MD6A: return fuel line needs fuel pump?

[Vega1447]

A previous owner moved fuel tank to port cockpit locker (presumably to
make the electric fuel lift pump unnecessary).

He also left the new (Vetus) tank without a vent/breather pipe - an
omission I fixed today.

(Not sure *how* the tank/fuel system "breathed" without a vent - I
suspect bad pipe connections were involved somehow!)

(I fitted a s/s spigot to the top of tank and connected up the old
breather pipe to the tank so the tank now "breaths" through the original
breather fitting on the outside of the port coaming.)

The fuel return line (from engine back to tank) runs all the way from
the engine return line spigot *aft* parallel to the drive shaft and back
forward to the tank in port cockpit locker - a long way around.

I have shortened the run as there was a bad union between the original
fuel return pipe and a larger diameter pipe used to connect it to the
spigot on the top of the tank.

I started to wonder: there is about a metre rise from the engine return
line spigot up to the fuel return spigot on the top of the tank.

Is this a problem; is there too much back pressure in the line?

If so maybe a small aux tank in engine space with a squeeze bulb as a
poor man's lift pump?

Thanks for any comments.

John V1447 Breakaway

 

[j.hunter9999]

John,

Its hard to know specific to your situation, but I moved the tank to the port locker last year. It sounds like your configuration is similar to mine, with about a 1 meter rise to the top of the tank. I have not had any problems with the fuel system since the move. I ran the motor for about 2 hours last season.

Hope that helps.

Jack,
Bella - V2620

 

[Vega1447]

Thanks Jack.

I'll see what happens when I start the engine. She's on hardstanding for
another few weeks.

John

j.hunter9999 wrote:

 

[bobnlesafloat]

Spring Fever's tank has been located in the lazarette locker for all of the nine years we've owned her; diesel feed is by gravity and the returning fuel is presumeably just 'pushed' back to the tank; I've never really thought about it before, but we've certainly never had any problems.

Bob Carlisle

 

[pjacobs55]

I'm no Diesel mechanic, but I think the fuel going up the return line is under pressure already.

My setup is the same: gravity feed and pressure return, and has worked fine for over 25 years.

I'm using the old gas tank (copper) in the starboard locker. It has a ball velve shut off at the forward end (fuel outlet coming out of the tank top) and a breather at the aft end. My return line goes into a 'T' fitting in the breather hose, just above the tank.

Peter
#1331 'Sin Tacha'