Will I need to bleed..

[petery]

the diesel supply to my engine if I cut the fuel line and insert a tee piece to take a fuel feed for an Eberspacher heater - ie how much air in the fuel line could cause a problem. I'm new to diesels and have a 2 cyl 20hp Lister Petter engine.

Any hints would be welcome.

 

[andy_wilson]

Yes

The manual will normally suggest taking the supply from an independant tapping of the tank. Any connections in the engine supply are an invitation for air leaks in the suction side and are to be avoided.

However, if you do go by this route, any amount of air will need to be purged, which is a routine you should be able to complete rapidly in a bucking cabin whilst boat is being blown onto a lee shore.

Consider it first practice session!

 

[dickhicks]

Yes, you will need to bleed it - it will probably start and run for a little while untill the air gaets to the injectors and then it will stop! Unless you have the modern diesels which can sel bleed.
Probably easier to bleed as soon as you have fitted your tee piece. There is probably a hand operated fuel pump, release the bleed screw on the top of the engine mounted fuel filter and hand pump until diesel comes out without air bubbles. Shut off the bleed screw and repeat for the bleed screw on top of the fuel pump - if you have one, otherwise bleed each injector in turn by cracking the union nut on top and tightening when air free fuel flows. Then start the engine - if it doesn't start immediatly repeat the above.
Have loads of rags handy to catch the spilt fuel.

 

[petery]

I reckon it's an RYA diesel course for me asap.

 

[vyv_cox]

Eberspacher fuel

I did the same as you are intending - fitted the T-piece downstream of the primary filter. This ensures clean fuel to the very small jets in the Eberspacher. Neither the engine nor the heater have suffered in the slightest from this location.

You may well not need to bleed, as the amount of air you will introduce is very small and can probably be coped with by the engine. It won't do any harm to bleed from the secondary filter, though. Let gravity do the work, bleed until the air comes through and then run the engine.

 

[hlb]

Or you could use the quick, no frills option. Undo a couple of injector pipes. Hang on you only have two. So maybe just one. Then wiz engine round till it starts or maybe on only one cylinder, tries to. Then tighten nut. Much easier, though you will spray a bit of diesel about so better to stick a rag over it.
Saves all the fanying around and much quicker.

Haydn

 

[rex]

Re: Eberspacher fuel

I know you shouldn't but if you are going to take the feed from downstream of the primary filter you may be able to use a spare outlet on the filter instead of cutting the pipe.

 

[petery]

Re: Eberspacher fuel

That sounds interesting...what are the risks?

 

[alanporter]

Rather than tap into your engine fuel line, have you room for a day tank ? Your stove is not likely to use lots of diesel in a day. I use a two gallon outboard motor fuel tank filled with diesel and connected directly to the stove. This doesn't risk compromising your engine supply, but of course it depends on whether you have room for it. Good luck.

Alan Porter

 

[petery]

Had considered having a separate tank - but hadn't thought of using an outboard tank. Thanks for the suggestion.

 

[LadyInBed]

Re: spare outlet on the filter

Thats a good idea.
Re: Bleeding
As you will be doing this work with the engine off (I assume
You will only need to bleed the low pressure side. Thats up to the input to the Injector pump using the mechanical lift (hand primer) pump.
(The high pressure side has to be done by using the starter motor or hand cranker)

A tip:
Cut a small plastic milk container to fit under the union that you are bleeding to and tie it there with string or wire. This should catch the fuel that bleeds out and stop it going into the bilge. Also you will see how much fuel you have pumped through.

 

[vyv_cox]

Re: Eberspacher fuel

It's a good idea, but I've never seen a primary filter with more than one outlet. What types are available?

 

[dickh]

Re: Eberspacher fuel

From memory my CAV primary filter/water separator has twin outlets, one with a blanking plug and the other for the feed to the engine. But if you go this route check it out!

dickh
I'd rather be sailing...

 

[chas]

Re: Eberspacher fuel

It has (or at least mine has) but I am not sure if you would get filtered or unfiltered fuel out of it.

 

[Celena]

Re: Eberspacher fuel

The feed to my Eberspacher works this way. It's filtered. (I've an isolating valve just after it) To me, it's the obvious way of connecting...

 

[JerryHawkins]

I used the stand pipe

I used the stand-pipe supplied in my Eberspacher kit. There was some suggestion that if I wanted the heater running at the same time as the engine, one or other may be starved of fuel slightly and performance affected.

Cheers,

Jerry