Filters for my CAV assemblies

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pcatterall

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We are happy with our CAV filter assemblies and have mastered the art of changing them ok.
Our primary secondary and fuel polisher assemblies are currently all using Delphi 296 filters which i see are rated at 5 to 7 microns.
This system has worked ok but i wonder if we should have a finer filter in the engine filter ( like2 micron)
Our fuel polisher has done a good job in the past but has had no impact after 4 passes on some particularly black fuel from my tank after winter ( see my recent thread for this saga) so perhaps I should have a finer filter cartridge installed there?
Advice appreciated on this ( we do want to retain the existing cab assemblies though) .
Recommendations on suitable finer filters would be very useful.
Cheers
 
RichardS said:
My engine mounted secondary fuel filter which is part of the standard YM Yanmar is, I believe 2 microns. I use a 10 micron primary filter. I think 2 micron is fairly usual for the final filter.
Click to expand...

Same here, and on my previous boat. Isn't that the point? Putting fuel through an 10 micron filter that has already been through another can't achieve very much.
 
pcatterall said:
We are happy with our CAV filter assemblies and have mastered the art of changing them ok.
Our primary secondary and fuel polisher assemblies are currently all using Delphi 296 filters which i see are rated at 5 to 7 microns.
This system has worked ok but i wonder if we should have a finer filter in the engine filter ( like2 micron)
Our fuel polisher has done a good job in the past but has had no impact after 4 passes on some particularly black fuel from my tank after winter ( see my recent thread for this saga) so perhaps I should have a finer filter cartridge installed there?
Advice appreciated on this ( we do want to retain the existing cab assemblies though) .
Recommendations on suitable finer filters would be very useful.
Cheers
Click to expand...
 
sorry about the dummy post. I fitted a cav/racor adapter so that I could use a 2 micron racor for the final filter. You need to change them regularly. I went int my second season without changing the racor 2 micron and got a blockage in service. Fortunately I had a spare on board and managed to change it quickly. I dont think that it takes much to block them and they are expensive at about £25 each
 
RichardS said:
My engine mounted secondary fuel filter which is part of the standard YM Yanmar is, I believe 2 microns. I use a 10 micron primary filter. I think 2 micron is fairly usual for the final filter.

Richard
Click to expand...


I have just rigorously investigated this.

The percieved wisdom-as I had already worked out-is that mechanicaly governed diesel engines require a 30 micron pre filter and a 10 micron secondary. The OE manufacturers engine mounted filter for mechanicaly governed engines is invariably 10 microns.

Common rail diesels-the more up to date computer controled type- require 10 micron primary filters and 2 micron secondary filters.

The VERY old fashioned CAV type are effective water separators and pretty crude particle filters.

I am impressed with the Racor copies of their 900 series available off ebay for under 50 quid. They have the distict advantage of being top loaders-little mess when changing and the bowl can be topped up from a small container before fitting the top, so eliminating a lot of the bleeding.

IMHO the old CAV type are the work of the devil and are messy and tricky to change-especially if mounted in a tricky to get to place, as many are in my direct experience.

I am just installing a Racor knock off as a secondary on our boats main engine, plus a couple of collar lock modern types for the generator which should be installed in the next couple of weeks. The collar lock type are not so convienient to change as the Racor type but can be pre filled with fuel and inserted without spilling much, so assisting the bleeding process.

I am using them as they came as a special deal from a JCB agent for 50 quid the pair.

Both engines use electric pumps, the main engine for bleeding only, the genset for fueling, so bleeding is quick and easy.

For santelmo-I pay about 12 quid each for 30 and 10 micron genuine Racor elements
 
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santelmo said:
sorry about the dummy post. I fitted a cav/racor adapter so that I could use a 2 micron racor for the final filter. You need to change them regularly. I went int my second season without changing the racor 2 micron and got a blockage in service. Fortunately I had a spare on board and managed to change it quickly. I dont think that it takes much to block them and they are expensive at about £25 each
Click to expand...

I pay half that for 30 and 10 micron elements.
 
santelmo said:
The one I pay £25 for is the 3216 like this https://www.asap-supplies.com/racor-s3216s-spin-on-element
its the spin on type that fits the cav adaptor. Yes the drop in type that fits the 500 housing is much cheaper I have one of those as my primary filter.
Click to expand...

I see-I wrongly assumed you were using the Racor 900 series elements as I do.

Good reason to change to the pattern Racor 900 series from ebay-less than the cost of two of your spin ons.

What engine do you have? Is it a common rail type?

If it is not, you might find a 10 micron filter is less likely to block.

Check out the Inline filters website-very good prices and a huge range.
 
Bloke in our club has just made a polishing rig using 3 filters in a line.
First a cheap filter with a cleanable sintered element.
Second a CAV
Third a filter from a Citroen HDi

The third filter gets him 5 micron elements for about £3 apparently?
It's quite hard to find the micron spec of typical car filters.
 
rotrax said:
I see-I wrongly assumed you were using the Racor 900 series elements as I do.

Good reason to change to the pattern Racor 900 series from ebay-less than the cost of two of your spin ons.

What engine do you have? Is it a common rail type?

If it is not, you might find a 10 micron filter is less likely to block.

