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Diesel return pipe

Diesel return pipe

Diesel return pipe

(OP)
I am just in the process of installing a twin tank conversion on my wifes 1998 1.8D ford fiesta.  I have installed a seperate veg oil tank in the boot and ran a fuel pipe all the way to the front.  The only thing is once the car is running on veg oil, just before she gets to her destination she will need to flush the system so no veg oil is left in there to go cold and cause problems.  The way I have thought about doing it was to use a solenoid valve on the return pipe which when running normally will take the returned fuel and put it back into the IP so in theory it will be a short loop, then when she nears her destination she switches back to diesel and presses a button which sends the returned fuel back to the tank for a timed period so flushing out the veg oil.  

My problem is I only ran one pipe from the veg oil tank in the boot.  This means either me under the car again or let it flush into the diesel tank, I cant see to much of a problem because it will only be a small amount of veg oil going in and it's fitted with a bosch pump so should handle it.  

Questions are:  
1) Is the short loop theory ok to use.
2) I would just like a second opinion on the flushing back to the diesel tank instead of the veg oil one.

RE: Diesel return pipe

Get back under the car and finish the job.

The problem with short circuiting the return line is that in cold weather the Diesel fuel will gel in the tank and in the fuel supply line without the heated bypass flow.  The alternative is an immersion heater in the tank and electric heat trace cord around the fuel line.  Your choice...

On the veg-oil side, the problem is worse.  You might go to the trouble of using plugged crosses instead of elbows where you can, so you can rod out the goo while the car is alongside the road between Frozen and Nowhere.

Make it easy on yourself; who's she gonna call?

 

Mike Halloran
Pembroke Pines, FL, USA

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