At 09:14 AM 2/8/2014, you wrote: >I'm going to opt for a GPASC flywheel drive engine on my >KR2. So the question is, mechanical pump or electric. I'm thinking using >electric pumps instead of the mechanical for the ability to have a backup >pump. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Will you have a header tank with gravity feed? If so, you really only need an electric pump for backup and perhaps takeoff and landing when head pressure may be less than optimum. A pressure regulator may be in order also, depending on the pump selected. I have outer wing tanks only, no engine pump on my 0-200 and use two electric pumps, in parallel, with a pressure regulator set to 4 1/2 pounds. With that type of setup you really need a backup system. I use a small 4 AH battery with separate buss, switches, and electrical isolation. I needed my backup at 10 hours into testing when I lost my main electrical buss. A simple flip of the switch and the engine never sputtered. I can pump from either tank with either or both pumps. I can also flip a switch and charge the backup battery in flight. My setup has served me well for 500 hours now and saved my bacon when I needed it. Further details if desired........... Larry Flesner
