Need some advice on what type of fuel level probe should I install in Lancair 360 with extended fuel tanks and no header tank.

Mike,

 

Depends.

 

I have found that the VM fuel system is extremely accurate if one is careful when calibrating the system.  I have been using such a system for ten years.  If you use the VM system or some other probe system, the following comments still apply.

 

One way is to use probes only in the main tanks, especially if there is only one fill opening for each wing in the outer bay.  The exact extra fuel amount may not be important to you, only that in the mains.  Another is to put probes in the main and outer bays with a switch to select which tank is being displayed.

 

Of course you have built slosh tanks with doors into each wing root.  It is still important to test the unusable fuel amount (on the ground) by tilting the wings in an extended climb and descent attitude and pumping until air is drawn.  This is so you know how much fuel is the minimum if that wing is selected for a takeoff or landing.