Low fuel mileage, ULSD & Timing

[FordGuy100]

Yes it is exactly backwards from Octane which as you mention resists compression ignition as the octane rating goes up, as cetane value increases so does a fuel's tendency to burn under compression only. So good gas has low cetane high octane and good diesel has low octane high cetane.

Okay, so you would then want to retard the timing. Simple math really:

47 (cetane rating for Bio) / 40 (cetane rating for diesel #2) = 1.175(17.5% retarted is what it is calling for).

So...

1.5 *ATDC x .175 = .2625. So you would have to retard timing roughly .3*, which would mean that using that method you would have to set your timing to 1.8* ATDC.

 

[Diesel JD]

Thanks maybe I'll just put it at 2 degrees and see what happens. I'm going to do a bunch of stuff to the truck over semester break coming up soon and timing should be one of them.

 

[FordGuy100]

Thanks maybe I'll just put it at 2 degrees and see what happens. I'm going to do a bunch of stuff to the truck over semester break coming up soon and timing should be one of them.

Yeah I hear ya man. This summer will be all work, and working on my truck. Tommorow and the next days are finals

Tommorow: Calc, Health (easy), advanced english (no way I'm getting a B damnit )

The next day: Chem, College English (whohoo I gotta learn all the pres. in order tommorw, plus what party they were ), and anatomy.

I'm ready for summer...especially the fricking weather, its in the low to mid 40's and raining right now, the moutains and passes are getting snow its time for some warm weather

 

[RLDSL]

Yeah I hear ya man. This summer will be all work, and working on my truck. Tommorow and the next days are finals

Tommorow: Calc, Health (easy), advanced english (no way I'm getting a B damnit )

The next day: Chem, College English (whohoo I gotta learn all the pres. in order tommorw, plus what party they were ), and anatomy.

I'm ready for summer...especially the fricking weather, its in the low to mid 40's and raining right now, the moutains and passes are getting snow its time for some warm weather

Low to mid 40s? Would you mind sending some of that over here? Was near 100 all week
Good luck on the finals

 

[FordGuy100]

Low to mid 40s? Would you mind sending some of that over here? Was near 100 all week
Good luck on the finals

Yeah, its been pretty dang bad. We've set some new low records for the high temp I think this week. Where is some of that global warming I hear of? I do my job, I drive around a polluting truck, I light brush fires (from when we logged), ect...

And thanks, I need all the help I can get. I seriously wouldnt doubt it if my parents disowned me after this semesters grades, wouldnt even fase me if they did (lets just say there expectations are extremly high for me)

 

[RLDSL]

Funny you should mention this. I just refreshed the fuel system on the Moosestang, and was thinking this exact thing when I set the timing. I put it at 10.5 BTDC using the pulse method. This is the upper range of the 2 degree + - tolerance of the factory spec of 8.5. I want to see if it helps with the other issue I will post about in a bit.

So Mel.... Any results yet? I'm chomping at the bit here. at least let us know what the butt-o-meter is telling you

 

[FordGuy100]

Hey, I heard that WMO has a lower cetane rating that diesel, in that case, should you retard or advance the timing?

 

[tradergem]

How would the higher viscosity of WMO, SVO, WVO, and biodiesel effect the timing? Usually flamable liquids that have a higher viscosity also have a higher flash point. The guys running vegi-conversion pre-heat the WVO/SVO not only so it will flow through the fuel system, but also so it will vaporize better when injected, and ignite more easily.
Jim

 

[RLDSL]

Funny you should mention this. I just refreshed the fuel system on the Moosestang, and was thinking this exact thing when I set the timing. I put it at 10.5 BTDC using the pulse method. This is the upper range of the 2 degree + - tolerance of the factory spec of 8.5. I want to see if it helps with the other issue I will post about in a bit.

Well Mel, It's been about a month . What kind of results did the timing change bring? The suspense is killing me
I'm ready to go break out the Ferret and get to twisting that pump

 

[f350flatbed]

WMO may have a lower cetane value (don't know if that is true), but it does have longer chain hydrocarbons that give it the higher btu rating. So it should push the timing further retarded. They picked cetane as the molecule for standardization but fuel is a big mix of different chain-length hydrocarbons. That's why some oils are better for using in making biodiesel, they have a greater content of molecules that can be split into long chain hydrocarbons. I think I remember seeing a chart showing that palm oil is really the best stuff to use but it's harder to come by here.

Paul B

 

[waynebo]

O.K the loss of lubricity due to the removal of sulfur is easily fixed but the reports of lost fuel economy are real and is it not the loss of sulfur that is the cause, as sulfur does burn very well indeed,light a match and you will see..so i would assume with thought out logic that the loss of fuel economy is a direct result of the loss of sulfur in the fuel,,jmho wayne

 

[david85]

I've been mulling over a lot of this myself for a while. I could't tell you where the timing on my engine is if my life depended on it, but through patience I was able to adjust the static as well as dynamic timing to get it where it is now. Smoke is completely gone unless I tromp on it and I can still pull pretty hard before I see even a slight haze.

Basically I timed the engine based on how much smoke I could see in the side mirror. Might sound strange, but I ended up retarding the timing slightly to get it where it is right now. But again, I have not idea exactly where it is.

 

[Diesel JD]

Its probably a little retarded there but you're very close if it runs good and gives you good fuel economy.

 

[david85]

My thoughts exactly. Thinking of poping up the dynamic timing just a touch and see what happens.

 

[Agnem]

Unfortunately, I don't have any scientific results to post. Seems to run better, but that just could be the new components. I don't have a way to do my milage figures since I don't measure the fuel I put in.