Waste Vegetable Oil

[wvo]

I am installing a vegetable oil kit on my 6.2L. With the kit you end up with two seperate fuel systems before the pumps. Start on diesel and then after it warms up you can switch to vegetable oil, then switch back to diesel before shut down, to purge the lines and pumps. The whole trick with running on vegetable oil is keeping it hot in the tank, lines, filter(s) and then delivering the oil to the injection pump at about 180 degrees.

I think the original system on my '82 Suburban goes:

Tank - Primary Filter - Lift Pump - Secondary Filter Injection Pump.


I think I will have to re-route the fuel lines so that the diesel goes:

Tank - Primary Fiter - Secondary Filter - New Fuel Selector valve - Lift pump - Injection Pump.


And the vegetable oil will route: Heated Tank (Cooland exchanger core) - Coolant heated line - Cooolant Heated Filter - New Fuel Selector Valve -Lift Pump - Injection Pump.

The return line has a three-way valve that allows you to purge like it is originally set up for back to the diesel tank. And then when all the air is out you can switch the three-way valve and direct the return fuel back in a loop to just in front of the New Fuel Selector Valve. That way you don't get vegetable oil going back into your diesel tank.

Anyway I put this post up because "I think" alot and I was hoping that the experts here that know (Not think like me) would see problems with this plan before I run into them.

One main question I have is that the coolant heating seems like it will handle the oil OK up to where it routes into the line going to the Lift Pump. Thats when I was concerned about the vegetabel oil cooling down on it's way through the Lift Pump and then over to the Injection Pump. I think (Thinking again) that with the re-routing I wil have to do, the vegetable will go into the line that come out from under the air filter pointing at the Primary Filter. From there it will go along the top of the block to the Lift Pump in front. Then back through a line along the top of the block toward the Secondary Filter. Then loop back (Just before it gets to the secondary filter) along the top of the block to the Injection Filter.

Will these lines that are running along the top of the block keep the oil hot? (After the engine warms up of course) If the vegetable oil gets to the top of the block at coolant temperature, about what temperature do you think it will be when it gets to the injection pump?

Thanks in advance.

wvo

[RT]

Here is how I am going to do it: I don't have a mechanical lift pump on a 93TD and the factory electric lift pump is a weak one to start with. I will be installing a second electric lift pump at the WVO tank to push the WVO forward. Plan on using either a Holley Blue pump or a Purolater universal. Going to use a large heated WVO filter, then to the 6port valve then an electic fuel heater to boost the WVO temp thn to the primary filter and finally the IP. I plan on running a coolant heated WVO fuel system with a return line back to the tank. I don't like the idea of looping the return back to the IP. The electric heater will provide the boost in WVO temp and the return of heat WVO to the tank will heat the tank that much quicker. All evidence points to having the WVO hot, at least 160* but 180* would be better to keep the injectors from coking and promote the cleanest burn possible. I will also install a WVO temp gauge to monitor the WVO temp entering the IP. Adding the return line is easy enough. Regarding keeping the WVO hot between the lift pump, filters etc. you must either run coolant lines alongside in a HOH design or keep the lines as short as possible. Hope this helps, RT

[garysleeman]

RT
With pictures I think your project will be worthy of a feature article at TDP. I'm toying with the idea of burning WVO and the first obstacle is a second fuel tank. Does your truck have 2 fuel tanks? Was that even an option? I know earlier truck bodies had a 2 tank option. My truck has a 34 gallon tank on one side of the drive shaft and a big muffler on the other side. I'm not to keen on putting a second tank in the bed. Keep us posted.

[wvo]

Thank you RT. I am going to shop for a temperature sensor for the WVO and see what I've got. Do you recommend a particular version?

Garys, there is a lot of information about conversion on the web. greasel.com or greasecar.com are a good start. Running on vegetable oil has been going on since the beginning with diesels. Just be careful when you see "Kits" advertised. They may or may not have everything you need and the direction might not be right for your application. For example, the kit and instructions I bought for my suburban didn't say anything about a secondary fuel filter. Concequently, if I set it up according to the instructions in the kit, that filter would have been shared by the diesel and the vegetable oil (Not a good thing).

Good luck.

[gavio]

I can offer a few thoughts to consider based on my last couple years running veggie in my van. YMMV, of course, so take what fits and leave the rest behind......

