I was reading all the discussion in July 01 archives on fuel filtering.

My observation for a good filtering installation might be:  (I have a single
671 Turbo)

Dual Racor 1000s with 2 Micron elements
Switchable or use both in parallel
Eliminate the primary on the engine  Good idea or bad?
Use the standard DD 12 micron in the secondary
Convert the secondary to a spin on for ease of changing
Eliminate the fuel cooler, if the fuel is returned directly to large tankage
(boat has 4 tanks, 600 gal total)

If the fuel cooler failed, seawater would be returned to the fuel tanks or
fuel pumped through raw water system?
Is a fuel cooler really necessary with large tankage?

What is the best way to return fuel to 4 tanks evenly?

All 4 tanks externally bottom feed a manifold that supplies the Dual 1000
Racors.
This manifold is level with the 3/4 full mark on all 4 tanks. All valves on
the manifold are always open.
I assume the fuel in all 4 tanks must constantly self level through the
manifold.  Maybe only to the 3/4 full level?

Fuel is returned to the two inner tanks via a T fitting and two return lines
to the top of each tank.
The outer tanks are connected to their inner partner tanks at the top, with
separate vent lines to each tank.

Would an electric priming pump be a good idea in this setup? Or is it really
unnecessary?

I understand Detroit Diesels are easy self priming engines without the need
for cracking fuel lines.

All of that good discussion got me thinking.

Hal Oakes
Traveler, Albin 43
Tenants Harbor, Maine

Hal:

I have a pair of old 6-71 naturals. I use the 2 micron filters with a Racor
1000 for each engine and they hold up surprisingly well. I have kept my old
secondary filters because they don't seem to cause any problems. I have
thought that in case I dislodged some trash servicing the filters or
fooling with the priming system the secondary might pick it up. I don't see
any benefit to removing them.

I also installed a fuel priming system that uses an Walpro pump to bypass
the mechanical fuel pump in case I run out of fuel and have to bleed the
system. Detroits are not easy to start after they become air bound. I only
had to use the priming system once and it worked very quickly. I was told
by the J & T folks that the manual priming pumps are worthless because they
take so long to prime the engine. You could also use the Walpro to
implement a fuel polishing setup and have it serve as a priming pump also.
I would think that on a single that a priming pump would be very desirable.

I don't know a lot about multi tank setups but my experience is that
engines do not draw evenly from multiple tanks and that the conventional
wisdom is to use one tank at a time for supply and return.

The cooling and fuel systems were designed with the fuel cooler and I would
really have to do some serious investigating before I got rid of them.
Perhaps others on this list could give you some advise.

Frank Burrows  79  43' Viking MY  Piney Narrows Marina  Chesapeake Bay