Tuesday, Jan 22, 2013 at 22:31
RA & Rich
There are a number of products which attempt to remove water from fuel.
Here is my
views on the subject.
A 1HZ motor for instance using 12L/100km uses the 12litres in approx 1 hour. That is a fuel usage of 1.2 L /10 min. and returns a minute amount back to tank. So an overall fuel flow rate of 12L + a bit /hr from the tank.
A similar sized CRD engine using 12L/100km uses the same amount of fuel for the engine but returns approx approx 25 to 30 L back to tank for cooling reasons as the dump off from the rail and the low pressure fuel control regulator. So this engine has a flow rate through it's fuel filter of at least 35 to 40 litres /hr. BIG DIFFERENCE increase.
This means the fuel flow force through the filter is also increased.
If the fuel filter has a larger/area flow rating then the flow through every sq cm is less than a small filter.
A steel tank cools the fuel, a plastic tank vehicle HAS to have a cooler.
Added filters or WW in engine bay are in temps around 70 to 80degrees so the fuel is being heated before it hits the engine. Sort of negates the intended design requirement somewhat.
My Isuzu has a system flow rate of 35 litres /hour so I use a filter which has 114litre/hr flow rate and 100psi pressure rating although the system pressure is 6 to 7 psi regulated.
I selected after some research, a Donaldson P902976 Low Flow Fuel filter kit.
This easily handles the flow requirements of a 3litre engine and far exceeds the max OE filter flow of around 70L/h.
The P 550588 filters have a bowl at the bottom which you can see and an easy drain valve.
The filter is around 10 microns and has the feature of a claimed 99% fine particle removal so catches 99% of everything 10 microns and bigger.
It also has a claimed 95% efficiency at removing water from the fuel because of the filter medium used. The lower the flow through this filter means the more water emulsified in the fuel it can remove in a given time. This isn't the water which drops to the bottom anyway, it is the water swirling in the fuel flow.
That's why my idea of two filters plumbed in parallel for a 4.5 V8 will mean a far greater filtering capacity and slooow (is good) fuel flow through the filters. This means less flow pressure ie need to get through in a hurry, so the filter/s has the maximum time to do it's work.
These are throw away filters so you need to carry spares (2 supplied with kit) but the two allows for greater bowl water entrapment and a vastly bigger filter area for the above advantages to work.
If out on the track and a filter blocks you can just change one and only bleed it and continue until full servicing can be achieved.
This all leaves the OE filter idling along and not stressed and working as it should and also as a back up with it's sensor system untouched.
Other filter manufacturers have other options and research will determine if they suit what you want. The price of
mine was one factor considered and I have no proof if it is the best or not, but the alternative of not having something reasonably effective is not an option for me.
I don't have a WW or a Mr Funnel but they are ok for what they do, for a CRD engine it doesn't mean much for me but everything must help.
I hope this makes sense for you and I in no way are recommending any product over another, it is just what I have selected. Racor too long.and 3x price.
You can contact Donaldson, I did and found them very helpful.
I'm interested in your thoughts.
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