Dual Fuel Filters

[Chalker]

I'm planning to install two fuel filters with taps to switch between them in case of blockage, as part of the fit-out for a long-term cruise.

CAV housings are common and the filters available cheaply just about everywhere, but they are a pain in the neck to change and seal.

Screw-on filter are convenient and easy to change, but more expensive and commonly do not have a water trap.

Racor drop-in filters are beautiful but the prices are certainly not, for the housings or the filters.

Any suggestions?

 

[captainboo]

Filters

I used these:

http://www.ssldieselparts.co.uk/filter-assembly-sfa10-p-715.html

Although they do not have a clear water trap section there is an equivalent area at the bottom of the filter with a drain. They are spin on and relatively cheap. If you do need a dedicated water trap you could always fit a separate one.

 

[Baggy]

Why not go the whole hog and fit one of these.. fuel polishing system

http://www.asap-supplies.com/marine/fuel-systems

I am in the process of installing the system on my boat..

 

[pcatterall]

I thought I would just use 2 CAVs. Yes more fiddly but less of an issue if you can change over.

 

[Deleted member 36384]

.... CAV housings are common and the filters available cheaply just about everywhere, but they are a pain in the neck to change and seal. .... Screw-on filter are convenient and easy to change, ..... Any suggestions?

Here is the link to the CAV Products at ASAP supplies. Plenty of low cost CAV options including spin on filters and separate water traps. Hope this helps.

 

[Ex-SolentBoy]

Here's what we have

 

[pvb]

I'm planning to install two fuel filters with taps to switch between them in case of blockage, as part of the fit-out for a long-term cruise.

CAV housings are common and the filters available cheaply just about everywhere, but they are a pain in the neck to change and seal.

I've got this system, with CAV filters. As long as there's reasonable access, it's not a difficult or messy job to change a CAV filter, and I've never found sealing to be a problem (although you do need to understand that there are two different diameters of the large sealing ring). On my installation, with a keel tank, I can't bleed a new filter with the engine running.

I fitted a vacuum gauge, which indicates as the filter being used progressively clogs up. It's a good way of ensuring that you only change filters when actually necessary.

 

[Gordonmc]

I found the cost of Racor filters eye watering, but found a copy of the Racor 500 which is now fitted and working. £80 against £140.
I like the ability to change the filter elements without the faff of locating O rings properly, just unscrew the top and drop in.
The copies use Racor replacement elements.
Sold on fleabay and, I am sure, other outlets.

 

[Trundlebug]

I stuck to CAV filters with my changeover system.

Although I agree they're a bit fiddly, they're not fiddly enough to justify a filter price of £80 (or even £140) compared to £2, especially if you fit an alloy bowl rather than a glass one, thereby removing one seal, and reducing changeover and sealing problems and also complying with BSS (even if you do disagree with it).

Once a year I use Fleetguard filters fitted to my fuel polishing system to ensure the fuel is free from bug and major problems, so there's no need for expensive Racor or equivalent as permanent fit. The CAV filter now lasts a season anyway.

The Fleetguard filters (spin-on) are as good as or better than Racor but only around £15-20 each, with the filter head being about the same. They also absorb 90% of any entrained moisture in the fuel, thereby preventing bug problems.

 

[KellysEye]

Be very careful with cheap fuel filters they don't have a pressure relief valve, which you can see in a Racor.

 

[pvb]

Be very careful with cheap fuel filters they don't have a pressure relief valve, which you can see in a Racor.

Is a pressure relief valve desirable in a primary fuel filter??

 

[Trundlebug]

Be very careful with cheap fuel filters they don't have a pressure relief valve, which you can see in a Racor.

A pressure relief valve is the last thing I would want.

If it's blocked, I don't want unfiltered fuel being let through.
Other than that, the fuel is under suction from the lift pump anyway, so no pressure other than tank head height.

Can't see the point

 

[pvb]

A pressure relief valve is the last thing I would want.

That was my thought too.

 

[RivalRedwing]

Be very careful with cheap fuel filters they don't have a pressure relief valve, which you can see in a Racor.

oil filter not fuel filter methinks?

 

[Canopy Locked]

This is a pic of my set up - works well; easy to change filters and, using the O/B primer bulb it's dead easy to re-prime the new filter.

 

[Chalker]

Thanks everyone for your suggestions.

I think that I'll go with a CAV type head with 496A spin-on filters; more than the 296 elements but as they are longer I assume that they'll last longer.

I'll try and fit a pressure gauge across the system to monitor filter state, any suggestions on pressure range?

Ex-Solent Boy - what a work of art! I've found L port T valves on ASAP and Aquafax, where did you get yours from?

 

[pvb]

I'll try and fit a pressure gauge across the system to monitor filter state, any suggestions on pressure range?

You need a vacuum gauge, fitted with a T-joint into the line between the filters and the engine's lift pump. Racor do one, which you can buy here - this is the one I've fitted on my boat. The gauge has coloured bands indicating when filters need changing.

 

[RivalRedwing]

Thanks everyone for your suggestions.

I think that I'll go with a CAV type head with 496A spin-on filters; more than the 296 elements but as they are longer I assume that they'll last longer.

Just make sure you use pukka Delphi or Fleetguard filters + I think that you will find that Land Rover Defenders used (still use?) them) so a genuine Land Rover part will also be a safe bet

 

[pvb]

Just make sure you use pukka Delphi or Fleetguard filters

Why? Wouldn't a Fram, Purolator, Bosch, Inline, etc, etc, work just as well?

 

[RivalRedwing]

I was tryingt to steer the op away from the likes of cros*and - a pump & injector specialist I know has a very dim (anglo-saxon) view of pattern filters. To my mind he shouldn't have as he believes they are the root cause of much of his business.