There's been quite a few debates about those valves in the past and I thought I could share my experience.
Basically it works fine and is still a good value BUT when purging it does send some of your wvo back into your diesel tank. I've experienced it since I've installed mine and it was confirmed by a mechanic that makes a living of installing wvo kits using that valve as well.
Summer time is not a big deal as some wvo in your diesel actually makes your van runs very smooth but comes winter you might experience more difficult starting. On mine when it's cold it smokes more at start up (not black but lighter) and probably wears the engine faster than expected. So I simply drain my tanks twice a year and use the contaminated diesel and mix it back into my wvo tank at a 20% rate.
For me it's not worth to re-do my valve setup but people thinking about it might reconsider 2x 3 way valves vs 6 way valve. And if like me you're already using the Pollack well consider draining your tanks a few times a year. Cheap and easy insurance!
Edward at Plantdrives could chip in or others in the know.
I have 2 cents to toss in here: my wife's NB TDI has done almost exactly 160K km on WVO. It was originally set up with a pollack 6 way. It always worked, and still switched even when I was replacing it. But about 15K ago, I believe it started to bleed a little bit of WVO into the diesel side, and vice versa. It finally simply wouldn't keep a constant flow, bleeding air somewhere internally. I always considered it to be the weakest part of this particular setup, but thought it worth the experiment to run it to failure. I would not use one again. I now use a 2 electric pump system, and a single greasecar 3-way to switch the return. No more problems. It did last 160,000 km, which is a heck of a lot better than most of the other 'bosch' electronics in the car, so I can't really complain.
Last edited by winelover on Thu Apr 29, 2010 2:07 pm, edited 1 time in total.
I have to concur with David's assessment of the 6-port valve vs. two 3-port valves. The WVO flush into your diesel tank isn't a huge concern in the summer, or if you keep your diesel tank filled up in the winter, but it will lead to harder cold starts. The more you switch back and forth, the more WVO is being flushed into your diesel tank. If you do long hauls and are only switching every 100km or so this is not every going to be a big issue. It is the shorter trips that get you.
I'm installing my old Plant Drive kit on my new L400 and I'm seriously thinking of buying two 3 port values to replace the 6-port. The only reason I wouldn't at this point is that I'm unemployed, building a house and 1/2 Scottish (basically $$). Definitely if I was starting from scratch I'd go for two 3 -ports.
I drive about 20 minutes each way, once or twice a day. I fill up my diesel tank when it gets to half, maybe a little under.
Never a problem as long as I do that, with the "6-port" setup (return a few ounces of veg to diesel tank when you get a purge...a FAST purge, BTW). A bit hard starting if I let it get really low. I graphed it once, to see the obvious...it's an exponential rise in WVO percentage as the diesel gets near empty. Easy to avoid.
Latest setup on my Deli, I did use 2 3-ports. This was to try bolting to VM2 filter all mounted under battery tray. Nice. See the pics on the blog, linked from the home page at plantdrive.ca.
But, when I wired them, how did I wire the 2 3-ports? Just like a 6-port! I wired them to one toggle switch.
Why? Because I knew full well I would not have a problem, it was simple, and I run to about -20C.
IF I lived on the Prairies, or someplace else with *really* cold winter temps, etc., I might have put on a controller or timer or at least the 3-way manual switch we sell.
But in this climate, it's definitely not an issue as long as you top up that diesel tank.
As for quality of valves, we maybe get one bonafide return of a bad Pollak per year and we sell a lot.
See the car on our home page, the one with over 500,000 km on WVO, in Ontario?
He's on his 3rd Pollak. Not bad. That's a lot of switching!
But, he went through 2 in really rapid succession after several years on the first one and no issues.
When questioned, it was revealed that he had decided to start switching much sooner, in winter. He figured that was what killed them, and I agree. So, he went back to waiting a proper time in winter to switch, and all was well again, as far as I know. The valves need a chance to warm up a bit from warm return diesel flowing through them.
We did have a few bad switches, it seemed, that come with them, a year ago. It seems to not have been an issue for quite a while now.
As for two electric pumps being better, I do not think so (IMHO).
I have seen and heard of a lot of electric pump failures. One is bad enough, I avoid them whenever I can and you do not need one on a good WVO system on a Deli which has a vane pump built into the end of the VE-style injection pump, as a lift pump to move fuel from tank to engine. Two electric pumps is worse. Twice the chance of a failure at pump or wiring or fuse. And in really cold temps, you will also be likely to quickly ruin all but the most robust electric pumps on cold WVO unless you provide some preheating (via a small electric pad heater, coolant loop, warm/protected placement, etc.)
Edward Beggs
PlantDrive.ca
Salmon Arm BC
SVO/WVO Kits, Components, Conversions, Consulting, since 1999. plantdrive.ca@gmail.com
the kits i install have two 3 port valves. the controller has a timer adjusted by a jumper that delays the return valve to allow purged fuel to return to the proper tank.
For anyone that wants three-ports...
Our kits are also available with two 3-ports, or three 3-ports (faster purge), and a full range of controller options.
The valves can be mounted to the VM2 filter.
The controller can be the 3-way switch, the "MFT" (programmable multi-function timer), or the VOController (full-meal-deal controller with a ton of features and a digital display for status, fuel temp, Vegtherm on/off, turbo timer, etc.)
These are all listed on our site. Along with the Pollak 6-ports.
Take your pick!
Edward Beggs
PlantDrive.ca
Salmon Arm BC
SVO/WVO Kits, Components, Conversions, Consulting, since 1999. plantdrive.ca@gmail.com
Although as I have mentioned we have had overall good success with the Pollak 6-port, as well as with the 3-ports we have been using up to now, there is a demand for a more economical 3-port valve with NPT ports that allow use of cheaper fittings than the ORB fittings we use (and like) on the current 3-ports.
So we'll be adding a valve like the one Omar has posted and it looks like we'll be able to stock in BC and offer at the same price or less.
We also are moving to a less expensive but good quality, easy to adjust, timer relay, than the current one, and I'll update the info on the site on that soon.
As well, we have added a new version of the 60 litre plastic tank that fits so nicely behind the rear seat of the Delica.
The tank is intended for the warmer regions, particularly the West Coast. It comes complete with a 1/2" draw tube installed and ready to go, with a 1/2" fitting that can be rotated.
You connect a single 1/2" line to supply veg to the front of the van.
A tank like this, in a trunk or inside a van, with 1/2" line, and a looped return, we have run in the past, to -10C.
Anyway I will update the thread when we get the new valves in stock.
Edward Beggs
PlantDrive.ca
Salmon Arm BC
SVO/WVO Kits, Components, Conversions, Consulting, since 1999. plantdrive.ca@gmail.com
They make this valve in 24v application, will you have those as well? I'm just about to go ahead with building my kit so would be nice to get locally... Also, Omar's got some heat exchangers, do they compare to the ones you have (any difference)?
any way have fun 
