To accomplish moving the oil pressure sending unit, Aircraft Specialty came to the rescue. Aircraft Specialty has a kit developed for the RV-12 to move the oil pressure sending unit to the firewall. The kit includes an adapter fitting for the block of the Rotax engine, a restrictor fitting, Teflon hose and an adapter fitting for the oil pressure sending unit. Because I was striving for an aesthetically pleasing mounting for the oil pressure sending unit, decided on making a modified dual sending unit bracket so both the fuel and oil pressure sending units can be mounted together on the firewall. Because this mounting is at a different location, Steve at Aircraft Specialty sent me all the fittings and suggested I remove the sending unit from the engine, install the fittings and run vinyl tubing between the fittings to determine the exact length of hose necessary … then return the fittings back to Steve so a custom oil pressure hose can be fabricated.
Following Steve’s suggestion, the fittings were installed on the engine and a piece of vinyl tubing was attached and routed to the new home for the oil pressure sending unit on the firewall and a measurement was made for the amount of hose necessary. Also of note, the Rotax Illustrated Parts Manual shows Loctite 243 used on the oil pressure sending unit’s threads, so the threads on the fitting installed in its place had Loctite 243 applied to them. Initial thoughts were to run the Teflon hose under the engine but after thinking it through, decided the safest route was to run the hose up and across the top of the engine where it can stay cooler and away from the heat of the muffler and exhaust pipes.
At the firewall, an adapter fitting will sit in the rubber grommet and serve as an interface between the oil pressure sending unit and the Teflon hose fitting. The fitting used for measurements in the photo below is a 45 degree fitting … however, the Teflon hose will be made with a 90 degree fitting for the firewall connection.
Decided for my application the actual length of the hose material not including the fittings needs to be 37".
Return from the future:
The changeover to Aircraft Specialty’s remote oil pressure sender kit has finally been completed (well almost). Covered on a posting February 5, 2016, felt it would also be best if I were to return from the future and edit this post as a follow-up on installing the remote oil sender hose from Aircraft Specialty ... especially since this entire post covers their remote oil sender kit for the RV-12. As mentioned earlier, measurements were taken using a vinyl hose so Aircraft Specialty could make a custom remote oil sender hose for the DOG Aviation RV-12 utilizing a different fitting and length than the one they would normally supply in their retrofit kit. The reason for this, as mentioned earlier, is because a special mounting bracket was fabricated so both the oil and fuel pressure sending units could be mounted together in a bracket on the RV-12’s firewall. After measurements were taken and passed on to Steve at Aircraft Specialty … three days later, DOG Aviation’s receiving department took delivery of a custom, quality built, conductive Teflon hose in fire sleeve. Have to say, the customer service from Steve and follow-up has been nothing less than outstanding for each of the five kits that have been purchased from Aircraft Specialty for the DOG Aviation RV-12 … Teflon brake line kit, Teflon fuel line kit, Teflon remote oil pressure sender kit and the totally slick canopy locking system.
There are two mounting options possible with the hose I ordered … depending on the final location for the voltage regulator. If the German built Silent Hektik (or Ducati) voltage regulator is mounted using the old mounting location on the firewall shelf reserved for the voltage regulator, the remote oil sender hose can be routed across the top of the Rotax engine, down under the engine mount and then sweep over to the oil pressure sending unit on the firewall. This arrangement still allows for a cooling cap to be installed over the regulator and room for the cool air blast tubing to supply cool air to the regulator.
The other option available which is likely better (especially for those who have followed Van’s latest mounting instructions to move the voltage regulator under the instrument panel shelf) is to run the hose for the remote oil pressure sender following the same path as the hose for the fuel pressure sending unit. The hose length I chose will work for this route, but ideally could be an inch or two longer.
At this point in time, the final decision has not yet been made on where the voltage regulator will be mounted, so only the engine end of the remote hose will be tightened ... the fitting on the sending unit will remain loose until a final decision is made regarding the location of the voltage regulator … which will dictate which way the firewall end of the remote oil pressure sender hose needs to be routed.
