Racor Filter Emptied before starting

[Mikel Arechabaleta]

I am installing in my 38 Chris Craft two 430 hp Recón Cummins 6CTA engines with two racor FG1000 filters.  Before starting the engines, I fill the fuel filters and they are emptied shortly before starting the engines and I don’t understand why?  I wonder: should the filter retain the fuel?  Does the engine have a check valve?  Everything installed is new and I don’t know where I can have the error and if this is normal?  Can you help me with some ideas?  I can thank you very much

Topic

[pwrobert]

I Stand Corrected

A quick Google search does indeed say the ball acts as a backflow preventer.

The Seaboard spinon filters don’t have backflow preventers and I asked Tony about the use of backflow preventers a couple of months ago and he does  not recommended them.

So we are back to why Both drain their fuel.  I feel it is from an air leak.  Likely after the Racor or in the Lid to the Racor itself.  Check the edge of the filter body where the square cut oring seals for any roughness often from chipped paint.  Replace both the squarecut oring and the smaller round one to the lid and cover both sides of the orings with sticky grease before placement.

 

1 user thanked author for this post.

David Amble

[David Amble]

I beg to differ re the purpose of the aluminium ball valve.  Please read the attached article from Passage Maker Magazine.

[pwrobert]

Not Check valve

The check valve mentioned above is not of the type you are asking about. This ball is a floating ball that floats up in the case your bowl totally fills with water. <br />it is not an anti-siphon valve. <br /><br />

how many fuel tanks does your boat have. We’re these the original tanks the came with the gas powered engines. If so – been there done that. The factory gas fuel pickup tube has a hole drilled in it near the top to act as an anti siphon valve of sorts. Gas engines don’t care if a little air is in the fuel. But diesels do and this can lead to suction breakage. Also if run for a while the continuous little air introduced will eventually empty the Racor as well. Happen to me with my first repower back in the ‘80s. Since then built new fiberglass tanks to replace the original steel ones from the factory. 

[Rob Schepis]

Are the Racor assemblies both new too?  And they are both doing the exact same thing?

[David Amble]

Leaking check valve / seal

The racor filters have an internal check valve ball and seal so I suspect these need replacing.  Racor Check valve kit RK15010B.

[pwrobert]

Photos Of Racor Setup

Three 1005 gallon tanks, a manifold sustem for Supply and Returns and an electric pump hooked up off the remaining Racor to transfer fuel between tanks or prime the engines or filters.  Sole reason I left the Racor in place is that its elements are cheap and easy to change when I use it as a fuel polisher or to transfer fuel between tanks.

I installed twin 6BTA 370 and get good performaqnce you should really do well also.

[pwrobert]

Another 38 Chris

On my Chris Commander 38 I ran it with Twin Detroit 8.2l for 25 years. They had Racor 1000 as well. When I repowered in 2019 I replaced one set with seaboards Double Double spin on filters. But left the Racor on the port with the addition of one of Seaboards bull filter spin-one before the remaining unit. <br /><br />

as far as the loss of fuel I suspect it has something to do with the height of the filter mounting relative to your tank(s).  <br />What is the distance in height between typical fuel level and the Racor inlet. <br /><br />

Also are there any significant loops or dips in the fuel lines between the tank(s) and Racor. If so that may create a backflow. <br /><br />

yours seems really fast though. I added a third center tank down low in the bilge between the engines and it will Slowly suck back if the Supply valve is left open. But since adding the spin-on ahead of the Racor that doesn’t seems to still be an issue. The two side tanks which are at engine level and at the same level as the Fuel filters never have an issue. Actually, if the side tanks are over 1/2 full they will self prime the filters by gravity with the valves open. Not so with the center tank. My priming pump is required. <br /><br />

I suspect you have an air leak at or after the filters and or some of the other items listed. 

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