La Tortuga VO Build

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La Tortuga (1hd-t) VO Build

Veggie conversion

So I am reading and reading and reading about WVO conversions in Diesel engines.

I would like to say that I agree with Galt on holding my engine at a higher value than fuel savings, and I am not greedy. But I do want to be able to get the most out of this system, both by understanding it's limits and discovering the boundaries of acceptable risk.

Vehicle to be converted:
91 HDJ81 VX ltd
currently 230,000 km
Stock heated fuel filter (questions about this below)
Added:
Webasto (that can get my coolant up to operating temperature before I even start the engine)
Block heater
Oil Pan heater

My proposed set-up:
Two tank system: 24 Gallon Man-A-Fre aux fuel tank

HEXs: Hotfox coolant heated pick-up, VegMax2 coolant heated VO fuel filter, VegTherm (inline 12v heater). I was told with these components I wouldn't need a FPHE as well.

I'm using two 3 way valves. One for supply, one for return. They will be wired into a three way switch; positions: diesel for start (drawing from, returning to diesel tank), VO (drawing from, returning to VO tank) and purge (drawing from diesel, returning to VO tank)

I want to do the temperature gauge mod, so I have a better idea of my engine's temp, as well as having a second water temp gauge for my HEX coolant, and an oil temp gauge for my heated veg oil fuel (dual gauges are cool but outrageously expensive!!)

I'm hoping to have a secondary fuel gauge in my overhead console and wiring it as well as my OEM gauge to my switch so that my dash will be reading for whichever tank is active and the overhead console will read for whichever tank is inactive.

I am also trying to design two valves in my HEX coolant lines; I'm thinking cable controlled heater core valves that would let me shut off heat to my Hotfox and VegMax2 so that I can run diesel out of my second tank without burning it (lowering its lubrocity too much).

So now for the questions about my system:

Aux Tank:
Whereas the 1HD-T has the fuel pump downstream of the stock Fuel Filter, are there any ancillary fuel/lift pumps needed to pull out of a aux veg oil tank at the far end of the vehicle? My MAF 24 gallon aux tank came with a small electric pump, has anyone tried this option? Or, if a secondary pump is needed, nearer to the aux tank what would people recommend?
And as I addressed in another thread; trying to engineer a way to allow my aux fuel tank to be more flexible with the fuel type put in it, by controlling the heat to it's HEXs.
To understand more about this, I need to understand the dangers of having say my aux tank 1/4 full of clean dry (let's say 100%) VO, and needing to fill it the rest of the way with diesel.
Would I need 1/4 of the heat, to help with the VO viscosity and to prevent the loss of the Dino lubrocity? Or will the mixing diesel in thin out the VO enough?
What are the various properties of the blend spectrum?

Routing Coolant/HEX:
Keeping in mind that the webasto heats the coolant enroute from the engine to the heater core, I was thinking to T into the coolant line both before and after the heater core with adjustable valves. The T before the heater core will go into the VM2, out and to Hotfox. So the routing would look something like Engine>Webasto>VM2>Hotfox>return to far side of heater core. This creates the hot coolant/fuel counter flow.
I realize that most systems would have the heat exchangers in parallel, not series, but from the some of the advice I’ve received I should be able to rely on the 12V VegTherm heater for the final heating before the IP. yay or nay?

Routing Supply Lines/Filters:
Been thinking about Filters, clogging and purge times; Basically, been thinking that I run the diesel through it’s stock filter, and then into the supply valve, and I run the veggie through the VM2 then into the supply valve. This seems to be what Mr.MoMo is looking to do to reduce his purge times. Has he done this? Does this seem reasonable to anyone? Does anyone run veg through a coolant heated fuel filter then through their stock fuel filter? Cleaner oil? Clogging two filters at a time?

VegTherm Placement: put it inline between the switching valve and the injection pump/injection lines or in the veg supply line between the VM2 and the supply valve? Originally the first option would have required wiring the 12v heater to only power on through its temp sensor when the fuel selector was toggled the Veg (Aux Tank). Now that I’m looking at building my aux fuel system for variable heat settings depending on whether there is veg or diesel in the aux tank, I believe I’m going to need a separate switch to power the temp sensor, so that I can turn off the 12V heater if I’m pulling diesel out of the aux tank.

Installation Plan

First, need to address the coolant/heating issue:
Re-weight Fan Clutch viscous fluid (my fan seems to spin full out all the time, this cools my engine off drastically in the winter)
Do the temp gauge mod
install 2 temp gauges: Water temp, and Oil temp; water temp in line after the webasto, Oil temp in fuel supply line at 12v VegTherm.

Brackets for Valves, Fuel Filter (and FPHE if need be)
Run HoH lines
Remove Restrictor for Dual Filler Neck
Install MAF tank

Gosh, after all the proposal and questions the installation plan makes it look so simple! HAH!
 
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John, this is my original communication with Edward Beggs and Torie Carlson of Plantdrive.ca

"On Tue, May 7, 2013 at 5:55 PM, Dana Kittilsen <dana.kittilsen@gmail.com> wrote:
Thanks for all the manuals; I feel much more confident and in my understanding on the components of the system now.

