Monday, February 18, 2008

single tank conversion

under my hood these days

So finally, with the help of Billy Jacobs, we're running on vegetable oil. Ol' Esperanza is ready to go. I ended up buying a kit from Craig Reece that included the Plantdrive vegtherm, an electrical boost heater.

the vegtherm electric boost heater

The kit also included a "TurboFyner" from Ramco, which is the coolant-heated fuel filter.

the turbo-fyner coolant heated filter

A minus on the Craig Reece kit, is that you have to get most of the install parts yourself. Since I had to source and buy all the hoses, fittings, etc. anyway, of course I ended up modifying the install to some extent. I put in some temperature gauges, (one after the heated filter, one after the electrical boost heater). I also changed the order of part installation to one that made more sense to me, and added another clear filter.

The instructions that came with the kit were a bit spotty. Really thorough in parts, but misleading in others. NO DIAGRAMS!! (what!?!?). My dirty schematic looks like this.

under my hood these days

So, anyway, it's done, and I even mounted the temperature gauges above the steering column so that they would look nice.

pretty, but as it turns out, useless gauges

Also - it seems it doesn't get as hot as quickly as I expected. Sad. So there are some changes planned that I might make: reduce the amount of fuel hose in the engine compartment. change the alternator to something rated for higher loads. Also, gauges that monitor lower temperatures.

UPDATE - a week later, and we've already had a part go out. I hadn't had time to replace the delivery hose (from tank to engine compartment) with the higher diameter viton to compensate for the higher viscosity of the veggie oil. This created a higher pulling pressure on the components and lines before the fuel pump. So the manual fuel pump started leaking air, and jess got stranded one morning just before the Richmond bridge. This wasn't an expensive repair, and it was one that many folks recommend doing even if your hand pump isn't broken (because a later model pump is much easier to use). It also was actually kind of predictable (in hind sight, of course), so no fault, no (major) harm. I'm still learning stuff. Also, I'm going to have to check for more leaks in a month or so...


Blogger Maia Dobson said...

This comment has been removed by a blog administrator.

4:00 AM  
Anonymous Anonymous said...

Any chance you can post more detailed pics of you install? I just bought a PlantDrive single tank kit and it would be a huge help with install!

7:26 PM  
Blogger aaron said...

hey anonymous, you know, getting a good photo of the system is actually pretty hard, what with the installation being 3d and obscured by a lot of stuff... The wide angle view shows a lot of unrelated and confusing stuff, and close-ups don't tell you how things fit in the system. I think the diagram I posted (click on the picture) makes a lot more sense than any photos, and I tried to get photos. Especially after I insulated the system, all the connections are covered up. So, sorry, I tried to post more pics, but they're confusing, and I didn't have time to do a full process documentation.

As a general update on the car, because I haven't posted anything on it in years:

After a while running the system and not getting the temps I wanted to, I added another heat exchanger - a flat plate heat exchanger before the vegmax. After that, I usually had temps above 140 on the highway, and always above that in street traffic.

We've run the car ~60k on vegoil at this point, and so far I've had one point of failure in the system that was surely linked to the install. Coolant leak! I had one of the plastic coolant line Ts get brittle and break. It's in a spot where I have to push on it when I change the oil filter, so that may have been what caused it to start leaking. After it leaked a bit, one really hot day (when the coolant volume may have gotten low) it had a catastrophic failure. Luckily no extra damage caused, I spotted the temp rise right away and was able to replumb the coolant on the fly and get where I was going. I limped along for a while with intermittent coolant leaks until I could replumb everything better, which caused some embarrassing incidents, but ok on the whole.

Perhaps related to the system, I had the original water pump go out, then replaced it with a used pump which went out about 5 years later. Something to do with the install? Who knows?

Another perhaps related to the system - the air vent that lets air into the gas tank got plugged. Because of veg oil? Because of age? Who knows. A 32 year old car will have problems. Anyway, this caused a vacuum in the tank, and the tank collapsed! Going down the road one day, it sounded like something hit the bottom of the car really hard. Boom! This one is something of my fault. There was a tell-tale sign - when I'd open the fuel cap, it would make a sucking noise. We also had frequent air in the fuel lines (caused by negative pressure in the fuel system, I see now). I asked my mechanic about it. He said it was normal for these old cars and wouldn't cause any harm. Wrong! He suggested changing the cap, which I did, thinking maybe the cap had a vent in it that I couldn't see. Wrong! If I had bothered to look at some schematics, I might have noticed the vent and checked it out. Oh well! On the plus side, I guess my fuel pumps are pretty strong.

Anyway, my tank is now a 12 gallon tank, when it used to be a 20 gallon tank. Sigh. I'm gonna get that fixed one of these days.

11:44 PM  

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