A new fuel filtering system for Aurora
On Aurora there is a huge 90 HP Ford Lehman engine that by all accounts is one of the most reliable engine of that size ever built. Reliable, that is, as long as it gets fed clean fuel and all the normal maintenance chores are performed on time.
Here is apparently the OEM primary fuel filter for the 90 HP motor:
It is a little frightening to think of this single filter dealing with dirty fuel just purchased at some out of the way Caribbean fuel dock and then stirred up by motoring into the trade winds. It would obviously clog up in short order and there would be no 'hot' standby.
Enter a dual fuel filtering system with the following requirements:
- There must be two huge filter / water separators
- You must be able to switch between the two on the fly
- Either filter must be able to draw from either tank
- The engine return must be able to feed either tank
- There must be an electric pump for the following reasons:
- to act as a backup lift pump,
- To transfer from one tank to another
- to polish, albeit slowly, fuel through the filters
- There must be an emergency shut off
- There must be a vacuum gauge visible from the cabin
All these requirements meant many valves and interconnection plumbing, which the pix will testify to.
There are three 2-way valves:
- Tank selector
- Filter selector
- Return tank selector
The right most valve will get a small wire attached to it from where it will run up through the cabin sole to a small handle that will serve as the emergency shutoff.
I had to put in-line valves in the filter out circuit to isolate a filter completely so as to change it under way.
Click on a picture to see a larger image.
Since the pictures were taken, I labeled all the valves, filters, etc. and drew some instructions on the cross bean just above the system so that even a yard mechanic could understand. Or me when panicking...
Here is a diagram of the system:
