New Engine Fuel Return

[gavin400]

I am installing a new engine which has a fuel return
The existing engine (Volvo MD11C) does not return the fuel to the tank, so I need to run a return line to the tank - my question is:
Does this return need to be a certain distance from the supply or can they be next to each other?

Many thanks

 

[scottie]

Ideally they should be as separate as practical to stop any air or hot fuel being recirculated

 

[Refueler]

All I can do is show the arrangement on my tank ...

The pipe to the right next to the rag / tissue is the fuel feed to engine .... the pipe next to the sender is the return from engine. The distance between is about 25cms ..

 

[pvb]

Perhaps the best solution is to have a flexible tube on the return, inside the tank, so that returning fuel is introduced at the bottom of the tank, away from the pick-up pipe. This also prevents aeration of the fuel. This is the system used by Volvo Penta on their fuel tank plate. This photo shows the VP pick-up pipe (with mesh filter) and the plastic return pipe.

 

[Refueler]

Neat ..

 

[jamie N]

My tank has no return 'hole/penetrator', as the original engine was petrol. I have tee'ed the return line into the fuel feed line, just below the fuel tank and have had no ill effects from it over the years and several hundred hours of running.

 

[Refueler]

I think if there was no entry into tank itself - to save cutting and threading a junction - I might look at using the tank filling line to plumb into.

 

[gavin400]

I'm thinking of a new tank, so wondering if there is a best practice re siting the supply and return pipes

 

[pvb]

I'm thinking of a new tank, so wondering if there is a best practice re siting the supply and return pipes

See post 4 perhaps...

 

[PetiteFleur]

I fitted a new plastic fuel tank which had all the required fittings for fuel in; fuel return and for a gauge. Mine was a Plastimo but also made by others such as TekTanks, Osculato etc. Rectangular in several sizes, mine was the 81 litre. Cheaper than a custom made tank and of course won't go rusty!. (But don't get the mechanical fuel gauge as is unreadable after a couple of years)

 

[William_H]

I think the answer to the OP is just do what is easiest by way of plumbing. Yes it should go back in to the tank but possibly OK just teed into pick up line. Help[ed a freind do this with a tank that had a fitting above the filler point on the tank. (below hose to deck filler) it was easy to remove this fitting and drill and tap a hole in the side of it for the return line. I don't imagine spacing inside the tank is really important. it is not like over heating of fuel and vapourisation is likely in diesel. ol'will

 

[ean_p]

I seem to remember that Perkins used to fit the return to the top of the engine mounted fuel filter.......or have I just dreamed that?