Just one question: I have people who are running veggie oil, and have been for some time, telling me I will need a FlatPlateHeatExchanger--im assuming they believe I will need it on top of the hot fox, VM2 and Vegtherm, as that is the system I have described--so i have to ask, since a FPHE is not included in the kits that you sell: do you feel this system also needs a FPHE?
Cheers,
Dana

Here is the response from Torie, who had one, in Alberta Winters....

"No. It was hot enough. I had my VT on a switch and would shut it off when warm. It is a short vehicle. If he insulates the lines I don't see the necessity. " "

Just to clarify: I'm not opposed to the FPHE in my system; I put lots of stock in your experience, John. But also in these fellows at Plantdrive.
 
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Promises are cheap, engine rebuilds are not.
Plantdrive does not live or work in cold Northern Alberta, their experience base is USofA and southern Canada. Plantdrive is very reluctant to share the knowledge of the cases where vegitherms burn the VO and clog up with carbon that gets into the system and kills IPs if there is no filter between the VT and IP. Be sure you get a written guarantee that Plantdrive will fix your engine when the VT causes it to fail.
I don't sell VO fuel systems, I troubleshoot them; I have no vested interest in any company's products.
Monitor the temperature at one of the injectors. Whenever the VO is below 50°C engine deposits are forming.
 
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Promises are cheap, engine rebuilds are not. Plantdrive is very reluctant to share the knowledge of the cases where vegitherms burn the VO and clog up with carbon that gets into the system and kills IPs if there is no filter between the VT and IP. Be sure you get a written guarantee that Plantdrive will fix your engine when the VT causes it to fail.

Monitor the temperature at one of the injectors. Whenever the VO is below 50°C engine deposits are forming.
So:
The thing to do with the VegTherm, in your opinion, would be put a filter between the VT and the IP, with a temp probe on the injectors.
But you would more highly recommend:
Remove the VT completely, and replace with a FPHE--which receives the hottest coolant before anything else-- obviously still have the temp probe at the injectors.

If I am understanding this correctly something like an inline electric heater can burn the veg oil, whereas the coolant heating can not burn the veg oil, however you have to make sure you get the hottest coolant at the the fuel closest to the injection pump and lines.
 
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So:
The thing to do with the VegTherm, in your opinion, would be put a filter between the VT and the IP, with a temp probe on the injectors.
But you would more highly recommend:
Remove the VT completely, and replace with a FPHE--which receives the hottest coolant before anything else-- obviously still have the temp probe at the injectors.

If I am understanding this correctly something like an inline electric heater can burn the veg oil, whereas the coolant heating can not burn the veg oil, however you have to make sure you get the hottest coolant at the the fuel closest to the injection pump and lines.
If you want to use a vegtherm, use it to add heat to the coolant before it enters the FPHE. In process engineering design one adds the heat to the material with the greatest thermal conductivity and greatest thermal capacity.

In any design, all of the alternative fuel modifications/additions should be installed before the OEM fuel filter. The OEM filter is there to protect the very expensive IP and injectors, and nothing should be added between them. Trust Toyota, they know how to build reliable diesels.

You operate in the same hard cold unforgiving climate I do, reliability is why I drive a Landcruiser, I'm not going to compromise that reliability with an alt fuel design to save a few bucks. When evaluating advice always know where they're operating. Most of the Lower48 is rather forgiving for VO systems, but anyplace it gets below 0°F requires specific attention to detail to maintain that Toyota LC reliability in any conditions.

For fuel hose use NAPA-Gates 'Barricade' hose, it's 'hot-biodiesel proof'. The OEM hose between the filter and the IP must be replaced if VO base fuels are used. To hold the banjo fitting, pad the vice jaws with cardboard so as not to nick the gasket-mating surfaces of the banjo fitting. Cut diagonally across the crimp on the banjo fittings with a hack saw blade, being careful not to nick the ferrule on the end of the hose. Pull the crimp off with vice grips. Re-use the banjo fittings with Barricade hose secured with hose clamps.

Murphy's Law is true, and Murphy lives in the North. Anything that can go wrong, will go wrong, in the worst possible weather, at the most inopportune time, when wearing your 'Sunday best'.

Design accordingly.
 
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If you want to use a vegtherm, use it to add heat to the coolant before it enters the FPHE. In process engineering design one adds the heat to the material with the greatest thermal conductivity and greatest thermal capacity.
Very interesting.
Ensuring that the temp will be there for the fuel while removing the risk of burning the oil..
Quick question about your coolant temps.
The semis that I drive at work regularly see 180-210°f on the water temp gauge.
Before I get my own water temp gauge installed, just wondering: what kind of water temps we are seeing on our small diesels? Would it be comparable? And for 100% VO a temperature of ~180°f produces closest to diesel viscosity and characteristics?
 
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The temperature measurements I did on mine showed 180° -200°F coolant temp at the back of the block where the heater hose connects. That's where I added the T for the line to the FPHE. For a 2 tank system add another T for all the other fuel heaters in a series loop. I added the return line T where the return from the heater connects. 3/4PEX brass Ts are a good match with the 5/8 heater hose.