I do not have mine set up to heat my entire second tank - just the area around my fuel pickup, in case my veggie should gel or something. I use a hose-on-hose to heat the oil - having the oil heated during the trip from the tank forward seems like plenty....

......but that's in part because I have an inline electric heater from Neoteric as the last stage in my conversion. It ensures that the oil is nice and toasty right before heading up to the IP. I felt this was important because in my van, all the conversion stuff is under the floor, since there is NO underhood area to work with, and I figured a constant supply of air rushing by at 70 MPH would have a major cooling effect :D

I took the factory lift pump completely out of the equation, so I'm just using an electric lift pump, purchased from NAPA. It seems to be up to the job, and with it, the fuel and oil are spared the long trip up to the front of the engine, and then back again, and then up to the front again - instead, it all just goes straight up the back of the block. This is one thing that's actually easier to set up on a van, since the back of the engine is much easier to get at than the front.

A temp gauge for the veggie oil sounds like a grand idea - but not one I've done yet. As a result, I don't know what temps my oil is at when it hits the IP, but Neoteric claims the heater will get it up to about 170 or so. Probably a bit optimistic in my case, since from there the oil still has to make it up to the top of the block, so I'd guess on a colder day with the engine still fairly cool, I probably lose 10 degrees of that. Depending on the oil you use, it appears from the research I've done on other forums that you have a fair amount of slack in the temp. Most folks whose opinions I recall agree that 160 is plenty and that 150 is probably sufficient.

What other forums, you ask? The most active and prolific is to be found at:biodiesel discussion forum (http://biodiesel.infopop.cc) Just follow the links to the SVO discussion forum - lots of folks there with lots of different experiences, kits and homegrown systems alike.

As for my system, after a year and a half, I'm seeing symptoms which indicate that my injectors probably need cleaning, but I do a fair amount of short trip driving, which is far less than optimum conditions for veggie oil usage (or diesel health in general) so I would expect it to take its toll that way.

More thoughts later when I think of 'em.

Good Luck!

[RT]

Interesting stuff Gavio! Are you running a return or looped system? Regarding the WVO temp gauge I was just going to use a regular engine oil temp setup. For the WVO tank I am going with a bed mounted tank. It will be raised up off the floor of the bed 8-10" on supports so I can still slide plywood, etc. under it. I am planning on the tank being approx. 60"X20"x8", 8" being the vertical measurement. I have a utility cap on my truck so the tank will be well protected. The reason for raising the tank is so I can keep the full use of the bed length. I am a contractor and need all the space I can get. The tank will cost $300-$350 custom made in aluminum, easily the most expensive part of the conversion. RT

[Keith Richards]

My hat goes off to you guys.This is real forward thinking,and I hope to be part of it someday when time and money will allow.I also want to smell it sometime,I heard it smells like fried food.

[gavio]

Hey, Keith, we'll be lookin' for ya when ya get to it! For the record, smells vary depending on the vehicle and the type of oil used - mine smells exactly like someone is barbequeing chicken :D

RT: I'm currently using a tank mounted inside my van - it was a temporary measure until I could get a custom tank made - 'course it's been in there for almost two years now......

The tank I need to get made to install under the van will look sort of like a cubist's rendition of a four-humped camel :eek: This is to fit around all the superstructure below as vans are unibody and space for a normal tank is nonexistent. Don't even know yet how much that tank will cost, but I'd be happy if it were only 350!

Oh, and I'm running a return system - I was scared off of looped systems because of hearing how sensitive these GM diesels are to air bubbles in the lines - I wanted it to stay self-purging. Also, when I started my conversion, I had only encountered a couple people who had even done 6.2s and I wanted to keep the factory side of my system pretty much intact (well.....apart from the Racor filter and electric lift pump and, and, and.....) so if I had problems early on with the SVO side of things, I could just switch back without significant drama.

More later......

[dieselbegreat]

I rode in my nephew's converted Mercedes he picked up for $600. He bought a kit which warms the fuel line with coolant and also the included tank as he drives, has a panel with electric switches and just keeps his eye on the coolant temp to let him know when he can go to SVO. When he switches over you can't tell a thing. Same power, idles fine, etc. The exhaust smells very clean though, not stinky like petro. Just make sure you switch over to petro before you shut down.