Fuel filter, excessive flow rate problems ?

Roberto

Roberto

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Would there be any problems in using a fuel filter rated for a flow rate decidedly higher than the actual engine flow rate? Say the average sailboat auxiliary engine has a 10-20-30 lph flow rate, what about using a filter with 100 or 200lph flow rate ?

Apart from the cartridge surface, which I suppose the bigger it is the better, a lot of filters function by making fuel twist, swirl, turn, in a sort of centrifugal action, in particular for particles and water separation.

Would the use of a bigger filter impair this function ? Or in other words, is there a necessary *minimum* flow rate for the filter centrifugal action to be correct ?
I looked at the various manufacturers (Parker, Cummins, etc) site but could not find any indication.
 
In short..... No problem in using a filter capable of passing a higher fuel demand, as long as the filter has the correct micron cleaning that you require.

Racor are a very popular filter which will spin the fuel to help remove any contamination but they are fitted to many engines that don't pass enough fuel to achieve the centrifuge effect.

If you want/need a more technical answer one of our resident bowfins will be along soon. :)

Tom.
 
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nigelmercier said:
I wish I knew what my MD22 flow rate was, as I'm still a little concerned about the new filter I bought. Did you find a source of this information?
Click to expand...

Over time I found these general rules of thumb, to be applied in the absence of the engine manufacturer data:
1. 0.7 * HP - liters per hour (effective HP being produced)
2. 0.18 * HP - (from a US filter manufacturer, in US Gallons per hour), I have not made the conversion but obviously it should give the same-ish result as the above :)
3. Fuel hourly consumption * (3.5 to 4)


they should give sensible indications, (at least for my Perkins 4108 they are)

rgds
 
Roberto said:
Over time I found these general rules of thumb, to be applied in the absence of the engine manufacturer data:
1. 0.7 * HP - liters per hour (effective HP being produced)
2. 0.18 * HP - (from a US filter manufacturer, in US Gallons per hour), I have not made the conversion but obviously it should give the same-ish result as the above :)
3. Fuel hourly consumption * (3.5 to 4)


they should give sensible indications, (at least for my Perkins 4108 they are)
Click to expand...

Gosh, my Volvo 2003T must be hugely fuel efficient. Motoring at say 2500rpm it should be developing around 37hp, and it uses about 4 litres an hour - much less than the 26 litres an hour your formula suggests!
 
pvb said:
Gosh, my Volvo 2003T must be hugely fuel efficient. Motoring at say 2500rpm it should be developing around 37hp, and it uses about 4 litres an hour - much less than the 26 litres an hour your formula suggests!
Click to expand...

they are all for fuel flow rate:
with your 37HP, the formula in point 1. gives a fuel flow rate of 25.9 liters per hour; with your 4 liters per hours consumption, the formula 3. gives a fuel flow rate of 16 liters per hour

My Perkins has a bit higher specific consumption and the two results are more similar.

rgds
 
Roberto said:
they are all for fuel flow rate:
Click to expand...

Must have mis-read your formulae.

However, it's worth noting that some engines don't have a return fuel line to the tank, and so for these the fuel flow through the filter is equal to the fuel consumption.
 
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This fuel flow rate must be one of the best kept secrets, no idea why. One always reads "refer to engine manufacturer data" and well, I have quite a number of owner manuals, workshop manuals etc for different makes of engines and no one indicates this data :confused:
 
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