Check out the Inline filters website-very good prices and a huge range.
Click to expand...
my engine
is a ford 2712 dorset made in dagenham in the 70s so not common rail. I now regret the spin on adaptor and am thinking of going back to the cav on grounds of cost.
 
santelmo said:
my engine
is a ford 2712 dorset made in dagenham in the 70s so not common rail. I now regret the spin on adaptor and am thinking of going back to the cav on grounds of cost.
Click to expand...


In that case the 2 micron filters are not required.

Check the " Inline Filters " website and see if you can find some 10 micron spin on filters at a better unit price.

I will be surprised if you cant. I entered the Yanmar oil filter number in their search engine and found two alternatives to the really expensive Yanmar OE filter at a quarter of the price.
 
Just had an interesting respond from the Marine 16 guys to my my black diesel question. They believe that my 5 to 7 micron filters will not touch the black aspheltine deposits in my fuel and state that these particles can be submitting! I will post their full response when I am back in UK .
I have been relying on repeated passes through the polisher as this has worked in the past however it would be interesting to see if i can locate a 2 micron filter to fit the cab assembly just to see if it would restore this contaminated diesel ( i have just thrown away 15 gallons of it !!)
 
AIUI, many of the filter cartridges used for water filtration in 10 inch housings like this:
http://www.ebay.co.uk/itm/10-Water-...53f57bc&pid=100009&rk=1&rkt=1&sd=112044760258
can be used with diesel. Filter cartridges are 3 or 4 quid and available in '1 micron'.
OTOH, Aspheltine is a lot denser than diesel and ought to sink in the fullness of time. (?)
It's also questionable whether it will be doing any harm?
 
pcatterall said:
Just had an interesting respond from the Marine 16 guys to my my black diesel question. They believe that my 5 to 7 micron filters will not touch the black aspheltine deposits in my fuel and state that these particles can be submitting! I will post their full response when I am back in UK .
I have been relying on repeated passes through the polisher as this has worked in the past however it would be interesting to see if i can locate a 2 micron filter to fit the cab assembly just to see if it would restore this contaminated diesel ( i have just thrown away 15 gallons of it !!)
Click to expand...

Just about a year ago I had to dispose of 700 litres!

And there was a labour charge and an enviromental charge adding another 200 quid to the bill!

Saving grace was that Neilsons Shipyard in Gloucester Docks got me 410 litres at about 56p per litre.
 
lw395 said:
AIUI, many of the filter cartridges used for water filtration in 10 inch housings like this:
http://www.ebay.co.uk/itm/10-Water-...53f57bc&pid=100009&rk=1&rkt=1&sd=112044760258
can be used with diesel. Filter cartridges are 3 or 4 quid and available in '1 micron'.
OTOH, Aspheltine is a lot denser than diesel and ought to sink in the fullness of time. (?)
It's also questionable whether it will be doing any harm?
Click to expand...

That is the type of filter I use in my polishing rig, one take off from the drain and another tapping into the top of the tank using a 12v fuel transfer pump, best done under way rolling on and off thethrottle so the tank gets a shake up while pumping, I got loads of crud out.
 
A few years ago I had a problem with my fuel, and did considerable research before making my own fuel polishing rig for around £100, which has been a complete success and everything has been fine since.

There are some common misnomers about fuel filtration.
One is that a 5 micron or 2 micron filter will get everything out - it won't. As has been witmnessed in the threads above.
The big problem is moisture, and entrained moisture rather than "free liquid".
To get that out you need a coalescing filter, of the type used in modern common rail diesels.
The filter medium in the Fleetguard filter (1221, IIRC) I used gets about 90% of the mositure out, as well as holding about 6 times its own weight in crud before it blocks.

After filtering through this, the fuel went from a very dark almost brown colour to a light pink.
It was very obvious it was doing its job properly.

So forget the micron rating, it's how much moisture the filter removes that is the important bit.
If you remove the moisture, you remove the habitat for the diesel bug to live in, so you won't get any bug problems. Your standard CAV and engine filters will then be perfectly satisfactory to get on with their day job of getting the particles out. But on their own they won't remove moisture.

My suggestion would be for anyone to do some more research and fit moisture absorbing filters.
Get in touch with Fleetguard Technical Services to get details on the best filter & filter head for your application. Filters are cheaper than Racor and available at most truck & commercial vehicle factors & filter outlets.
 
As a finance person I am not qualified to speak about engineering matters. However I was controller of the company which owned the Lucas Rotodiesel (CAV) plant in France.

There were some comments made by engineers there that I remember: (FWIW)

Never let a diesel engine run out of fuel because the injectors are lubricated by the fuel passing through them.
The engineering tolerances are 1/10 of a micron. That would imply using the finest filters possible.
The parts for an injector are so finely engineered that they are manufactured in sets and are not interchangeable.
 
Quite correct, but in a marine envioment using really fine filters can cause lack of power and engine failure.

As I stated in a previous post the percieved wisdom is that 10 micron filters are normal spec for mechanicaly governed pumps-IE old generation-and 2 micron for common rail modern type.

It must be remembered that many contaminants in diesel fuel are not hard sand or grit but softer glutinous oily substances that require removal. Many of these will not damage or wear the hard material of the pumps.

Roto-diesel made fine equipment. IIRC they also had a plant in Spain.
 
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