Narrow Boat Albert: Diesel Drip Pot

Diesel Drip Pot

The Ruston & Hornsby 2YWM in Albert has a Mico (Bosch India) direct injection system that utilises a pair of jerk pumps driven from the crankshaft. The two pumps are controlled by a rack attached to the governor. As part of the system minute amounts of fuel can seep past the rack mechanism. This leakage is normal and is emitted from a port at the base of the injector. When Phil Lizuis was working on the engine a short time ago he pointed out that some similar engines have a drip pot fitted to collect this fuel. The drips are few and far between but they are occasionally noticed. After I recently carried out an oil change I decided that although the amount was very small, allowing this fuel to collect in the drip tray below the engine was not really acceptable so I set about designing a collection system to fit onto our engine.

Fuel drip line from direct injection pump

The two ports on the injector pumps are 5/16 UNF - or so I found out after some investigation. It isn't easy establishing internal thread sizes on a engine with mixed Imperial and Metric thread sizes and the R & H parts manual I have wasn't very specific. I decided to connect the injectors to a drip pot using standard 1/8 inch flexible fuel pipe that is commonly used on a variety of diesel engines. This should have been quite simple via standard brass adapters but the fuel filters on our 2YWM were too close to one of the pumps and so I had to resort to making up a pair of special short adapters. The drip pot I sourced by adapting a glass-bowled fuel pre-filter. I removed its internals, adapted its porting to take two fuel inlet pipes and then drilled an air-vent into the top. The drip pot is bolted low down on the side of the engine casing. I will have to wait and see just how much fuel makes it into the pot.