RE: Pressure tap for Turbax1 ducted fan unit
Daan,
I agree with Paul Gray in that fan pressure is better suited for most glow DF installations. Pipe pressure is greater but causes swelling of the fuel tanks and varies greatly with throttle settings. Also, if the pipe loses seal, then the pressure dimishes which usually results in an overlean condition. Ilogged countless successfull flights with Turbax I fan using fan pressure with the K&B 7.5 DF engines along with the Fan Jett 50 engine. However, fan pressure did not seem to work as well with the Viojett or Viofan and BVM 72/81/91 engines due to a low pressure rise in front of the stators.
I do recommend an inflight mixture control, either JMP or BVM, to remotely control the mixture as the fuel level burns down-it will definately save your engine from an overly lean run and possible damage ($$$) as a result.
Art ARRO