BIODIESEL & SVO DISCUSSION FORUMS





Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Straight Vegetable Oil (SVO) as fuel  Hop To Forums  Two Tank Systems    To return or not to return?
Go
New
Find
Notify
Tools
Reply
  
To return or not to return?
 Login/Join
 
Member
posted
Hi,

Running on a two tank system for a bit more then 2 years. I run it on a 1996 Toyota Hilux non turbo. So far my setup is: No heating to vegoil tank, a cross barbed fitting which supply's heated coolant to both heat exchanger and the filter coolant wrap, one pevekoil valve and fully looped return. Recently added a vacuum gauge to monitor filter and oil resistance. I live in a rural area and 2-3 km seems to purge the fuel system enough for a nice start up. Cool to warm winter with rare light frosts(the oil is always liquefied.
I had an IP rebuild once but it had 400,000 km on it any way. Also the injectors. A compression test showed up pretty good.
We got another diesel now which is a 1999 VW polo classic - has a combined mechanical and electronic injection with an ECU(non turbo).
This drives me to upgrade my current conversion on the hilux and install a perfect conversion on the VW.
It doesn't seem I need to heat the vegoil until the engine compartment just from observing the vacuum.
My main concern and questions are regrading on how to handle the return fuel from the IP. From doing some research on the net I understand the returning diesel to the tank serves some or all of this purposes:
- cool down the fuel for a more efficient combustion- less fuel per KM.
- cool it down to keep the lubrication properties high and protect IP internal.
- cool down injectors?
- purge any air that might have entered.
- gathering any impurities around the injectors?

The thing is I think it might not be the best idea to return any fuel to the diesel tank because every time you purge differently, meaning: sometimes you purge when going up hill , sometimes down hill, some times in traffic , etc... You can never be sure you purged vo completely out of the lines and when you get back to diesel you might have some vo go in the diesel tank.
Im thinking of two options:
Option 1- Having diesel and vo looped and only returning to vo tank when purging. Using two valves, concerns are: Heated diesel, although my guess would be that it is insignificant at the beginning of the ride when the engine is still cool and also when purging most people with two tanks would purge with hot diesel that has heated up in the lines/valves/filter while driving on vo. I can always add a few % of Biodiesel for lubrication and monitor air with clear section of hose or/and an inline filter.
Another thing is the bit of vo which would stay in the short section between the return valve and the intake line to the IP so when returning back to looped diesel you will have it draw in(am I clear?)

Option 2- Using three valves to handle both fuels and try to have all the options including return to diesel tank when needed. This would be a lot of plumbing.

What is the most current up to date setup that is recommended?

Also my plan is to have the FPHE and heated filter in series very close to each other so I would think restriction would not be significant.

One last thing, I am thinking of getting one of Elsbets's modified injector tips and glow plugs for the VW since I am worried about injection timing with the ECU and the injector tips should have a good effect on it. Any thoughts about this would be appreciated to.

Will probably add Injector line heaters to the VW.


Any thoughts or comments will be appreciated,


YTK

This message has been edited. Last edited by: ytk,
 
Registered: September 28, 2013Reply With QuoteReport This Post
Member
posted Hide Post
Any one?

This message has been edited. Last edited by: ytk,
 
Registered: September 28, 2013Reply With QuoteReport This Post
Member
posted Hide Post
What part of the world are you in YTK?

I have an Elsbett kit on a 1997 Passat 1.9tdi. I'm not using the car anymore. So if it is of interest to you, let me know.
 
Location: Ireland | Registered: January 20, 2012Reply With QuoteReport This Post
Member
posted Hide Post
A lot of people are using three valves especially in colder climates. I use three and have 10 second flush times. My 2005 E320 CDI uses a 70 psi veg pump that changes many things. I loop the veg behind the fuel pump. This is basically returning to tank on purge. The diesel returns to diesel tank. When my system turns on the #1 switch(valve) goes from diesel to veg, #2 switch(valve) is return and goes from engine to behind the veg filter instead of returning to diesel tank. #3 switch(valve) creates a loop so that the diesel fuel pump in the tank is still running while the car is running and the diesel just goes back to the diesel tank. There is a T in there also that makes this possible.

In USA we do not have Polo's or Toyota diesels. If you use two switching valves it is not that hard to just return to tank for both sides. When you purge the veg return is still returning to the diesel tank. But don't flush to long or you will fill the veg tank with diesel which defeats the point of running veg. The best way to test flush time is to have an empty veg tank turn on the purge mode and time how long it takes for diesel to go into the veg tank. It was 5 seconds for mine I flush for not more than 10 seconds just to make sure. I also try to drive in diesel mode for at least a few hundred meters before turning off the motor.

Hope that helps.

This message has been edited. Last edited by: maddasher,


Robert
In Fort Lauderdale running a 2006 Jeep Liberty CRD 2 veg tanks HOH 2 upgraded greasecar vavles 3/8 fuel line 5/8 heater line HOH Hose wrapped filter. Injector Line heater on the Common Rail. 2nd car 2005 Mercedes CDI, Raw Power fuel pump, 36 gallon veg tank in trunk coolant heated HOH, rubber hose wrapped fuel filter, FPHE, 3 greasecar valves, Common rail line heater.
 
Location: Ft Lauderdale, FL | Registered: June 01, 2002Reply With QuoteReport This Post
Member
posted Hide Post
2tiredkl Im in Israel...

maddasher, Thanks for the answer. I cant really imagine how can someone get a 10 second flushing time. In my Toyota Hilux the IP is what pulls the fuel from the tank so its on vacuum. But even if you have the inlet valve and return valve as close as possible to the IP, once you turn to purge mode you still have all the VO in the IP ,in the injector lines and return from injectors, how is that clear of VO in 10 seconds? Is it to do with the high pressure pump?
 
Registered: September 28, 2013Reply With QuoteReport This Post
Member
posted Hide Post
It is a 70 psi pump. It is like turning on a small garden hose. Try the test from my last post and you will be amazed how much gets pushed back to the tank. It was not an effective test on my wife's Jeep. It has two WVO tanks one is heated and the other just drips into the heated tank. That one does not use a pump but it flushes quickly also. Both basically return to the veg tank, more accurately they return to a T between the veg tank and the veg filter. When purging the only place for it to go is back to the veg tank.

Here is a link to Jeep. Jeep CRD


Robert
In Fort Lauderdale running a 2006 Jeep Liberty CRD 2 veg tanks HOH 2 upgraded greasecar vavles 3/8 fuel line 5/8 heater line HOH Hose wrapped filter. Injector Line heater on the Common Rail. 2nd car 2005 Mercedes CDI, Raw Power fuel pump, 36 gallon veg tank in trunk coolant heated HOH, rubber hose wrapped fuel filter, FPHE, 3 greasecar valves, Common rail line heater.
 
Location: Ft Lauderdale, FL | Registered: June 01, 2002Reply With QuoteReport This Post



Member
posted Hide Post
A suggest: install an in-line sight glass on the RETURN fuel line from the IP to the return solenoid. Run the engine at 1K to 15K. Count the seconds when the color changes from dark (VO) to light color (D2). Remove the sight glass if it is no longer wanted/needed.
 
Registered: October 30, 2005Reply With QuoteReport This Post
Member
posted Hide Post
Sorry about the RPMs... Meant to say 1500 RPMs.
 
Registered: October 30, 2005Reply With QuoteReport This Post
  Powered by Social Strata  
 

Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Straight Vegetable Oil (SVO) as fuel  Hop To Forums  Two Tank Systems    To return or not to return?

© Maui Green Energy 2000 - 2014