Plantoil/diesel conversion basics
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wood4sheep

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Posts: 2
Reply with quote  #1 

okay I read thru the other posts here and your email and want to follow up with to request a clarification of what would progress the greasecar kit to a more refined process on a 1991 vw jetta non-turbo 1.6l.  Please realize I  am lay person here!!!

from your post:

A:1. Get VO temps as close to 300°F as possible prior to injection.
2. Never run VO(whether hot or not) in an engine not up to full operating temp.
3. Make sure your VO fuel contains less than 300ppm of suspended water. (It degrades injector performance fairly quickly)
4. Make sure that your injectors are always operating within spec.
5. Make sure that your injection timing is within spec.

 


and from your email on dewatering:
That creamy layer on the bottom is probably high fat or hydrogenated wvo which also tends to settle to the bottom along with water. Not pouring that layer into your processing unit is probably a good idea since you are using the resulting fuel in a VW diesel converted with a kit that has a design which is relativly crude. VW diesels require high quality VO fuel AND as modern a conversion as feasable ..as well as very careful engine management to obtain a full recovery of conversion costs.

okay.......................

1.  I need to please get clarified what HIH and HOH mean.
2.  It sounds like heating the tank beyond a certain temp increases poly issues and is not a good idea so:
    a.  heating tank some is needed or no need to heat tank at all? or need to be able to adjust?  need temp gauge for tank?
    b.  heated pickup in tank is the way to go?
 3. heating the oil to as close to 300 degrees is best?
    a. can you clarify or synopsis the best way to do this.   Is this by flat plate? but flat plate from cooling system can only hope to get to close to the temp of the cooling systerm. so....electric?
    b.  the current setup I have from grease car leaves lots of line from the heating point.  I have lots of issue with this which I think needs to go to a whole seperate point so....
4.   so much fuel line after the heating point !!!!!!!!!!
    a. I noticed this and shortened lines as much as possible and slipped leftover coolant hose on them as insulation to protect from heat loss.
    b.   the tempurature gauge is after the heated area.  It cant give a proper heat reading when the oil is not flowing.   It gives a low reading until the oil flows so how can the copilot computer really know when to switch?
5.  purging....
    a.  they say to set the purge when there is no full hydraulic system in place.  in their set up you time how long it takes to get deisel from the deisel return to the tank before you have vegi in the line.   This must be a different time from the time when it is a full hydraulic pressure and pushing against vegi oil.
    b. purging the line does not purge the pump and injectors.   It seems to take much more to purify them.   would it be good to have a pump just for the purge cycle to push deisel quickly thru the line and then give the pump the most time to purge. and how do you determine that time to actually get deisel into the injectors?
6. filtering.   this seems seperate and needs to do a quality job of reducing impurities and water. but is its own topic probably generic to all.

okay.... very interested in pulling together an improvement.  Thanks so much for any help!

Dave

danalinscott

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Posts: 934
Reply with quote  #2 
Quote:
1.  I need to please get clarified what HIH and HOH mean.
 


From the "terms" section
 Hose On Hose- Heated VO fuel lines consisting of lines which hot coolant flows through bundled with  line(s) that VO/PO flows through. Often the entire bundle is sheathed in insulation to conserve coolant heat.  HOH lines are usually intended to liquefy any VO which has solidified in the line during the time the engine has been shut down and to slightly warm the VO as it travels toward the engine from the VO/PO tank.

Hose In Hose- Heated VO fuel lines consisting of lines through which VO/PO flows completely encased in a larger line that hot coolant flows through. Also known as Tube IN Tube.  HIH lines usually  add more heat to the VO flowing through the fuel line than HOH and are often also sheathed in insulation to conserve coolant heat. 

Quote:
2.  It sounds like heating the tank beyond a certain temp increases poly issues and is not a good idea so:
    a.  heating tank some is needed or no need to heat tank at all? or need to be able to adjust?  need temp gauge for tank?
    b.  heated pickup in tank is the way to go?
 


Unless you only live and drive in a climate that is always warm enough for your wvo fuel to remain fully liquid (like Hawaii) you need some way to heat the fuel in the tank so it easily flows from the tank into the fuel lines.
A heated fuel pickup is the best option. One with a thermostat which limits the tank temp is best..but this is not an option with any current kit.

