Logo
FULL SITE MENU

How many fuel filters are really needed?

J

joeld98

Member
My factory Crusader installation had three filter points for each engine. The Main Racor Filters in a manifold between the two tanks (3 Total Filters; 1 for each engine & 1 for Genny), One mounted near the starter and the filter on the Rochester Carb itself.

The new Edelbrock carbs did not have a filter. I built up stainless fuel lines with an inline billet filter between the fuel pump and the carb.

Is the Canister style filter before the fuel pump necessary? If it is absolutely necessary, are there any restrictions on where it's placed between the main filter and the fuel pump?
 
I deleted my canisters as the builder put racors in before the pumps, too. Mine were a real pain to get to move when unscrewing. No problems here. I'd delete yours, too.
 
Funny, I just discovered those canister flters today. One had been bypassed and the otehr had no element (I discovered this while in the process of destroying the canister to get it open) I know have both engines bypassing the canister filter ;)
 
Realistically, all you need is a coarse water/ crud filter to protect the pump, and a fine filter after the pump to protect the carb. About 25 to 30 micron for the trash remover and 10 micron for the carb protector filter. This is a long-established and proven system.

Jeff
 
The Racor filters are great and are a more true water seperating filter..... You should have no issues with these being your Primaries!
However, I would question the use of a filter installed in the pressure side of your system (from pump to carb) whether billet style and/or metal fuel line or not. Is this USCG approved?

.
 
Last edited:
I checked on the "USCG Approved" questions. The only filter requirements are:
Fuel filters and strainers may not use the attached fuel lines for their primary means of support. Many fuel filters and strainers have brackets designed to provide support. If brackets are not provided as part of the fuel filter or strainer, clips, straps or other means must be employed to support the fuel filter or strainer independent of its connected fuel lines.
So as I have it installed it would not meet these requirements. I'm going to build up a support bracket for the inline filter to comply.
 
Joeld98, you mentioned reading the "requirements", and that is all dandy!

What I suggested was to learn whether or not your parituclar In-Line filter..... (the one IN THE PRESSURIZED FUEL LINE from pump to carburetor)....., is legal.
 
The only concern I'd have is to use good hose clamps on the ends, if A1 hose is used. The wire clamps are illegal. Since you've made up the stainless lines, the filter attachment points should NOT be an issue. With the filter made from billet stock, that shouldn't be an issue either. When in doubt, check the CFR text, directly.
 
HOLY COW , So I went to the CFR on fuel piping and zoned right out. Dyslexic???Maybe. So in east coast english, what does it really mean.... Is is safe to say that the fuel line can be that A1 stuff or does it need to be stainless or steel with annealed ends that were square cut, etc etc.....

I was planning to replace the fuel lines and filter housings one rotten weekend this summer but now I am a bit hesitant. I would'nt want to have gotten this far and then foul up the fuel lines. Currently 1 line for each engine goes from one tank with three shut offs ( 2 engines and a generator) to a canister (each engine) then to the pump then to the racor(for each engine) then to the carb...

There is metal line in there somewhere but I currently forget where to where. If I absolutely knew it was stock and approved, I would simply replace it with the same configuration..BUT in 4 years of working on this boat I have found that NOTHING was ever done properly
 
Last edited:
knuckle47 said:
............
Currently 1 line for each engine goes from one tank with three shut offs ( 2 engines and a generator) to a canister (each engine) then to the pump then to the racor (for each engine) then to the carb...

There is metal line in there somewhere but I currently forget where to where. If I absolutely knew it was stock and approved, I would simply replace it with the same configuration..BUT in 4 years of working on this boat I have found that NOTHING was ever done properly
Click to expand...
The RACOR is NOT approved for use in the location as described above (red text).
While the hose that meets the A1 spec is legal here, any filter apparatus AFTER the fuel pump becomes the issue! (this is where the fuel would be under mild pressure.... 4, 5, up to 6 psi or so)

IMO, your RACOR units should be your "Primary" filters, and installed somewhere between your fuel tank shut-off valves and your engine fuel pumps..... and in the suction side ONLY of the system.

Go with the Micron size of your choice, but keep the RACORs as your Primary Filters...... You really do not need any other filter, IMO.
It doesn't get much better in this category of filtration systems. :)

The filters in the carburetor inlet are great..... keep up on routine replacement.

NOTE: All too often I see the little band clamps (hose clamps) being used on fuel lines whereby the ID is NOT correct for the hose OD.
The "band" itself is correct, but the hard/stiff area directly under the "worm drive" screw is often of an incorrect diameter for the hose OD.
As you can imagine, this can cause an issue later on, if not sooner!

So when selecting a clamp, make sure that THIS area ID/Radius is correct for your fuel line OD!


.
 
Bracing hard-piped fuel filters located AFTER the fuel pump with a bracket is a good idea, for I know of at least two cases where such filters (not bracketed) rpped open from vibration, fortunately without destroying the man's boat. (He was damn lucky!)

It may be illegal, but I use A1 hoses and clamps to connect my in-line metal filters (located after the fuel pump). They not only absorb vibration, preventing the filters from cracking and leaking, they make filter changing a snap. Some inspector might someday boo-hoo it, but I'll keep it that way until forced to change it!

Jeff
 
fastjeff said:
It may be illegal, but I use A1 hoses and clamps to connect my in-line metal filters (located after the fuel pump)
Click to expand...
Jeff, what's your back up plan should you have a leak here? :eek:
I can see it now..... bilge blowers bringing in fresh air...... engine fuel pumps pumping away...... Yikes, Jeff!
 
1. My connections don't leak! And I check them (and other things) regularly to be sure. A zillion cars have come from the factory with fuel filter connections such as this, and for decades, without a problem. Furthermore, I've seen lots of flared fittings that DO leak! How about you?

2. I have a fume detector down there and never leave the slip without it running.

Jeff

PS: I appreciate your concern, but I've seen TWO hard piped filters on a boat identical to mine that ruptured their cases and were leaking gas. That boat now has a setup like mine--I installed it--and hasn't had a problem since.
 
There is nothing wrong with the racor being on the pressure side of the pump as long as the pump doesn't exceed the pressure rating on the can. Mercruisers were set up that way for decades....that said, parker will tell you the efficiency is impacted when used downstream of the pump but that's a different discussion.

Nothing illegal with Jeff's setup though the "A1" markings may not be obvious on the short coupler hoses. It's using those one piece wire spring clamps that is the prohibited action with the inline filters.
 
"how many filters are needed" ? My vote is one per carb. engine. A coarse, water seperating type. I don't like any filter in the pressure side, nor do I see any substantial reason to have one there. Pressurizing a fuel filter, while it can be done with safety, poses an unnecessary risk.
 
I just don't want to hear of, read about or see, this! :D
I want all of us to be safe!

explosion.jpg
 
Back
Top