95' Junker Drag Truck

madmikeismad said:
How low below the sump? Add a quart?
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Lost a crank before figuring out the prob. Thought it a bearing issue at first. Adding a qt would still be borderline at best. Made larger alum pan and no more probs yet. Restricting flow to rockers like hi rpm gassers do is something I plan to look into.
 
akadiesel said:
Lost a crank before figuring out the prob. Thought it a bearing issue at first. Adding a qt would still be borderline at best. Made larger alum pan and no more probs yet. Restricting flow to rockers like hi rpm gassers do is something I plan to look into.
Click to expand...

I was trying to think of fixes without making a new pan LOL
 
Good points on the oil sump going dry at high rpm. There are two main methods many of the top engine builders are using to provide adequate oil pressure on these cummins motors:

#1 Stock updated 12v/standard 24v pump with restricting plugs in the rocker feed ports drilled to .060" and shimmed pressure regulator.

#2 Slightly modified 8.3 Cummins oil pump with extra lube (over filled oil pan) and shimmed pressure regulator to achieve adequate pressure.

Option #1 will likely have less HP robbing drag on the motor since it won't be pumping as much excess oil. However, I'd prefer to extra capacity in case this motor ever runs (3) journal bearing style turbos. I'd also prefer to maintain top end lube because the rockers tend to run dry at times with stock setups.
 
a good Idea in most SBC builds has always been porting the oil drain backs to free up return flow... could help in this instance.
 
Big Blue24, I'd like to throw something at you since we talking oil and I don't know where would be the proper place to post it. You got lots of info and still an open mind. You do things that might intimidate others. You save a dollar everywhere you can and use a lot of our"country boy" methods as well as look at what gives or robs minor hp. Ok, what I'm after is the best temperature for diesel to be injected at. Cummins says 159 F is max recommended due to lubrication loss above that. We run up to 50% so far oil added in diesel, so lube issues solved. There is also a very noticeable increase in power with our mix and zero negatives. Now its time to raise the temp. Any input?? We been running it in ve, vp, p pumps, and crs for years. Lots elsewhere for burning oil but not in a performance point.


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I might be able to help out with that question. In a pure form the lubricity of diesel is not bad until you get to higher temps and then the film barrier can break down and that very tight tolerance that you need (2-4mic) becomes a friction point and thus wears parts out.

[Quick point about sulfonated diesel... It is good for maintaining that lubricity boundary in lower injection pressures (sub 25Kpsi), but in high pressure applications the molecular structure changes and it becomes a scrubbing agent, hence one of the reasons they have removed sulfur from diesel (other than environmental reasons)]

Diesel being and oil itself and adding oil to it can potentially increase its tolerance to film strength break down AND also provide extra power provided the molecule chains are equal to or larger than the diesel fuel itself. (short chain vs long chain molecule structure is like gas to diesel... one has more power)

To the point of adding heat to the fuel to make it burn better. If you increase the over all temperature of the fuel it flows better and has slightly more potential energy that cold diesel. The "thinner" diesel in theory should be able to flow slightly more volume though a fixed orifice over a period of time (injection time though injector tip holes), but it comes up to a point where you can only put so much volume through a hole in a fixed time no matter how thin it is. There will be a formula for calculating the maximum temp for the most amount of fuel to give the best result, but i honestly don't know it at the moment.


With all that technical garbin out of the way I can say this. If you find an oil that has more energy content per ml that standard diesel, and you can get it thin enough to act as diesel in its properties through an injection system, there is nothing saying you can't run that and get more fuel energy in the cylinder to burn.


This is simply explained in todays terms with UFA in Canada. They used to make a "farmer grade" fuel that offered 25% more power than standard diesel (according to adverts). Farmers would run it and notice more power, and more black smoke out the exhaust. Reason being the fuel was heavier chain molecules than standard diesel and thus had more energy per ml. The inverse is true with winter grade diesel up here in Canada. The lighter chain molecules have less wax in it and still flows at the -30C temps where standard diesel will gell up.
 
With that formula, that could be useful info. It isn't a question of if, but how to get the max energy from pure or mixed diesel. Where should this best be discussed in length?


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To be honest, the math involved with that goes much further. the heavier you make your Fuel source the more in cylinder temp you will need to ignite it. Look at how gas at a lighter fuel can burn by match, but diesel needs substantially more heat to light up. The temperature of the fuel will help with the auto ignition due to the added energy you gain from the cylinder compression to make ignition, but there would be lots of testing involved with that. Here is a link with the comparison properties of grade 2 diesel compared to gas and ethanol, and you can see how in depth it goes in a hurry.

IMHO, adding oil to your diesel may give benefits, but the biggest would be to your personal feelings to the product, and less of the product itself. The best way to get more power is to inject a large volume of fuel in a stroke through an appropriate sized hole to maintain injection pressure. There is lots of aftermarket support in these area's of getting more fuel in, versus making the fuel more potent in your question.

But i do applaud you for thinking beyond the box and looking for different and creative methods to get more bang in the cylinder.

http://cta.ornl.gov/bedb/biofuels/ethanol/Fuel_Property_Comparison_for_Ethanol-Gasoline-No2Diesel.xls
 
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