Diesel Pre- Filters

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WoodyP

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I have a Kingfisher 30 with tanks in the keels so this is too much of a lift for the fuel pump on the Beta 1005 engine, and this has been overcome with an inline electric fuel pump with a tiny inline petrol filter between the tank and the auxiliary pump.
I have just had a long motor somewhat curtailed by the engine dying. On inspection it was crud in the pre filter before the auxiliary fuel pump.Luckily I had a spare, so I changed the filter and no more problems.
Could anybody suggest a better system, because the small filter is soon blocked. I am thinking of emptying the tank to get rid of any surplus crud, but sods law says it will happen again.
Is there a fuel pump that would raise the fuel about 1m to the engine that would fit on to the engine instead of the pathetic little dinky toy version that is fitted? I would like to do away with having a separate fuel filter and electric supplementary pump, as its just another thing to go wrong.
Thanks in advance, G.
 
Best bet long term- lose the fuel tank in the keel. Fit a Vetus or similar plastic fuel tank in one of your aft lockers, gravity feeding to a duplex primary filter ( two filters combined with change-over valve e.g. Racor type).
Electric fuel pump no longer required, bleeding fuel system easy. Fuel level can be seen through tank sides.
 
The fuel tanks in the twin keels are a good idea in my opinion. They keep the weight down low and having two, at least gives a choice.
K30's don't have cockpit lockers, and I don't really fancy fitting new tanks into scarce space in the rear cabin. Gravity would be best but not an option.
Thanks for the suggestions.
G.
 
Pump -- there is problem in 'sucking' fuel rather than pumping it up. When you suck a partial vacuum is created (or a low pressure) which at a certain height actually causes a genuine vacuum (Torricelli Vacuum). Even before you get to that stage, the low pressure caused by sucking can cause ingress of air. So, provide you can keep the area clean and dry, you are probably better off keeping the lift pump near the tanks. If you are not happy with the present one, have a look at suppliers such as ASAP.

Filter -- You said 'diesel' in the header than talked about 'petrol'. Probably one of the best filters available is the Separ. See http://www.separ.co.uk/ They are the preferred filters for many marine engineers and professional skippers. I've heard of delivery skippers who fit them as a matter of course before doing a delivery. If you are going to all the trouble of fitting a filter you might as well fit the best.
 
The petrol/diesel confusion is that the inline pump and filter were fitted at the time of the re-engine in 2004. Huge expense ended in a bodge from a car parts shop to get fuel up to the engine. The pump and filter is for petrol. Its worked ok'ish up to now but I just wondered if there was a better way to do it.
Thanks,
G.
 
Have you considered a "day tank" ? I guess you will only need a couple of gallons per day, so it might be worth installing a small translucent tank above the engine fuel pump height, and filling it as and when needed. Then you can put clever filters between it and the injectors, as you see fit, and not bother filtering from the keel tank.



Access and checking would be easier for maintenance and tproblem solving.

EDIT
Northup - sorry, I didn't see your post ahead of mine. /forums/images/graemlins/blush.gif
 
I'd still put a filter between the lift pump and the day tank. The best way of keeping your fuel system "clean" is not to let it get dirty in the first place. I'd fit a filter and sight bowl to prevent water getting into the "day" tank. With the deisel in keel tanks, I'd keep a biocide in it, too. If cleaning out sludge is a problem, just think what a sod it'd be to clean out the jelly like deposits of biological contamination.
 
Firstly consult Beta as Macd said, as you must get an electric lift pump that has enough power for the lift but not too much that will blow your injection pump seals. This is from bitter experience, my Leyland engine lift pump packed up so fitted an electic one, 300 pounds later I had a new lift pump and new seals!!!!

I suggest you buy a filter block that elements are easly available in you sailing areas, or carry ample spares a 10gbp element in the UK can be 30gbp in the EU.
 
Woody, there are cheap solutions to this, but only one really reliable and correct one. Keel tanks are great but you do need a mansize filter to take the crud out. The problem then is that you don't say what pump you have but it may well not be man enough to overcome the pressure differential in the filter. Others have suggested a day tank. Thats fine as far as it goes but you need to supply clean filtered fuel to that and have a system to ensure it is not inadvertantly emptied. What I would do is use a Jabsco gear puppy pump (look up Mac engineering..about £120 I think) Then a Racor filter (ASAP supplies... probably about the same cost.)
Fit the gear pump as low as you can as gear pumps are good at pressure not vacuum. The pump comes with a course filter attached and you will need to fit it where it can be easily and periodically cleaned and inspected. You could use this pump to pump directly to a day tank but personally I would fit a 15-20 micron Racor after the pump which will always remove any sludge and dirt to ensure the fuel in the day tank is clean. This does not need to be mounted low down and is best sited where it is easily serviced. The gear puppy pump filter is simply a course "brick stopper" to save wrecking the pump with large lumps, not to supply fuel clean enough for your engine. The day tank will need a fuel gauge or be easily inspected to check contents but it can be arranged so that the outlet is always above the engine ideally. That way the system will be self bleeding. All you need to do then is watch its level and top up with the gear pump when required. If you have a CAV or similar pre filter at the moment, leave it there and route from the new tank to it directly. CAVs are normally a nominal 7-10 micron in reality although sometimes marked 5 and with the system described will work admirably needing very little attention. Hope this is clear and helps. PM me if you need more info.
Mike
 
1) Clean crud out of tank

2) Consider fitting a swtichable system so that if a filter blocks you can switch to a backup pdq. Switchables either from Racor or DIY using a CAV system. Both options (and a diagram for the DIY option) avaliable from asap supplies
 
Boatmike and others, thank you for your suggestions. Another post later says that Beta supplied a booster pump that makes a bit of a clatter but works.
I will take the advice on going to speak to Beta who have been always helpful on other matters.
Cleaning the tank is thankfully not too much of a problem because there is a draining stud at the bottom of each keel.
Larger pre-filters make sense, but it seems to be a balance of pump size and resistance to pumping. I suspect this is just a matter of luck.
Thanks for all the interest.
G. /forums/images/graemlins/smile.gif
 
Having had a K30 I know of the problems with the cast iron keel being used as a fuel tank!
As it is difficult to get general crud out of the system easily, and even if you drain it, you wont get all of it out unless you shot blast which i guess will be almost impossible. The alternative is to live with it.
The RNLI Lifeboats have their filters duplicated side by side, so if one gets blocked, they just switch to the spare, carry on running, and clearing the non operational filter without affecting the engine as it runs. Only needs couple of shut off valves and a short run of pipework, and of course a spare filter of the same type as is being used currently, so spares are compatible
 
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