Running commercial B20 biodiesel

[philip]

Philip,
I (and I'm sure others) would like to see your test repeated without the timing retard. 4 degrees is a lot, evidenced by your hard starting, low power and extra smoke. B20 shouldn't endanger pistons at normal or even slightly advanced timing with good injection patterns and mindful throttle application, even on severe grades.

How about it, when you get a chance, back to back, timing difference only evaluation?

Did you read earlier in this thread my reason for retarding it in the first place? Past use of B20 biodiesel has produced same symtoms but because the last run was during warm summer months, much less.

Have you read my experience with injectors on this truck?

Being "mindful" of throttle application at altitude is what the altitude compensator (I wrote a thread on that too) does ... FOR you ... when adjusted correctly. The one on my truck is in proper working order.

What "shouldn't" happen vs experience ... I'm dealing in the latter.

[exsimguy1]

Philip,
Yes, I read the earlier post about "cackle"(just reread posts and I did mix two different posts - Sorry) and the reason for retarding the timing. I would think 1-2 degrees would be plenty for the fuel difference. However, in cold weather, retarding would not be needed or desired to keep a "fire built". Most cold starts "advance" in anything that changes timing due to ambient temp, and run better while engaged.

Yes I have read your injector experience, and that is why I would assume a good spray pattern.

The altitude compensation control, when working, only limits the max amount of "rack" the pump will deliver to the injectors based crudely on atmospheric. If you were smoking excessively at altitude, you were still feeding more fuel than the air would support. Thus my comment on "mindful throttle application". Easing off of throttle would not slow you down, and might actually gain some speed.

[philip]

Tues morning. I returned injection timing to my previous preferred setting. Start up was better than yesterday with less misfire which cleared up shortly after the glows clicked OFF. Fuel gauge is on the edge of E mark.

Down the street we go ... cackling/knocking/pocking along more than yesterday. I brought along 2 gallons of D2 with the intention of running the tank level down low and if necessary, adding the Jerry jug. Not fond of walking for fuel.

I ended up at Pearsons Ford / Fuel Stop in San Diego. All they sell is B99.5 ... no B20 anymore. Hmmm. So at the fuel island I bought 5 gallons of Willie Nelson's B99 and 5 gallons of D2. The fuel desk required me to fill out a co-op form and sign off that I read and understood a two page warning about B99. WOW ... I never got a warning sheet like this from the Cudahy fuel stop!

Did all the paperwork, pumped the fuels, and headed for home. Truck ran fine. Tomorrow morning should be "interesting" on this roughly B40 mixture.

[exsimguy1]

Philip,
Thank you for the thoroughness in your experience/report.
My thoughts are probably similar to yours right now, what was with the last tank of fuel? Doesn't sound like B20 should have caused that much grief or difference in performance.
Please let us know what you may find out.

[philip]

Wednesday. No changes to engine settings or fuel from yesterday (B40+ mix). Temps last night 45*. About 4 gallons used from San Diego refueling.

Started the engine as usual. It started and ran pretty much the same as yesterday ... rough with misfiring and raw fuel smoke that settled down within 2 minutes. Raising the RPM in neutral brought on plenty of combustion knocking. Driving off, it's hard to imagine the knocking was POSSIBLY worse! 3rd gear at 17 mph is the start of hard "pocking" sound combusion noise. SHEESH! As before, when the temperature meter reached operating temperature, all combustion knocking died away.

So ... I've got the same symptoms from two different fuel samples (Los Angeles & San Diego). Both sources state their D2 is the ULSD formulation. Both are high volume stations. Cudahy blends their B20 on premisis while I had to blend my own at the pumps in San Diego (I deliberately made a stronger blend).

Prices at Pearsons (Feb 13)

[exsimguy1]

Philip,
On other forums, there are rumblings of higher than normal gel temps on #2 ULSD. The stoppages are visually akin to paraffin. Way back when, the methods used to remove sulphur also reduced paraffin content. It looks like this may have changed. I guess it's time to stick samples in the freezer again.

Suggestion - without any timing or fuel mix changes, maybe try some fuel additive, even if it's on the way to fill up next time. You may not be cold enough to gel, but between the B40 and (if it's true) extra paraffin, maybe the "less sophisticated" injection system of an SD cannot squirt efficiently (causing knocking).

Or - maybe the vapor point of the mix is boiling in the injectors, similar to when the injector gasket(s) don't allow for correct heat transfer to the head.

Just a few thoughts.