High VO temps speed up the polymerization reaction..but unless you tend to run your tank at near empty all the time or fail to empty and flush the tank when you leave the vehicle idle for a few hot months that really should not create any serious problems. The VO polymerization issue was blown WAY out of proportion by Chris Goodwin (Frybrid) as a marketing tool. Keeping your fuel tank full is the easiest way to avoid fuel tank poly issues.

Quote:
3. heating the oil to as close to 300 degrees is best?
    a. can you clarify or synopsis the best way to do this.   Is this by flat plate? but flat plate from cooling system can only hope to get to close to the temp of the cooling systerm. so....electric?
 


If your conversion does not currently use a FPHE (Flat Plate Heat Exchanger) I strongly suggest adding one. Check out the Component Vendors for a link to the best prices I have been able to find for those. A FPHE will heat your VO fuel to as hot as you can git it using coolant heat. That is as hot as you want to run fuel through your IP anyway. To get VO fuel hotter before it is injected you have use electrical heaters on the injector lines. These are referred to as Injector Line Heaters (ILHs) and there are two types available. One is a very crude DIY unit which due to low efficiency can only add about half as much heat per watt as the other. Based upon side by side testing I cannot recommend those for VW diesels.

I DO recommend the ILHs sold by Injector Line Specialists and there is a link to their website in the Component Vendors section. And I offer a wiring harness for ILHS that simplifies installing them. That too is linked to in the  "Vendors" section.

Even if you decide not to install ILHS I recommend at least insulating the injector lines. Doing so will help retain the heat added to the VO fuel prior to the IP significantly. A lot is lost to air passing by the bare steel lines...especially in cold weather.  It is not as hot under the hood as you might imagine when a car is running down the road.

Quote:
the temperature gauge is after the heated area.  It cant give a proper heat reading when the oil is not flowing.   It gives a low reading until the oil flows so how can the copilot computer really know when to switch?
 


I don't know.
That would be a question that only Greascar might be able to answer.

Quote:
5.  purging....
    a.  they say to set the purge when there is no full hydraulic system in place.  in their set up you time how long it takes to get deisel from the deisel return to the tank before you have vegi in the line.   This must be a different time from the time when it is a full hydraulic pressure and pushing against vegi oil.
b. purging the line does not purge the pump and injectors.   It seems to take much more to purify them.  
 


I don't think I understand exactly what the procedure you are describing consists of. Can you quote the manual exactly on this? Some kit vendors seem to believe that if most of the VO is replaced by a blend of VO and diesel it is "good enough". But to obtain maximum engine life on VO fuel the purge must be complete. Starting a cold engine on even a 5% VO/diesel blend  can significantly shorten engine life. You may want to double or triple the suggested purge time on a VW.

Quote:
would it be good to have a pump just for the purge cycle to push deisel quickly thru the line and then give the pump the most time to purge. and how do you determine that time to actually get deisel into the injectors?
 


I don't think a separate pump would help much in terms of shortening the needed purge time. When you switch from VO to diesel the line from the solenoid valve to the IP must first be purged...then the VO in the IP is slowly replaced since the VO present and the incoming diesel mix a bit as the purge takes place. Little by little the blend goes from mostly VO to mostly diesel...but it may take a very long time for the VO to be completely displaced.  While this is taking place the "blend" being sent to the injectors (and the return line) has a progressively smaller % of VO...but it takes quite a while to get it to 100% diesel fuel.

Optimally this blend is not sent to the diesel tank since this contaminates the diesel tank with VO and the fuel the engine starts on is then a VO blend..which must be avoided if maximum engine life is important. I don;t know if Greasecar has updated its kit configuration to avoid that by adding a delay so all purge blend is sent to the VO tank or if they still use a configuration that send the blend to the diesel tank. But it would not be hard to determine.

Quote:
6. filtering.   this seems separate and needs to do a quality job of reducing impurities and water. but is its own topic probably generic to all 


It is ..and there is a section on dewatering HERE.
Filtering is pretty strait forward. You need to pre-filter to approx 10 microns prior to dewatering via settling or it will take much longer. You must then filter to the micron rating (or better) of your vehicles stock diesel filter AND make certain that the onboard VO filter is the same micron rating as that one to avoid the small problem of plugging your onboard VO filter..or the serious problem of sending larger particles through your IP than it was engineered to handle without excessively rapid wear.


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Dana danalinscott@yahoo.com
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