Wayne.B wrote:

On 28 Mar 2007 10:43:38 -0700, wrote:


Mount them above and chances are you will become a Detroit fuel rack
expert in no time;0)


Solved that problem.

After an "interesting filter change incident" I had my diesel guy
install electric priming pumps on each engine. They can be valved in
and turned on in about 5 seconds. Total cost was less than $300 for
two engines. The reliability improvement is priceless.

If the fuel tanks are mounted below engine level which is typical on
many sportfish and motor yachts, it is just about impossible to mount
the Racors below tank level. Even if you can there is still an issue
with changing the engine mounted filters. Priming pumps, that's the
way to go.

Hi Wayne,

I only have a single engine (Yanmar) and I'm
considering installing an electric boost pump with
twin y'ed filters, and a day tank. I haven't got
it completely thought through yet, but I think I
should be able to set up the system to

1) Auto fill the day tank with filtered fuel from
the main.

2) Polish the fuel in the main by running it
through the filters and back into the main

3) Polish the fuel in the day tank by running it
through the filters and back into the day tank
(don't know why I'd want to do this...)

4) Prime the engine by pressurizing the fuel line
into the injector pump. (I'd still have to crack
a bleed valve up by at least one injector).

5) Allow a filter change while the engine is running.

6) Brew coffee and tea, and make donuts, etc. ;-)

I'd like to hear more about your fuel system
setup. It sounds interesting.

Don W.

On Wed, 28 Mar 2007 14:50:08 -0500, Don W
wrote:

I'd like to hear more about your fuel system
setup. It sounds interesting.

It's very straight forward.

I have no day tank.

Each engine has the usual engine mounted filters.

Ahead of each engine is an array of 2 Racors (total of 4), each with a
ball valve on the intake and outlet. This allows either filter to be
selected or isolated, or both filters could be in paralell.

The output side of the Racors has a vacuum guage to monitor the
condition of the filter. In the event of a higher than normal vacuum
reading I open the valves for the backup filter, and close off the
valves for the old filter. The old filter is now isolated and can be
changed on the fly.

In between the Racor's and the engine mounted filter is an electric
fuel pump which is normally valved off and unpowered. If I need to
prime the engine mounted filters, the electric pump is valved in and
turned on. This forces fuel into the engine filters and though the
injection loop to the fuel return. This could theoretically be used
for polishing but I don't because I have a separate polishing loop
with its own pump that just draws fuel through the Racors and sends it
back to the tank.

On Mar 28, 3:39 pm, Wayne.B wrote:
On Wed, 28 Mar 2007 14:50:08 -0500, Don W

wrote:
I'd like to hear more about your fuel system
setup. It sounds interesting.

It's very straight forward.

I have no day tank.

Each engine has the usual engine mounted filters.

Ahead of each engine is an array of 2 Racors (total of 4), each with a
ball valve on the intake and outlet. This allows either filter to be
selected or isolated, or both filters could be in paralell.

The output side of the Racors has a vacuum guage to monitor the
condition of the filter. In the event of a higher than normal vacuum
reading I open the valves for the backup filter, and close off the
valves for the old filter. The old filter is now isolated and can be
changed on the fly.

In between the Racor's and the engine mounted filter is an electric
fuel pump which is normally valved off and unpowered. If I need to
prime the engine mounted filters, the electric pump is valved in and
turned on. This forces fuel into the engine filters and though the
injection loop to the fuel return. This could theoretically be used
for polishing but I don't because I have a separate polishing loop
with its own pump that just draws fuel through the Racors and sends it
back to the tank.

So... you just bleed the air off at the filter housing as you "prime
it"?

Joe

On 28 Mar 2007 20:14:27 -0700, wrote:

So... you just bleed the air off at the filter housing as you "prime
it"?

The DD injection system is self bleeding as long as it's receiving
pressurized fuel. Usually a minute or so with the priming pump is all
that's necessary.

On Mar 29, 5:42 am, Wayne.B wrote:
On 28 Mar 2007 20:14:27 -0700, wrote:

So... you just bleed the air off at the filter housing as you "prime
it"?

The DD injection system is self bleeding as long as it's receiving
pressurized fuel. Usually a minute or so with the priming pump is all
that's necessary.

Thats OK as long as your engine is not to hot, and it does not take
to long to get all the air thru the system. DD injectors use fuel flow
to keep them cool.

Joe

On 29 Mar 2007 06:35:08 -0700, wrote:

The DD injection system is self bleeding as long as it's receiving
pressurized fuel. Usually a minute or so with the priming pump is all
that's necessary.

Thats OK as long as your engine is not to hot, and it does not take
to long to get all the air thru the system. DD injectors use fuel flow
to keep them cool.

You don't run the engine when priming so heat is not an issue. Most
times if I'm using the priming pump it's because I changed one of the
engine mounted filters which I always do cold anyway.

On Mar 29, 9:47 am, Wayne.B wrote:
On 29 Mar 2007 06:35:08 -0700, wrote:

The DD injection system is self bleeding as long as it's receiving
pressurized fuel. Usually a minute or so with the priming pump is all
that's necessary.

Thats OK as long as your engine is not to hot, and it does not take
to long to get all the air thru the system. DD injectors use fuel flow
to keep them cool.

You don't run the engine when priming so heat is not an issue. Most
times if I'm using the priming pump it's because I changed one of the
engine mounted filters which I always do cold anyway.

What if both filters clog offshore?
You going dead in the water in a storm while swapping filters?

I thought that was the purpose of having two filter housing and piping
them to shift from housing to housing.

Joe

Wayne.B wrote:

I'd like to hear more about your fuel system
setup. It sounds interesting.

It's very straight forward.

I have no day tank.

Each engine has the usual engine mounted filters.

Ahead of each engine is an array of 2 Racors (total of 4), each with a
ball valve on the intake and outlet. This allows either filter to be
selected or isolated, or both filters could be in paralell.

The output side of the Racors has a vacuum guage to monitor the
condition of the filter. In the event of a higher than normal vacuum
reading I open the valves for the backup filter, and close off the
valves for the old filter. The old filter is now isolated and can be
changed on the fly.

In between the Racor's and the engine mounted filter is an electric
fuel pump which is normally valved off and unpowered. If I need to
prime the engine mounted filters, the electric pump is valved in and
turned on. This forces fuel into the engine filters and though the
injection loop to the fuel return. This could theoretically be used
for polishing but I don't because I have a separate polishing loop
with its own pump that just draws fuel through the Racors and sends it
back to the tank.

This sound a lot like what I'm thinking about,
except for the lack of a day tank. Sounds like
you thought it through pretty well when you
designed it.

Don W.