Diesel lubrication question!

[larrybuck]

Most of us know about how "straight" diesel now being sold is meant really for 2007, and later diesels.

I have an '85 Suburban w the 6.2. Here locally, I have several sources for Bio-diesel, so have not had any issues, but now am contemplating spending some extensive time towing in MT., WYO., the Dakotas, where out in the tullies, I may only find that "new" diesel.


A past neighbor of mine suggested that I buy some of the cheapest motor oil possible, and pour slight amounts directly into my fuel tank. He said that the worst thing that can happen is that the exhaust will be more smokey!


Would this be a viable solution, or is it a little crazy!

I have a 40 gallon tank. What would the proper ratio be? A few tablespoons?...more???


I'm serious as a heart attack. I like my rig, and want it to live. I can't afford anything newer anywhere in the near future!

I certainly would appreciate any useful input about this.


In conclusion, in addition to the states I've mentioned above, do any of those plus Nebraska, Minnesota, Iowa, Kansas, Colorado, Wisconsin;.... do any of these states use much salt on their winter roads instead of other chemicals to deal with ice?

Thank you for any help!!!

[UFO]

Motor oil is not a good lubricant for diesel injection pumps. In the Spicer study, it did not add any lubricity to the baseline fuel. The best is biodiesel, some commercial additives performed OK too. You could use two stroke oil, it's designed to lubricate and burn in a combustion chamber.

[oil pan 4]

I have almost the same year 6.2L based truck.
Just adding vegetable oil will make the fuel much more oillier.
I dispose of used motor oil by way of the fuel filler. The worst I have ever done was 6 quarts of used motor oil into the 25 gallon tank, every time I changed the oil.
One of my first mods was to can the stock fuel pumping and filtering system for one of my own design and it has worked well since 2006.

[Ryland]

I've read about people using bio-diesel in 2 stroke gas engines instead of regular two stroke oil to mix with the gas and having good luck with a 10 to 1 ratio and as thin as a 20 to 1 ratio, around here it's not uncommon to find a 50 to 1 ratio of diesel to bio-diesel (B2) at the pump at filling stations.


Yes Wisconsin and Minnesota salt their roads in the winter, if you have bare metal that you don't want to rust and plan to spend a bit of time in the area then paint it or better yet, paint it then apply self healing rubberized undercoating, you can get it in the gallon can or in the spray can.

[ConnClark]

Originally Posted by UFO

Motor oil is not a good lubricant for diesel injection pumps. In the Spicer study, it did not add any lubricity to the baseline fuel.

You might note that they tested USED motor oil with 5000 miles of used and not new motor oil. The reason why people remove the motor oil from their engines in the first place is it no longer is suitable for lubrication. This is due to suspended metal particles, soot, oxidation, etc... Had they tested new motor oil it would be a different story.

I have talked to someone that deals with backup diesel generators at nuke plants. In the reports he has gotten it shows that wear due to the low sulfur diesel fuel is only about 2% to 4% worse than normal diesel. Also in some batches they can meet the requirements with out using the extra stage to reduce the sulfur which reduces the lubricity (its not the sulfur that provides the lubrication). Also in most cases where a batch doesn't meet the requirements they run only part of it through the extra stage and dilute the other part of it until it does meet standards.

I have ran new motor oil in my fuel in the past to offset the btu drop in winter diesel (It works but isn't economical). I had no increase in smoke but then again my engine has a 21.5 to 1 compression ratio which will burn it more completely.

[UFO]

Originally Posted by ConnClark

You might note that they tested USED motor oil with 5000 miles of used and not new motor oil. The reason why people remove the motor oil from their engines in the first place is it no longer is suitable for lubrication. This is due to suspended metal particles, soot, oxidation, etc... Had they tested new motor oil it would be a different story.

I have talked to someone that deals with backup diesel generators at nuke plants. In the reports he has gotten it shows that wear due to the low sulfur diesel fuel is only about 2% to 4% worse than normal diesel. Also in some batches they can meet the requirements with out using the extra stage to reduce the sulfur which reduces the lubricity (its not the sulfur that provides the lubrication). Also in most cases where a batch doesn't meet the requirements they run only part of it through the extra stage and dilute the other part of it until it does meet standards.

I have ran new motor oil in my fuel in the past to offset the btu drop in winter diesel (It works but isn't economical). I had no increase in smoke but then again my engine has a 21.5 to 1 compression ratio which will burn it more completely.

I think you'll find that used motor oil (uncontaminated with other substances) has no issues with viscosity. The reason oil is changed is the additives are consumed, not because the oil itself breaks down. Read the thread "Changing oil is un-necessary".

New motor oil has the same lubricity as used, within reason.

[beatr911]

Aren't there commercialy available additives for this?

Adding a quart or two of ATF I understand helps as well. I run 20:1 used, filtered ATF in my diesel tractor. The ATF burns much cleaner than engine oil, can't speak to lubricity but no issues in 361 hours of use.

[ConnClark]

Originally Posted by UFO

I think you'll find that used motor oil (uncontaminated with other substances) has no issues with viscosity. The reason oil is changed is the additives are consumed, not because the oil itself breaks down. Read the thread "Changing oil is un-necessary".

New motor oil has the same lubricity as used, within reason.

The oil its self will break down. From the experts with no profit motive other than to get you to test your oil WearCheck FYI - Oxidation and Oxy-polymerization of Oils

[UFO]

Originally Posted by ConnClark

The oil its self will break down. From the experts with no profit motive other than to get you to test your oil WearCheck FYI - Oxidation and Oxy-polymerization of Oils

We are not talking about over-extended change intervals, the test oil was 5k miles, within a normal change interval. Anti-oxidation additives will certainly last that long. I've had oil tested at 10k miles with nothing out of spec, so I doubt you can make the claim the oil lubricity is significantly changed in 5k miles, or 10k for that matter.

[lowglider]

There are also commercially available diesel addtives that improve lubrication and do many other good things for your rig, I use them because they are made specially for diesel engines and also come cheaper than two stroke oil. Also, they do not cause any residue like two stroke and motor oil which can plug EGR valves and other pipes when used in diesel engines.