The optimum temperature for 100% VO fuel is 170° to 180°F.
 
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The temperature measurements I did on mine showed 180° -200°F coolant temp at the back of the block where the heater hose connects. That's where I added the T for the line to the FPHE. For a 2 tank system add another T for all the other fuel heaters in a series loop. I added the return line T where the return from the heater connects. 3/4PEX brass Ts are a good match with the 5/8 heater hose.

The optimum temperature for 100% VO fuel is 170° to 180°F.
The placement of the return Ts you described is exactly what I was thinking, however I will still place the supply line Ts after the webasto, which is shortly down the line from what you did.
So now, two supply Ts, first T to the FPHE (with the VegTherm in it) second T to the VM2 and Hotfox in series.

Quick thought, so that my coolants lines aren't just a series of Ts;
Seems that others are running the hottest coolant into their FPHEs with no problems; what about putting the hottest coolant from the engine (right after the webasto) into FPHE first, out through the VegTherm and 'rearward' to the VM2 & Hotfox?
Series keeps the T's to a minimum, also still allows all the HEXs to be controlled by the adjustable valves I want to install.
And if the series set-up is too much heat loss for effective heat exchange in the VM2 and Hotfox then adding the VegTherm should provide the rest of the heat needed, no? I could put the VT on a switch that is turned off when the HEX coolant valves are shut.
 
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There is a good reason to put the FPHE on it's own coolant loop, not in series with the other heating devices. Try sucking water through a 2ft hose vs a 20 ft hose and see if you notice any difference in resistance to flow.
 
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After another round at the drawing board: webasto to T to adjustable valve to Y one way to the FPHE, the other to the VM2 & HotFox.
Return from VM&HF comes back and Ys into another adjustable valve and then Ts back into the line on the other side of the heater core..
:bang:
Do your worst John
 

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And just to up the fun factor :popcorn:
Because of diminishing space in the engine bay (Webasto, supply/return valves and now the FPHE, I am thinking the best space for the VM2 is in the rear interior panel where the jack used to go.
 
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That diagram looks very workable to me; it's a good design. I like how the webasco can heat the engine bay VO system as well as the engine, and even the cab heater, slick! I don't see any problem with moving the VO filter back near the tank. For fuel and coolant lines that don't need to bend in a sharp radius PEX tube is hard to beat for cost and available fittings. Bundle the tubes with zip ties and cover with foam pipe insulation.

What's the blue and red thing on the diesel fuel line?

The heating system probably already has a valve that controls the flow through the heater core.
 
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Huzzah!!

There is a valve that controls coolant flow into the heater core. It is the stock cabin heater control. Currently it has to be wide open or the Webasto wont heat the cabin or the engine. It gave me the idea for the adjustable valves controlled from the cabin.

The blue lines represent filter; red, heated filter. The diesel passes through an electric heated fuel filter as part of the stock fuel set-up.
Earlier diagrams were more thoroughly labeled. I'll make sure everything is fully labeled in the final diagram.
 
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Huzzah!!

There is a valve that controls coolant flow into the heater core. It is the stock cabin heater control. Currently it has to be wide open or the Webasto wont heat the cabin or the engine. It gave me the idea for the adjustable valves controlled from the cabin.

The blue lines represent filter; red, heated filter. The diesel passes through an electric heated fuel filter as part of the stock fuel set-up.
Earlier diagrams were more thoroughly labeled. I'll make sure everything is fully labeled in the final diagram.
If the only thing immediately ahead of the IP is anything but a filter you're asking for trouble. If it were my truck I would do all the mixing/switching before that OEM heated filter. Yes, you will use a few cents more purge fuel, to save thousands on IP and Injector repairs. Toyota puts the filter there for a good reason.


It's sorta like why wearing a condom on your tongue isn't as effective for birth control

A filter on the VO line is effective, but polymerization can occur anywhere in a UVO system, even after the filter, so it doesn't really protect the IP from the common problem with UVO fuel.
 
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Not only is it easy enough to put the stock fuel filter down-stream of the switching valves in my little drawings, but, looking at mounting spaces in the engine bay, it makes more sense to do this.
Purge times be damned, I let it idle for the turbo to cool down already anyway.
I like the idea of using a turbo timer to aid in purge timing.
 
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One other detail to consider. A common cause of problems with VO fuel systems is air in the fuel, particularly as systems age with temperature extremes. Air molecules are much smaller than liquid molecules, especially hydrocarbons. Air can get sucked in through a crack that liquid couldn't get pushed out of. That's why Toyota minimizes the number of fuel system components and connections on the suction side of the fuel feed pump. Try to do the same with any fuel system design. Where possible minimize the number of fuel components and connections under suction.

You're right about turbo cool down and fuel purge times working together. Once you get the system running, then a short piece of clear fuel line on the return would let you see when the VO is flushed out. If the VO fuel isn't dark enough then add some ATF to the UVO in the tank. Run it at 1K, 2K and 3K RPM to see if purge times change much with speed. A few simple calcs will tell you how many klicks before stopping to switch over plus the 1 - 2 minutes of turbo cool down.
 
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