Ski in NC
Technical Guru
It's good to have a secondary. Changing elements on a racor can let a "burp" of crud flow downstream. Also, as racor elements age, they can loosen on the central post and let crud through. I'd put a secondary back on.
In my opinion the filters on the engine are unnecessary with a modern filter like the Racors. The primary should be all that is neccesary.
It's good to have a secondary. Changing elements on a racor can let a "burp" of crud flow downstream. Also, as racor elements age, they can loosen on the central post and let crud through. I'd put a secondary back on.
>your post is dead on. The problem is that many of these pleasure boats do not have a low spot sump, or for that matter any easy way to do a low point drain. Many tanks have no clean out panels, and no access to the tops. So the normal practices for maintaining fuel and tanks is difficult. <
You get what you pay for , many trawler style boats were price built so do not have a proper fuel tank, just a metal box with fuel in it.
Sadly even when replacing these iron units , most dont purchase fuel tanks , just another box to hold fuel.
Raycore filter elements are cheap by the box , so they stay popular.
This question usually generates a lot of opinions. Diesel as it leaves the refinery is filtered to 30 microns and on the Lehman, that will work just fine. If your tankage is greater than what you typically run through in a month or so of usage, a 30 micron that will return the fuel to refinery spec as primary (first in line) is fine, especially if your OEM filters are 10 microns. With three filters, the sequence would usually be 30, then 10, then 2 micron. A pre tier II engine like yours isn't going to benefit from filtering to 2 microns, so suggesting putting a 2 micron filter as a primary is nutty, IMO, since it will be forever clogging if your tanks are large. My engine is also pre tier II, and for what it is worth we polish at 30 microns, transfer fuel to the day tank at 10 microns where it passes through 2 micron filters before hitting the OEM filters that are whatever they are.Excuse my ignorance, but previously on my sailboat I only had one fuel filter to change.....
Currently on our boat, we have a Lehman 120 with three filters leading from the tanks in the following order:
FRAM CCS1136 5 micron (seems to be original)
Racor 500FG with 2 micron (looks to be added at some point)
On Engine Dual CAV @ 10 micron (the stock Lehman filters)
This appears to be what is installed in the boat currently, based on the documentation I have.
I seem to have no choice as to the micron rating for the FRAM or on engine CAV units, but the Racor I can choose 2, 10 or 30. Is the 2 micron what should be installed? If so, does that mean my on engine filters aren't doing a darn thing?
Any advice? Thanks in advance.
This question usually generates a lot of opinions. Diesel as it leaves the refinery is filtered to 30 microns and on the Lehman, that will work just fine. If your tankage is greater than what you typically run through in a month or so of usage, a 30 micron that will return the fuel to refinery spec as primary (first in line) is fine, especially if your OEM filters are 10 microns. With three filters, the sequence would usually be 30, then 10, then 2 micron. A pre tier II engine like yours isn't going to benefit from filtering to 2 microns, so suggesting putting a 2 micron filter as a primary is nutty, IMO, since it will be forever clogging if your tanks are large. My engine is also pre tier II, and for what it is worth we polish at 30 microns, transfer fuel to the day tank at 10 microns where it passes through 2 micron filters before hitting the OEM filters that are whatever they are.
And, methinks that if you have a high gpm polishing system of say, > 2 gpm, and you polish the fuel when the tanks are so low you can barely keep from sucking air then you never will have to clean your tanks. I think there is enough real world experience to validate that. I polish when underway with relatively full tanks for drill, but I can't convince myself that I am removing all precipitants from the fuel. Likewise, when I polish on a nearly empty tank in a seaway, I can't convince myself that I am doing anything BUT removing all the crud. And let's suppose I am not removing ALL the crud, although I don't see how I am not. Nevertheless, I am simulating exactly the situation where crudded tanks ever cause a problem and that is when the boat starts tossing and loose stuff starts clogging the filters. So that potential, IMO, is eliminated even if I miss a bit here and there.
Modern diesels, especially those that are Tier II, III an IV are normally set up this way. Ditto large truck diesels burning +200 gph sometimes eliminating the first stage if the the fuel trucks are filtering fuel as dispensed. A 3 stage setup will deal with badly fouled boat tanks so long as the fuel can exit the tank.
As posted in loving detail by Flywright a year or so ago, there are good ways to have your tanks cleaned.
on many small vessels, multiple drains or a center deep one may not be accessible no matter how great of an idea they are.
If it is too fine to get caught in a 2 micron filter, it is too fine to do harm to any engine.Fine stuff found in the bottom of filters is common as NO media filter can remove the really fine stuff.