Need for spin-on fuel filter with double Racor 500s?

[Tin Kicker]

The Ericson 32-3 with the M25 engine has a 10 micron spin-on filter tucked away in the bottom back corner. (Notice the nice cracks in the coolant hose in lower right. Nearly all hoses on the boat are 35 years old so in process of replacement.)

The boat already has a Racor 500 filter/water separator and I happen to have a second one. Does anybody see an issue with simply removing the spin-on so the second Racor does the same job? The fuel lines would then go:

Tank
Fuel shut off valve
Racor #1 at 30 micron (currently 10) which is in suction as Racor recommends to trap water
Facet electric cube pump
Am considering adding a 2-way valve here with one side to the tank for fuel polishing.
Racor #2 at either 10 (as is) or 2 micron which would be under pressure
Injector pump inlet

It'd be a lot easier to inspect and change the filters this way, plus less of the inevitable clean-up under the spin-on.

 

[Christian Williams]

You can just put a 2-micron on the engine and forget about it. A 10-micron on the primary filter is common practice.

The only reason I can see for a second Racor 500 is so you can change filters while the engine is running. That's mighty handy, and requires them plumbed for "either-or." If you have glop in the tank requiring frequent filter changes it's a solution.

Fuel polishing for our small tanks I don't understand. The engine "polishes" the fuel while it runs. If I had ten gallons of old, suspect fuel in the tank I'd just recycle it and buy new.

 

[debonAir]

Do you have room for two? I'm trying to find a spot to mount a single racor in the engine room replacing an inline secondary spin-on filter. Where do people put them? Also, some of my fuel runs are copper tubing now and I am considering replacing them with rubber because the copper seams perhaps fragile for some reason. Any ideas on that? Where so you get custom length fuel hoses with the proper fittings?

 

[Alan Gomes]

The Ericson 32-3 with the M25 engine has a 10 micron spin-on filter tucked away in the bottom back corner. (Notice the nice cracks in the coolant hose in lower right. Nearly all hoses on the boat are 35 years old so in process of replacement.)

The boat already has a Racor 500 filter/water separator and I happen to have a second one. Does anybody see an issue with simply removing the spin-on so the second Racor does the same job? The fuel lines would then go:

Tank
Fuel shut off valve
Racor #1 at 30 micron (currently 10) which is in suction as Racor recommends to trap water
Facet electric cube pump
Am considering adding a 2-way valve here with one side to the tank for fuel polishing.
Racor #2 at either 10 (as is) or 2 micron which would be under pressure
Injector pump inlet

It'd be a lot easier to inspect and change the filters this way, plus less of the inevitable clean-up under the spin-on.

When I get around to it I plan to post a blog (with pictures) about the recent changes I made to the fuel system on my 1GM. But there are certain points of commonality with what you are suggesting.

I removed the on-engine fuel filter from the 1GM (a known problem for that engine) and rely entirely on my Racor 500, which is a very high capacity filter. I love that filter. It is super easy to change without making a mess. Plus, the filter media are cheap. I use 10 microns. I also have the optional drain petcock so I can empty the housing before doing a filter change. I could actually change this thing in a seaway if I ever had to.

I have it plumbed via a 2-way valve. Position #1 goes straight to the high pressure injector pump and Position #2 goes to the injector return line. While I could use Position #2 for fuel polishing, the main advantage is that I can prime the filter with the flick of the switch that energizes the fuel pump, mounted in the engine compartment.

There's no need for the extra on-engine filter if you've got the Racor doing its job. That filter should never get dirty anyway if it's downstream of the Racor. It's just one more failure point you've eliminated, not to mention a needless expense.

I wouldn't go with a 2 micron filter as it is hard on the fuel pump.

 

[Loren Beach]

Do you have room for two? I'm trying to find a spot to mount a single racor in the engine room replacing an inline secondary spin-on filter. Where do people put them? Also, some of my fuel runs are copper tubing now and I am considering replacing them with rubber because the copper seams perhaps fragile for some reason. Any ideas on that? Where so you get custom length fuel hoses with the proper fittings?

Note from my blog that I scouted out a different location for a new Racor near, but no longer in, our engine compartment. Every boat different in possibilities, in that respect.
I found that my '88 diesel had been plumbed with copper supply and reinforced hose for the return. Modern reinforced hose being rated for diesel, I replaced both of those over a decade ago. Deck fill hose, also!
I have replaced the vent hose too. Modern fuel-rated "hose" is a lot more than just 'rubber'. There are layers of material for strength as well as stopping permeation. As for length, these hoses are all cut to fit in place and secured with ss hose clamps onto barbed fittings.

Plus, be sure that everywhere you fasten a hose up, you use a "cushion clamp" ... i.e. rubber padding around the metal clamp. No chafe worry.