gbitzer
Member
I've always loved the idea of putting smoke in my RV. I built it 15 years ago as an IFR traveling machine but still wanted this capability. After my first exposure to Smoke Oil I decided that I had to find a way to add oil without access to the cockpit. This stuff is tough to clean up. With the help of Marvin Homsley at www.smoke-system-helper.com I was able to get a 4+ gallon tank fitted only with NTP fittings. This required a new way of adding oil to the tank. I decided to add a recess in the belly of the plane where I added a quick release fitting (male). It is mostly hidden from sight and allows me to quickly connect a female fitting and suck oil into the tank with Marvin's standard diaphragm oil pump.
Now came the challenge of easily switching the plumbing from "Smoke Mode" into "Refill Mode". Although diaphragm pumps are very reliable they only pump in one direction. I was able to insert the diaphragm pump into the floor under the passenger seat and wanted to contain all of the plumbing in that area. My first attempt utilized (2) 3-way electric solenoid valves. These worked great but the flow rate was restricted. Even after modifying the bore of the valve I was not able to get the flow rate that I wanted.
My next attempt involved replacing the solenoid valves with 1/4" L Rotary valves. These were a little tough to find. However their size simplified the plumbing and reduced weight.
The initial test flight proved that these valves would provide adequate flow. One warning, if you try this be sure to mark the valve stem to determine the position of the valve selector. I inadvertently misaligned one of the valves during testing. This resulted in 2 gallons of oil being pumped onto the hangar floor. 1 hour later I was back into the project and corrected the valve position. The next step was to add a simple mechanism for changing the position of the Input and Output selector valves. A little scrap aluminum was fashioned into control horns that were riveted to the slotted valve handles. A selector "T" handle was welded up from 5/16 rod. The selector handle stays mostly out of sight in the baggage area. It is easy to pull which rotates the valves into "Refill Mode".
Many thanks to Marvin for his assistance in modifying one of his beautifully welded aluminum tanks and for all of the plumbing parts. By the way, the smoke has proven to be a real benefit when entering the busy approaches at OSH and other fly-ins. A good RV is never really finished.
Now came the challenge of easily switching the plumbing from "Smoke Mode" into "Refill Mode". Although diaphragm pumps are very reliable they only pump in one direction. I was able to insert the diaphragm pump into the floor under the passenger seat and wanted to contain all of the plumbing in that area. My first attempt utilized (2) 3-way electric solenoid valves. These worked great but the flow rate was restricted. Even after modifying the bore of the valve I was not able to get the flow rate that I wanted.
My next attempt involved replacing the solenoid valves with 1/4" L Rotary valves. These were a little tough to find. However their size simplified the plumbing and reduced weight.
The initial test flight proved that these valves would provide adequate flow. One warning, if you try this be sure to mark the valve stem to determine the position of the valve selector. I inadvertently misaligned one of the valves during testing. This resulted in 2 gallons of oil being pumped onto the hangar floor. 1 hour later I was back into the project and corrected the valve position. The next step was to add a simple mechanism for changing the position of the Input and Output selector valves. A little scrap aluminum was fashioned into control horns that were riveted to the slotted valve handles. A selector "T" handle was welded up from 5/16 rod. The selector handle stays mostly out of sight in the baggage area. It is easy to pull which rotates the valves into "Refill Mode".
Many thanks to Marvin for his assistance in modifying one of his beautifully welded aluminum tanks and for all of the plumbing parts. By the way, the smoke has proven to be a real benefit when entering the busy approaches at OSH and other fly-ins. A good RV is never really finished.
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