until dying completely. I then realized - all too late - that I had only switched one of two valves on the filtration system, starving the engine of fuel and forcing it to suck air. After bleeding the engine completely, a miserable task at best and painfully miserable over a hot engine, we fired her up and decided that we needed to write up a SOP sheet for some of the more complicated systems aboard. So here it is, my new fuel system schematic and instructions: