Good Day All,

I've bashed together a one-off push/pull twin. The aircraft employs two 0.40 size motors from different manufacturer's.

I'm having trouble with the fuel system plumbing.

Currently I'm using one fuel tank to supply both engines, and have both engines supplying exhaust pressurization to the single fuel tank. The fuel supply line originates from a single tank clunker and splits to two lines by using a fuel line splitting "T". The fuel lines then run from the splitter "T" to each engine.

Additionally the engine exhaust port pressure supply lines each flow through a one-way valve prior to connecting via an in line "T", and then provide pressurization to the fuel tank via a single pressure hose.

I tried the first test engine run today and had a variety of troubles. Firstly, the tail engine ran rich to the point of quitting when I tilted the aircraft nose up (i.e. engine lower than the fuel tank). I suspect that the siphoning effect of the fuel from the tank to the engine resulted in just way too much fuel arriving at the carb. Any thoughts on this?

Additionally, I had a great deal of trouble trying to start the second engine after the first one was running. The problem seemed to be that the fuel tank pressurization from the operating engine was so great, that the fuel to the engine being started was over supplied (i.e. flooding). In fact, I was often getting hydraulic lock on the second engine during start attempts.

This is my first attempt at operating two engines simultaneously from one tank. What am I doing wrong?

How should I set up the fuel system in order to run two engines in a push/pull configuration?

I have two Perry Fuel pumps, but have not installed them yet. In fact, I don't have any experience with Perry style fuel pumps. Would these pumps eliminate the requirement for fuel tank pressurization? Would Perry pumps (one for each engine) provide a metered flow of fuel to the engine avoiding the change in mixture that results when the aircraft pitch is changed from nose up to nose down?

Any help from the experts out there would be greatly appreciated.

I'm struggling but having fun.

Cheers,

Marcus.