You and your Diesel Fuel

Like always I’m learning something new when Scott Daniel takes a moment to post to the Diesel Vanagon list.  Thanks!

“I am adamant that a fuel additive must be used in pump diesel fuel. The kind that ‘improves combustion, reduces smoke, improves power.’”

So here is what I’m hearing.  Anyone with a VW diesel should be adding a fuel additive which will improve the combustion quality of the diesel fuel they are burning.  Over long usage, the fuel additive will improve engine performance, preserve the fuel tank and lines, and decrease wear and tear on engine internals (the injectors, block and pistons).

So I’m searching and there are many different types of diesel fuel additives.  Some of them are designed to lower the gel point of the fuel and from what I can tell these usually have a fair amount of ethanol in them. Some are simply lubrication. In either case I don’t believe that this is what Scott is referring to however; rather I think he’s indicating a Cetane improvement mix.  Wikipedia has a pretty good description of what this is, but to summarize Cetane is a measure of diesel fuel’s ignition delay.  The higher the cetane value is the shorter the ignition delay.  And from further reading cetane seems similar to octane rating which many of us are already familiar with.  Here’s some standard values, the next time I fill up (probably with diesel #2) I’ll see if the cetane value is on the placard.

Regular diesel	48
Premium diesel	55
Biodiesel (B100)	55
Biodiesel blend (B20)	50
Synthetic diesel	55

http://alternativefuels.about.com/od/researchdevelopment/a/cetane.htm

What really got me interested in this value is the following statement from the link above “running a diesel engine on fuel with a lower than recommended cetane number can result in rough operation (noise and vibration), low power output, excessive deposits and wear, and hard starting.”  So having a higher cetane value than is recommended for you engine does no good, at least for combustion, but having fuel with a lower cetane value can actually harm engine performance as well as reduce its life. Sounds a lot like what happened to Zeno’s old 1.6l.

So next I went looking specifically for a cetane additive that might meet these qualifications more or less intent on finding how much I might be able to improve the average cetane ratings of the above fuel formulations.  AMSOIL Cetane Boost Additive is the brand that I’m working from at the moment specifically because they not only talk about the benefits of the additive (which is well documented elsewhere), but also because this manufacture quantifies the improvement in cetane value per fuel/additive mix ratio.  Somewhere on average between 3 and 7 points depending on how much you add.

If the cetane value for the fuel you pump is on the fuel pump placard you should be able to calculate your optimum additive ratio based on that known value and the cetane value the engine manufacture recommends for your engine.  If, for example, you’re pumping “regular diesel” with a cetane value of 48 and your engine manufacture recommends that you run fuels with a cetane value of 51 then if you used the additive listed above you’d only add one fluid ounce per 10 gallons (1oz/10gal) of fuel pumped.  Say, however, your engine is rated for a cetane value of 55 you’d effectively have to double the amount of additive mixed with the fuel (1oz/5gal) to get you to the optimum cetane operating rating.  You see how this knowledge should affect your supply of additive?

Now all I need to know is the cetane value that Volkswagen recommended for my new 1.9l NA engine.  Better yet, what Scott recommends.  The former is probably pretty close to the latter.  Very cool information, this is going in Zeno.  Also recommendations of specific brands and mixes are welcome.

Project Re-master

So, lacking a crystal ball or knowledge of the time and place of Zeno’s impending death, I’ve made a decision to replace the power plant on Zeno at some cost and some delay to the whole project. Bummer, but driving the van stripped of its interior has exposed a number of “custom” bits of work that have increased that little nagging feeling at the back of my skull while tootling down the road. What’s that sound? Is that a new noise? Why isn’t that light working? I’ve not been getting the farfergnugen I so crave mostly because I’ve been calculating the distance from one tow to the next.

 

Time for some math, so I’ve weighed the potential of a major failure because of some weirdness of cobbled-together attempt to claim a little more horse power from the 1.6L NA that’s in there, the cost of creating a custom exhaust, and that of welding up an air intake that doesn’t suck road dirt and expelled exhaust against the cost of a new project to replace the engine with something significantly more simplified (no turbo), considerably newer, less hacked together, and professionally managed. This is obviously an opportunity cost in the project, but one that I’m actually somewhat happy to be dealing with at the moment. Here’s why.

Guru Scott

By way of the Diesel Vanagon Mailing List I’ve had the pleasure of meeting Scott Daniel of TurboVans.com who is unquestionably a sweet fella. Kind of like reading the side of a bottle of Dr. Bonner’s Magic All-One soap, but in a really good way. I came away from his site with two key impressions of the guy:

1. Scott really likes working with people
2. Scott really likes working on Volkswagen Vanagons

And I mean really likes working on these vehicles. He’s excited about a box on wheels that’s nearly 30 years old. And while I couldn’t agree more, they are great automobiles with more utility and sense built in than a collectors garage will ever see, his enthusiasm about them is very compelling.

Tess and I spent the weekend driving Zeno down to south western Oregon, almost California, from central Washington. When we left it was cold and sans internals Zeno was a chilly ride. By Portland things had warmed up significantly and I had to pull over at a rest stop and peel off my extra layers. I was already sore from running the day before and there were still countless significant grades I’d have to coaxes Zeno to summit ahead of me. By the time we arrived at Scott’s shop I was ready to turn in for a very long while.

Ok, there are a lot of busses here. That’s probably a good sign. Then the man shows up at the garage and I’ve now forgotten about the kink in my right shoulder that threatens to be the weak point in my body upon which the rest of me might implode. We’re talking about a burn victim van he’s rebuilding with a Subaru engine and I’m having trouble remembering that both of my thighs locked up hours ago and have contacted the Union to threaten a strike. He and I are walking around his shop looking into all the cool little bits of Volkswagen stuff and the endless projects he’s tinkering with and my smile is growing ear to ear. Tess has to whisper to me that she’s hungry and we need to find a hotel before I’m ready to depart. It was like visiting a Guru who happened to have figured out how to live a happy life.

Left to Right

More Vans

Even More

Left to AW

So we got a chance to exchange some information, talk about some of the problems I’ve been having with Zeno, and gave Scott plenty to do and think about over the next couple of weeks. That drive was completely worth the effort and I’m really looking forward to seeing more of his work as time goes on.

The Block

If I get my way, I’ll take the train or a bus back down to Phoenix, OR and work my way to the garage so that I can spend more time mixing it up with the Master.