To Bio or not to Bio....that is the question.

[limatangobravo]

To my fellow diesel owners, does anyone happen to know if Bio-diesel can be poured "straight over the rocks" for early diesels? I have a 24 valve Cummins (1999) and a 7.3L (1995), driving in other states offering this fuel at a lower cost is great. I did not take the plunge with my reluctance of reliability or damage that may happen if I used the synthetic fuel.
I realize newer diesels have the correct programming, DPF's etc to utilize Bio-diesel. Anyone who has experience using this please let me know your thoughts.

 

[luthj]

First, does the diesel in question meet the relevant ASTM biodiesel certification? (I believe it is ASTM D6751?) If it does you have little to be concerned with assuming you are running a diesel that is pre DPF. Home made or non-spec fuels can have some very odd properties, and often have low cetane value (in addition to dissolved waxes and similar contaminates).

Believe it or not engines with DPF are the most at risk from bio fuels. This is because the bio has a higher boiling point. When the engine uses post combustion injection to raise the exhaust temps (to regen the DPF) some of the bio can get washed into the crankcase. This can lead to oil contamination and dilution.

Also bio fuels are more prone to creating deposits in the fuel system than regular diesel. This is not a serious concern non common rail engines as these engines use much lower fuel pressures, and have larger tolerances in the injectors and pumps. Common rail engines use higher pressures and have tighter mechanical tolerances so bio fuels pose more of a risk for them.

All that being said, I would check with your engines manufacturer for their recommended maximum bio percentage blend. Most manufactures specify a shorter OCI interval for engines running more than 20% bio blends.

 

[Bikersmurf]

Some of the fuel lines and O-rings around the fuel bowl aren't fond of BIO on a 7.3. My 97 seems very happy on it... although B5 hardly seems worth it.

Abitibi has run Bio and WVO in his 7.3 with good results.

Cummins isn't in my area.

 

[luthj]

Good point, some rubber types don't like bio fuels. Thankfully viton orings arent terribly expensive.

 

[IdaSHO]

O-rings are cheap

Injectors are not


Ill feed my 7.3 a bio blend if thats all thats at the pump, but it will never see WVO.

 

[limatangobravo]

O-rings are cheap

Injectors are not


Ill feed my 7.3 a bio blend if thats all thats at the pump, but it will never see WVO.

No doubt, I have already replaced injectors. Not much fun on a Van, I have deleted the fuel bowl so no issues there.
Thank you for the info gents. Looks like I have my homework set in front of me.

 

[dcguillory]

My van ran on B100 for 2 years with no adverse affects. I run B20 now because its cheaper then regular diesel around here. No problems. No extra filter changes. I have had to rebuild the fuel bowl once in my ownership (5years)

 

[limatangobravo]

My rig has two tanks, I have thought about running one with BIO and the other with OLD NO.2. What is in the BIO that creates the deterioration of the rubber seals?

 

[dcguillory]

The B rating just means how much of it is not diesel. So even though there has to always be at least around 1% diesel for normal engines, anything B99 and above is just called B100. Anything with veggie oil has seen reports of problems with O-rings and such. The lack of reports greatly out weighs the complaints, but you don't wanna be the one guy either. The only reason I used bio was because it was cheaper and the van was already running it for years when I got it. The place I got my van from was a tour company that also made, and had a public pump for, B100. I don't have some miss-placed sense of saving the earth. Just saving money.