Fuel filter improvements

[billyfish]

I am moving my primary fuel filter to the locker side of the engine bay bulkhead so I can change it without putting my back out, it will add about 6" of pipe between it and the engine it will also raise it about 6" I don't think that will cause a problem, maybe a bit longer to bleed it but hopefully won't affect the flow, unless you know otherwise. I'm also thinking of adding a filter on the return to polish the fuel . But is that just silly

 

[sailoppopotamus]

What would the filter on the return really accomplish? If it's rated to the same microns as the primary filter, the fuel will just pass through it. If not, and it is a finer filter, why not just use the finer filter as your primary? Either way, the fuel returned has probably been filtered twice, once through the primary and once through the finer secondary filter mounted closer to the engine.

If you have the space and appetite for two filters, you could mount them in parallel with a switch, so that in the event that one gets clogged you can switch to the 'spare' immediately. But again, I'm not sure that would be better than just getting a filter twice the size to begin with. I imagine that it would take more abuse before clogging, but when it does you won't have an emergency backup.

 

[Momac]

I'm also thinking of adding a filter on the return to polish the fuel . But is that just silly

I wonder why no one else thought of that .
I do know of someone who accidentally left the return feed valves closed . It not only caused a large fuel leak but required a new fuel pump. So extra resistance to the return flow may not be a good idea.

I also know someone with the above suggested extra filter and switchover valve fitted, and he has used it.

 

[superheat6k]

Polishing requires the filter to agglomerate droplets of entrained water and obviously any debris particles travelling with the fuel. Swirling the fuel flow also helps because the water and debris is normally heavier than the fuel so move outwards on a centrifugal separator. the Racor filter uses both effects to separate water and debris particles, before the cartridge element agglomerates any water droplets and then sifts out any remaining debris particles.

So by the time the full has reached the spill return pipe it has been thoroughly filtered already and indeed squeezed through some very narrow gaps.

This literally smashes up any water droplets into particles too small to be agglomerated.

Therefore for polishing purposes the best place is on the direct line out from the tank and before the first pump.

 

[Sandy]

I'm also thinking of adding a filter on the return to polish the fuel . But is that just silly

Yes.

 

[Plum]

I am moving my primary fuel filter to the locker side of the engine bay bulkhead so I can change it without putting my back out, it will add about 6" of pipe between it and the engine it will also raise it about 6" I don't think that will cause a problem, maybe a bit longer to bleed it but hopefully won't affect the flow, unless you know otherwise. I'm also thinking of adding a filter on the return to polish the fuel . But is that just silly

Depoends on the design of the filter. Some will allow fuel to run back into the tank if higher but assuming you have a shutoff valve at the tank you can stop that. Don't see the point of addind a third filter after it has already passed through two.

Www.solocoastalsailing.co.uk

 

[RivalRedwing]

better & easier to put a vacuum gauge on the primary filter to monitor its health. Fuel polishing (and draining any water from the tank) is better done in other ways.

 

[billyfish]

Ok I get it the only reason I thought of this is because I got a Chinese spin on filter to replace my primary filter when I got to replace it it seams easier to move it to where I can get to it leaving me with a spare. I can make up a polishing set with it as I have a pump. Next question is my primary a good one , see photo, seams ok to me and now I can get to it , i think i will stick with it as the Racor are hundreds of pounds and I'm a poor old pensioner.

 

[Stemar]

If you're going to do all that, go one stage better and fit twin spin-on filters in parallel with taps so you can switch between them in seconds and change a blocked filter with the engine running. I did this on Jissel and got a pair of filters from a car breaker. It was a few years ago, but the whole job cost me change from £50 - probably £100 now

A rather fraught entrance into Portsmouth Harbour under sail was what persuaded me to do it, but a side benefit was that, having a spare filter, I no longer changed them as a matter of routine, only when they became sufficiently corroded to be of concern, maybe every ten years. And, of course, reverse Sod's law, since a blocked filter was no longer more than a minor inconvenience, I never had another one.