[philip]

Philip,
On other forums, there are rumblings of higher than normal gel temps on #2 ULSD. -SNIP- I guess it's time to stick samples in the freezer again.

On it. Tonight a half pint sample of Unocal USLD D2 is going in the freezer with a thermometer. I don't know to what degree this sample is "winterized" for this area. Color is very very pale yellow/green, almost clear.

(Later ...) I put a sample of Unocal D2 USLD in the freezer with a thermometer stuck through a tin foil lid. At 25 degrees there is no clouding at all. My freezer maintains 3-5 degrees so ... I'll leave the sample in for the night.

Suggestion - without any timing or fuel mix changes, maybe try some fuel additive, even if it's on the way to fill up next time. You may not be cold enough to gel, but between the B40 and (if it's true) extra paraffin, maybe the "less sophisticated" injection system of an SD cannot squirt efficiently (causing knocking).

With the new injectors, I've always run Stanadyne's lubricant in the fuel. I have not included it with this BD test.

I have a bottle of PowerService handy. Using straight USLD D2, I've already found that PowerService mixed in at recommended levels -seems- to worsen cold engine combustion knocking. Mixed at 1oz per 3 gallons (much richer), this -seems- to reduce the phenomenon.

Or - maybe the vapor point of the mix is boiling in the injectors, similar to when the injector gasket(s) don't allow for correct heat transfer to the head. Just a few thoughts.

The phenomenon slowly abates as the engine achieves operating temperature regardless ... of fuel. It's all a matter of degree. Using D2, its only noticeable during warm-up. On B20 / B40 the knocking can be enough to echo loudly off parked cars until the engine gets warmed. Have to keep the revs down ... way down.

I messaged Customer Relations at ITL Spirit (Cudahy Truck Stop) about their B20. Here's the reply I got yesterday.

We only blend with No.2-D CARB Ultra Low Sulfur diesel. I am not aware of a No.1-D Ultra Low Sulfur diesel being available in So Cal. Our last test shows a cetane of 50 with a cloud point of 33F. Keep in mind that water freezes at 32F so if there is any existing water in your fuel tank there could be an affect on cloud point when you introduce B20 to your tank. Our Biodiesel is derived from Soy and we blend here at our facility.

Thanks for your inquiry.

Jeff

(NEXT morning)

The freezer thermometer shows 3 degrees and the ULSD D2 sample has been in there for 7 hrs. The fuel is thin and fluid. At first glance there is a very thin wrinkled surface on the fuel that does not quite cover the whole surface. Faint clouding evident. I moved the sample to the less cold section of the refrigerator to allow the sample to warm slowly. Later ... at 10-15 degrees, there are only small traces of whatever was occuring on the fuel surface.

[philip]

Ambient temps last night 46 degrees. I didn't fire up the truck today until mid afternoon ... ambient 71 degrees. Still on the San Diego tank of B40+.

Truck fired right up and misfired three times in the first 10 seconds ... that's it! BIG improvement. After a short warm-up, I headed out. Combustion knock was almost typical of straight D2 so ... no need to baby things along until reaching operating temperature. Hmmm. All combustion knock ceased between the Cold mark and the operating range.

The only observable change was the relatively warm air of today.

[philip]

Saturday morning. A mild Santana Wind condition set in yesterday which pushed up ambient temperatures. Last night's low was 67 degrees. I'm closing in on the EMTPY mark of the San Diego B40+ fuel.

I fired up the truck about noon. Ambient temp 81 degrees. It fired right off without a single misfire. Gave it about a minute warm-up and took off. Moderate combustion knocking evident (just like yesterday) but nothing dangerous. Knocking persisted until the coolant temperature was just inside the operating range.

I'm looking forward to refueling with good quality D2 soon!

[philip]

I'm looking forward to refueling with good quality D2 soon!

Second morning on straight D2 (ULSD). Overnight temps 43*F. 53*F at start-up.

Engine started right up, no misfire. After 1 minute, heading down the street with the usual combustion knock when the revs are up but not dangerous. All combustion knocking ceased with temperature meter between Cold mark and the operating range.

I can't say that power was any different with B20 or B40+ mixtures. For this engine, B20 or stronger is a summer fuel (overnight temps no lower than 70*F).

These engines with their 22:1 compression, no electronic safeguards, and high base timing not does not like TOO much fuel cetane. Remember the response I got from ITL fuel stop about their B20 ... cetane 50.

But soy Bxx smells nice. Next experiement will be with B100 made from used fryer oil reclaimed from Italian and Asian restaurants instead of virgin soy. Should be interesting. But I'll wait for warmer weather.