Fuel Pick-up Fitting

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When I decided to build a fuel polishing system, I wanted it to be simple. It needed to be easy to build, inexpensive considering other options, modularized, and I didn’t want more valves, switches, and piping than a nuclear power plant. Additionally, I wanted it to be totally independent of all other fuel system pumps and plumbing. I think I have accomplished this to an end.

My M-III is one of those having dual 118-gallon tanks located down the port and starboard side. I already had that CVA piece of junk on the rear bulkhead, followed by a spin-on Racor 210 for the Generator on the one branch and a 500FG Racor on the main branch to the engine. Add to that all the shut off, return valves and pick-ups and it got ridiculous quickly.

I sat one entire Sunday afternoon contemplating how I could install a polishing system and meet all the above objectives. I sketched countless drawings and even a few times thought I had it, and then it became clear after about five, may be six beers what needed to be done. I had to do away with the traditional copper rats’ nest and make it simple. In fact, it could be done in such a way as to make it portable or at least easily removable.

The front top inboard edge of each fuel tank had a plug, and that plug was a ¾" pipe thread. At first I could not get the plug removed. The compound that was applied to the threads made it very difficult. I found a rag soaked in lacquer thinner wrapped around the plug for a few moments softened the compound to the point it was easily removed. So I thought, why not a single pick-up and return in one fitting.

The trick in this thing is that you take a standard compression fitting and if you look inside it, it has a ridge to stop the pipe from being inserted further than necessary. What you do is bore the thing out with a 3/8" bit so that your pick-up tube will pass all the way through the compression fitting and through the tee to the bottom of the tank. Slide the tube through with the compression ring on top and crank the compression nut down. A slight flare is added to the top to keep the fuel pick-up hose from slipping off and a slight angle on the bottom to keep it off the bottom of the tank. The return to the tank is very simple, just a reducer bushing with a hose barb. The return fuel sprays into the tee fitting and runs down inside to the top of the tank. Great circulation.

 

Fuel Filter, Pump, and Plumbing

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The Acme Fuel Polishing System designed by Wily Coyote, is completely fabricated as a module by using a plywood backboard. I used the Gulf Coast O-1JRF filter and the so familiar Walbro Pump. I choose the O-1JRF for two reasons. I’m frugal, $104 vs. $495 for the F-1, and space. The O-1JRF uses Scott 1000 Toilet Paper as a filter media. It will take the fuel down to 1 micron. I was concerned about the differences in the two, so I spoke with Gulf Coast about filter capacity and longevity. I expect I’ll go through more Toilet Paper rolls than a diarrhea ward after a greasy chicken dinner when I first turn it on. But after the initial de-sliming of the tanks, it will taper off. The big F-1’s will last longer between changes since they use paper towels, but the Acme system is totally independent of the main fuel system it does not need to be concerned with flow rates, the smaller filter will work fine. There is one other disadvantage, and that is there is no chamber for any water accumulation to be drained, but that, if any, will be absorbed into the toilet paper media.

Next is the pick-up and return valves. I used Tempo three way valves. You can see by the picture how simple it was. The Tempo valves are fed from the rear and the selector lever points to the flow input or output. The tee between the filter and the pump is for a vacuum gauge, which is installed on a plastic panel which I fabricated at the lower station. This gauge, beside the Intermec Spring Wound 12hr. Timer, tells me when the filter needs changed. If you are among the ones having a single tank, and that tank has a plug as described above, you won’t even need valves. The same is true if you make this a portable solution.

All in all, I have about $104 in the filter, $146 in the pump, $65 in the vacuum gauge, $80 in fittings, hose, and timer, and $5 for the beer. That’s $400, wait a minute, I thought this was going to be cheap.