Friday, July 22, 2011

Fuel system is complete

The fuel delivery end of the job is complete with the main engine and generator connected to the day tank. It was kind of anti climatic as I screwed down the last hose clamp, and realized I have no more work to do on the fuel system.

I installed check valves after the manifold. I was worried that one engine might try to pull fuel out of the other engine. I spoke with a few diesel mechanics, and all agreed that check valves would not hurt and were probably needed.

The line supplying the main engine after the manifold is 3/8" coast guard rated rubber fuel line. The return line from the main engine is the same rubber line only in 1/4". I had JIC fittings crimped on the fuel supply line for the main engine and used push on connectors for the returns.

I routed the supply and return for the main engine through the engine bed. I used a hole saw to create the bores, and then used 1 1/2" rubber grommets to pretty up the bore and prevent any chaffing of the lines. I used the same detail on the generator supply and return

The line feeding the generator is 5/16 coast guard rubber fuel line,and the return line is the same 1/4". I had to bush the return line up from 3/16 @ the generator return port. The fuel supply line on the generator is a push on connector as the generator manufacturer uses the Banjo style fitting at the fuel inlet.

The 1/2" electric priming pump looks as if it is not going to work. I got the pump to prime with a 5' piece of brake line and a bucket of fuel. However, in the real world, the pump will not pick up the fuel once I have it installed and it has to lift through the fuel filter, pipe network, valves and four feet of lift. I have to re visit the electric priming pump and get a model pump that can handle the lift and friction loss I'm placing upon it.

All the return fuel lines enter the tank at return manifold.

While both engines could be fired now, I'm really not ready as I want to get the exhaust systems completed for both engines. I'm working on the generator wet exhaust first, then I'll attack the dry exhaust for the main engine. Since I'm going to be doing the generator wet exhaust, I need to finalize the wiring in the lazzerette and finish sheathing that room. Once the lazzerete is sheathed, I can make the wet exhaust connections and check another item off the list. I'm at the point now that I want to be able to scratch these jobs off of the list and not have to re visit them. This order of work is logical as I won't be able to start the steering system until the lazzerete is completed, and the bulky wet exhaust gear is installed.

Since I am now working on the wet exhaust system for the generator, I might as well install the sea chest as the generator will be needing it's cooling water. I even hung a spare gasket for the flange connector, and the wrench for the strainer housing. Once the wet exhaust is completed, I can fire the generator. The numbers you see in the last picture is how I labeled the fuel tanks. #2 is the 200 gallon day tank, and #1 is one of the 500 gallon storage tanks.


  1. Good job, From my short experience in boating (8 years is enough?) It's one of the fields in your baby to be dealt with extreme care, because it has huge potential for breaking down off shore.

  2. I agree 100 percent. My years of owning multiple diesel engines has taught me 98% of all problems are fuel related.

  3. After many years working on engines, statistics show that cooling is the biggest problem causer, followed by fuel, followed by lube oil (neglect).