Okay... This is going to get long quick. I bought a 75 240D some time ago that already had a WVO kit in it. It worked fine, but the engine in the car was in terrible shape and eventually got to the point it did not have enough compression to start at all. I loved the car so much that I bought a 83 300D turbo diesel to replace it. Much better shape, and a _lot_ more power! So... I am in the process of swapping out the kit... But I might want to make some changes. I think the old car might have been a greasel kit, it uses the 3 hose stuff. The setup in the car goes something like this.
-Heat exchanger in tank
-Coolant lines for exchanger spliced in hose going to firewall and other end goes somewhere near passenger side on engine block
-Filter with a heater wrap thing on it from output of tank
-Small electric pump on out of filter
-3 hose bundle routed out of trunk below the rear seats (yes, hoses are inside car!), go into hole created on driver side of center dash, near transmission
-Electric fuel selector solenoid valve, input from diesel fuel filter and WVO tank.
-Output goes to lift pump on IP
-All returns (IP, injectors...) go into 3 way brass valve. Valve switches form returning to diesel tank and a splice made in the input to the lift pump. I assume this is to make getting air out easy.
And all the electric stuff (solenoid, heater, fuel pump) are turned on by a single switch in the cab. There is also a fuel pressure gauge in the cab, with a line for that spliced in the WVO supply.
So.... I would prefer not to run the hose in the interior again. I thought that was a pretty crappy way to do it. I doubt I will have enough length to go under the car, and it might be hard to route since the bundle is kinda big. I was thinking I really should only need a fuel line coming from the tank and put everything else in the engine compartment. I can get some fuel line cheap, and should be easy to run under the car. Would it work okay to setup the fuel input and return the same, and have the pump and filter mounted in the engine bay? Do I still need to have a heat exchanger, or will the fuel return and filter wrap heater be enough? If I do need more heat, will a inline coolant heater be best? Or maybe a coolant based heated filter?