Hello all,
Been awhile since I visited the Delica Site. Family and crunch time on house reno's have put the vehicle on the back burner. I tried many different ways to get rid of the air and realized that it may be bigger than that. So I decided it would be worth the time and money to go and see Bjorn auto in Cobble Hill. He installs plant drive systems.
So after spending 3 hours with Bjorn and going over the whole system, we found out what the problem was. The looped return was creating some sort of back pressure that made the pollack valve open slightly on the diesel side and pulled diesel in, not allowing the veg to come through (Kev, you may recall we had that issue when you and I tried to use the suction gun at my place) The looped return also allowed the air to just travel around the system. Even if I got all the air out now, when I did a filter change I would be back at square 1. Eric, I know you mentioned that to me.
So this is what Bjorn came up with. Put a shut off ball valve before the brass tee on the looped return and tee off the return line and run back to the tank. That is what most people do anyways in other systems. But with the ball valve he said that I could bleed air to the tank when it was fully shut, and crack it a 1/4 when air is out. That way I still get a bit of a looped return and also create some counter pressure to ensure the pollack valve works correctly. We did a test and clamped the return line shut and then created suction in a jar with a shop vac, the veg oil started moving through the lines as we could see through the glass filter I installed right before the Vegtherm. So that was the first time I really had veggie oil through the entire system.
He did not have the fittings but I left his place with a game plan and hope to get all the pieces in the next few days and get it done!.
He wrote me today and had a few after thoughts which I will share.
1. Your Vegtherm is unregulated (no thermostat) and will therefore heat constantly when switched to vegetable oil. To avoid overheating the Pollock valve it would be better to install the Vegtherm after the valve and immediately before the pump. This means it has to be on the two port side of the Pollock valve.
2. I usually install the looped return in a way that it re-enters the intake stream before the filter. It is not essential but it provides additional safety if any metal filings or rubber pieces should come loose.
I also got to see a Mercedes he was converting. He was installing an Elsbett single tank system. He said he likes the plant drive much better.
So I will post when I finally get up and running. ONe benefit to all of this is that I know this system in and out.
Sean
"I find television very educating. Every time somebody turns on the set,I go into the other room and read a book."
Groucho Marx