Diesel engine fuel return pressure -- how high above the engine can the fuel tank be

Question

This is specifically regarding an inline six cylinder direct injection, external injectors, and injection pump. Circa 1998. Just a stock standard Diesel motor.... But in general also.

The bush camp I work at has 3 generators, the fuel tank is on a bit of a hill behind it, so the returning fuel has to be pumped up (by the FIP) maybe 6 feet. So basically the return line had 2.5 or 3 psi back pressure the pump has to overcome.

It seams odd to me, never seen a fuel tank above or (much above) the motor. Is this ok? What would the limit be?

Answer 1

Not MVMR but why not have a small return tank level with the engine and then a separate pump to pump the fuel back to the big tank when close to full. Would only operate sporadically.