Twin Fuel Tank Configuration

Sealizard · Posted: Sat Nov 02, 2013 11:39 pm Post subject: Twin Fuel Tank Configuration

Been searching the site for information on twin fuel tank configuration and have not found an answer to our concern.

We have twin tanks for our 40HP engines. They are setup so that you run both engines off one tank, then switch to the other tank as needed.

We are considering re-configuring the system so that each engine runs on its own tank. In addition, we would retain the capability for each engine to switch to the other tank.

Any thoughts about this strategy before we make the big leap?

ghone · Posted: Sun Nov 03, 2013 12:05 am Post subject:

Hi there. First thing comes to mind is there any problem with running your tank as is? Seems most of us would be plumbed this way and it makes it easy to track what tank you're on. Two tanks out to one switch to one racor then off to two engines. Run for an hour or two then switch tanks. You'll be building a manifold, bigger more complex boats do this... but we're little and simple. Adding complexity to fuel delivery isn't high on my boat project list. Others may have ideas but I like it simple and bullet proof. Fuel issues and electrics being the two trouble makers aboard. George

hardee · Posted: Sun Nov 03, 2013 1:55 am Post subject:

For my twin 40's I have a single tank for each engine. No switching. Separate fills and separate racor filters, and no combining. Works for me. Easy to keep track of which engine runs more if I am running single.

Harvey
SleepyC Moon

BRAZO · Posted: Sun Nov 03, 2013 6:43 am Post subject:

rogerbum · Posted: Sun Nov 03, 2013 1:35 pm Post subject:

My tomcat was initially configured to have each engine burn from it's own tank. While this has some advantages, a serious disadvantage is that with such as system, if one engine fails, the fuel associated with that engine is not available to the other. In such a situation, your expected range is cut down considerably. Also, most of us with twins can't get on plane with a single engine. So, if we lose one engine, we're left with the choice of running at hull speed to get decent fuel economy or running faster and taking a big hit in fuel economy since we can't get over the bow wake (further reducing range). This is especially a concern for long offshore runs or situations which require long runs between fueling stations.

Since I frequently fish 40-70 miles offshore, if I lose an engine, I don't want to come back at 6kts to conserve fuel and extend my range. So I had my fuel system re-plumbed with a manifold and cross over valve

thataway · Posted: Sun Nov 03, 2013 2:25 pm Post subject:

I have always thought a cross over is a good idea with twin tanks and two engines. The boats I have had with twins have been inboard diesels, and I usually ran on one tank for both engines, but always had the capability of both running on two tanks (one for each engine) or transfering fuel from one tank to the other.

Sealizard · Posted: Mon Nov 11, 2013 1:52 am Post subject: Twin Fuel Tank Configuration

Thanks for the thoughtful replies. We're debating the pros and cons. Appreciate the input.

jerry97230 · Posted: Mon Nov 11, 2013 11:29 am Post subject:

My boat has a seperate tank for each engine and I like it this way. If I get fuel contamination problems, it should only effect one engine.
As far as being able to use the fuel in the other tank in a single operation, I can just unclip the fuel lines from the engines and clip the other one onto the engine that is running.
Jerry C Nile

Sunbeam · Posted: Mon Nov 11, 2013 11:39 am Post subject:

Hunkydory · Posted: Mon Nov 11, 2013 12:01 pm Post subject: