Racor Fuel and Water separator, E10 gasoline, and other ramblings
Here is the Racor I installed on my project boat recently. These come with a metal or plastic bottom, and it’s very important to use the METAL bottom like this one on an inboard boat.
E10 (10% ethanol) gasoline, used on the Great Lakes and East Coast, can eat through the plastic. There is a report of this in the current edition of Motor Boating Magazine.
Many of our Commanders came with the big Groco fuel filters, and they do a great job. However, this type of Racor, also serves as a water separator, and that’s what the drain plug in the bottom of the unit is for. It won’t take large quantities of water out, but it will take some.
I like the easily replaceable element.
Racor - 320R-RAC-02
1 RK20180 Mounting Head
2 20707 O-Ring / Gasket Pack: all units
3 S3228UL Element (10 micron)
4 RK30473-02 Metal Bowl and NPT Plug, white powder coating
5 918-N6 Steel Port Plug, 38/
22237 Installation Instructions
Another thing I heard recently about E10, or any alcohol based fuel these days. It will cause your fuel tanks to lose internal varnish flakes. It will clean your tanks! Now the bad news, it will clog your filter and your fuel line pick up tube.
The following is from Power & Motoryacht, which I have edited for older (Commander) watercraft.
E10 is a blend of unleaded gasoline and ethanol, no more than ten percent by volume of the latter. Ethanol—basically grain alcohol—replaces MTBE as an oxygenate to reduce carbon monoxide emissions. It's better for the environment and healthier for folks than MTBE, a known carcinogen.
Any gasoline engine manufactured in the past 15 years will run on E10. If your engine is older, keep an eye out for leaks in fuel lines and connectors, because ethanol and other alcohols will degrade rubber. Thus 15-year-old rubber fuel hoses might be damaged by ethanol—but if your fuel lines are that old, they're overdue for replacement anyway.
Ethanol is a solvent that will dissolve varnish, sludge, and other crud inside the tank and fuel lines—basically it will clean them. The fuel filters on many boats let the tiny contaminants pass through to the engine, where they can clog injectors and accelerate wear. On our older boats, this means all the junk on the walls of the tanks will be loosened and it will fall to the bottom of the tank. This means more frequent filter changes during the cleaning cycle, and a potential for clogging at the fuel pick-up tube inside the tank, itself. If you are in an area that sells E10 marine fuel, it may be a good idea to replace your conventional fuel filter with a 10-micron water separator designed for ethanol. Most experts predict the filters will clog frequently when you first switch to E10, so carry spare elements. Once all the debris has been strained out, the elements should live a normal life span.
Ethanol can draw moisture out of the air through the fuel-tank vent, enough to cause trouble if left in the tank too long. Ethanol will separate from the gasoline on its own over two or three months, even if no water is present, again putting the engine at risk if the pure juice gets into the fuel lines. When running on E10, it's wise to patronize marinas with lots of business, so the gasoline in their tanks is always fresh.
There are also issues with water contamination. Ethanol can absorb ten times as much water as MTBE can and carry it through the engine to be burned away. However, if the concentration exceeds the fuel's saturation point (about 0.5 percent by volume), the process reverses: The water pulls the ethanol out of the E10. Engineers call this phase separation. The ethanol-water mix sinks under the pure gasoline, which is now of slightly lower octane (ethanol boosts the octane of E10 about three points higher than the gasoline alone). Low octane could cause the engine to run poorly, burn more gasoline, and emit more pollutants. If enough of the ethanol-water mix collects under the gasoline, it can be drawn into the engine. We all know engines don't run so well on water, but pure ethanol can also be damaging.
These problems aren't difficult to solve. First, use your boat frequently, so there's always fresh gasoline in the tanks. When storing her, leave the tanks empty, and refill with fresh gasoline when you re-commission. (Check with your boatyard for its requirements on this.) Finally, and maybe most important, always use a non-alcohol-based additive to preserve the fuel, like Star brite's Startron. The company claims it will stabilize E10 gasoline for at least one year. Gold Eagle's Sta-Bil is another good choice.