LaBomba182 wrote:

Subject: Fuel transfer/polishing pump
From: Jere Lull


You don't want too fine a filter on the suction side. On Yanmars (and
others), the lift pump can fail sooner due to the restriction.



My point is if you use a large surface area small micron filter and change it
regularly, you should never see high suction pressures.


If you do both, it's better, of course. We balance cost in there
someplace, of course. I figure a new 30-micron filter will have one
third (or 1/9th?) the resistance, switching up to a 900 would only
(about) halve it. When there's a bit of dirt, though, the 30 micron
filter will clog less while still protecting the lift pump.

The idea
is to do the cleaning in stages: 30 micron before the lift pump, 10
micron just before the high pressure pump. That said, we used 10 micron
Racor elements for 8-9 seasons and 1000 hours with no significant ill
effects except when we got a shot of algae.



8-9 years without changing the element! Your perpetuating a stereo type Jere.
:-)


You're right, that wasn't entirely clear. We change the filters each
spring as cheap insurance. I haven't noticed any discoloration in the
primary filter or bowl except when I brushed the Racor during the algae
incident, and that could well have been my mishandling.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Subject: Fuel transfer/polishing pump
From:

On 29 Nov 2003 20:48:01 GMT, (LaBomba182) wrote:

Subject: Fuel transfer/polishing pump
From: (Steven Shelikoff)

Not much difference between diesel and oil.

Perhaps, but there is a world of difference between the tolerances of a
fuel
injector pump and an oil pump.

True. But that's a red herring since it's not usually the oil pump that
wears out due to dirty lubricating oil.

Not quite. A 350 Chevy engine will run for a long time, years maybe, with dirty
oil.
A diesel injection pump and/or injectors with dirty fuel will not.

Capt. Bill

Subject: Fuel transfer/polishing pump
From:

On 29 Nov 2003 20:48:01 GMT, (LaBomba182) wrote:

Subject: Fuel transfer/polishing pump
From: (Steven Shelikoff)

Not much difference between diesel and oil.

Perhaps, but there is a world of difference between the tolerances of a
fuel
injector pump and an oil pump.

True. But that's a red herring since it's not usually the oil pump that
wears out due to dirty lubricating oil.

Not quite. A 350 Chevy engine will run for a long time, years maybe, with dirty
oil.
A diesel injection pump and/or injectors with dirty fuel will not.

Capt. Bill

Subject: Fuel transfer/polishing pump
From: "Doug Dotson"

The memo from Yanmar (via Mack Boring) didn't make any distinction
on type of filter. Just the porosity on the element. Perhaps it was a CYA
move to specify anything smaller than 30 uM.


If that's the case, then you have to do what they say.
At least until the warranty runs out. :-)

Capt. Bill

Subject: Fuel transfer/polishing pump
From: "Doug Dotson"

The memo from Yanmar (via Mack Boring) didn't make any distinction
on type of filter. Just the porosity on the element. Perhaps it was a CYA
move to specify anything smaller than 30 uM.


If that's the case, then you have to do what they say.
At least until the warranty runs out. :-)

Capt. Bill

Subject: Fuel transfer/polishing pump
From: Jere Lull

I figure a new 30-micron filter will have one
third (or 1/9th?) the resistance, switching up to a 900 would only
(about) halve it.

I would guess much less than that. Based on the surface area of a 900.

You're right, that wasn't entirely clear. We change the filters each
spring as cheap insurance.


Got it. :-)

Capt. Bill

Subject: Fuel transfer/polishing pump
From: Jere Lull

I figure a new 30-micron filter will have one
third (or 1/9th?) the resistance, switching up to a 900 would only
(about) halve it.

I would guess much less than that. Based on the surface area of a 900.

You're right, that wasn't entirely clear. We change the filters each
spring as cheap insurance.


Got it. :-)

Capt. Bill

Subject: Fuel transfer/polishing pump
From: "Doug Dotson"

Huh? Bubbling up fuel? It helps it as much as drawing the fuel from
one baffled area into the engine. Better to draw it into a polishing
system for a while.

But unless the fuel is shaken up real well most of the crud is still at the
bottom of each baffled area in a nice little mound.

Capt. Bill

Subject: Fuel transfer/polishing pump
From: "Doug Dotson"

Huh? Bubbling up fuel? It helps it as much as drawing the fuel from
one baffled area into the engine. Better to draw it into a polishing
system for a while.

But unless the fuel is shaken up real well most of the crud is still at the
bottom of each baffled area in a nice little mound.

Capt. Bill

Subject: Fuel transfer/polishing pump
From: "Len Krauss"

No offense -- but have you?

Yes, many times.

They're are not solid top to bottom as you seem
to suggest.

Never suggested that.
I assumed it was understood that there would have to be a way for the fuel to
travel from one baffled area to the next.


The plate bottoms, in particular, usually have tunnels.


More like notches.

Capt. Bill