Diesel Oil Change every 24-36 hours?? 3

[BamBam.a]

Hi Guys!

I just came across an old writing from 1968, that said the engineer was required to change the Engine Oil every
24-36 hours of run time with either new oil or freshly processed lube oil.

There was no description of the engine manufacturer, model or year in this writing, just that it was a generator in what I assume is
a ship.

Im just curious, what would require such frequent oil change? It seems excessive to me. and also, "processed lube oil" are there
ways to condition old oil for reuse, by the end user?

Thanks

 

[BrianPetersen]

Probably because motor oil back then was nothing like what it is now.

Probably because internal tolerance inside the engine, etc are nothing like what they are now.

Probably because fuel contaminant content, notably sulfur, was nothing like what it is now. (Sulfur when burned + water + leakage past piston rings = nasty contamination in the oil)

Probably because fuel injection and ignition and combustion systems back then, are nothing like what they are now.

And if you don't know the specifications of the engine for which that recommendation applied, we (on the other end of the internet) certainly don't.

 

[Lou Scannon]

Maybe a Westerbeke

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[BamBam.a]

BrianPetersen,

Yes, you are probably right, engines and engine technology, in the late 60's was nothing like it is now.

I hope you didn't read my OP as a question as to who the manufacture was. I thought I was being careful to not put
a question mark after that particular statement.

I'll be more specific with my question: Make believe you are running a 125kw generator with a diesel engine of unknown manufacturer, out on a ship, in the Atlantic ocean, in the
late 60's. The engine, you have been told, requires a complete oil change, every day. Would you not think that maybe something was wrong with the engine, or would you
consider this to be a normal type operation in a marine environment?


The sulfur is a good point though. I wasn't thinking with fuel quality.


Hemi: or a WalkToShore

 

[Compositepro]

Back in the 50's and 60's Ship fuels were little more than slightly purified crude oil. Sulfur was not removed. There was little difference between diesel fuel and lubricating oil. The sulfuric acid created by high sulfur fuel would be very corrosive to an engine when the blow-by condensed in the oil. The oil could be changed every day and added to the fuel.

Back in the early 80's I worked at a chemical plant that got shut down due to a recession. We sold an inventory of one chemical overseas but it turned out that it failed a color spec. The material was stored prior to shipment at a tank farm in San Pedro. As a Process Engineer involved in the plant closure I was assigned to watch the reprocessing of the material at night, where we were used a steam driven piston pump on a skid at the tank farm to recirculate the tank through a carbon bed. One night I observed that the lubricating oil in the pump was low, I informed the night watchman. He then got an old bucket and went to several crude oil tanks and opened the drain valves on the level gauges. When he found one that would drain, he filled the bucket and topped up the lubricant on the pump. Oil was oil.

 

[TugboatEng]

I would assume that this is an engine with a non-detergent oil and no oil filter. Without a filter you must rely on changing the oil to remove contamination.

 

[BrianPetersen]

Put it in automotive terms. In the old days, it was recommended to change the oil every 3000 miles. (It may have been even more frequent once upon a time, but in the 1960s and 1970s, that was not an uncommon recommendation.) If you average 50 miles per hour, that's every 60 hours. If the engine is actually running full load (like the engine in your generator might be), it may actually drive the car 100 miles per hour; that's every 30 hours.

 

[GregLocock]

I can't remember the engine service interval on my TR4, but the suspension bushings had to be greased every 1500 miles.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[TugboatEng]

A very good rule of thumb is that 100 hours is 3000 miles.

 

[Hoxton]

In my time with continuous running engines, clients used to get surprised at what they saw as short service intervals.

I used to point out in comparison to cars that if you took the typical life of a car as 100,000 miles, then at an average speed of 40 mph, this only took 2500 hours.

There are 8760 hours in a year, so in very round numbers, that’s a third of a year!

OK, there’s a difference between stop – start duty, which is what a car does, and continuous operation like in a power plant or pump, but it does focus the mind to realise what the task is with a continuous duty set.

With my example, with oil changes every 3000 miles, that equates to an oil change every 75 hours, so it all stacks up.

 

[catserveng]

In that time frame both propulsion and ships service generators were likely running HFO, bunker or residual fuel oils.

A lot of older slow and medium speed engines in that service required near constant oil treatment mostly thru a system of filters and purifiers at a rate that caused the entire lube oil system volume to be processed in a 24-72 hour period.

The "oil change" likely being talked about in that document was the volume change in oil for treatment thru the oil cleaning and replenishment systems.

For example, on an older B&W 2 stroke low speed engine at a plant I worked on for several years, the operating instructions required that the lube oil be cycled thru the oil treatment system ata rate to cycle total volume of the lube oil system with 48 hours under constant load. It also required the lube oil system for the turbocharger, which was separate from the crankcase lube oil system be fully cycled at a rate thru its own oil treatment system that would treat its total volume every 24 hours.

Here is a short description of a slow speed marine engines lube oil system operation, hope you find it helpful,

https://www.marineinsight.com/tech/ships-main-engine-lubrication-system-explained/

MikeL.

 

[BamBam.a]

Hi Y'all


Thanks for all your answers.!

I will check out that link for 2 strike lube oil system.

Thanks again.

 

[romke]

four stroke diesel direct injection engines running on diesel fuel in construction machinery in the early seventies usually had oil change intervals of about 100 hrs if equipped with a half decent oil filter. the fuel usually contained 0,7 % sulphur. indirect injection had shorter intervals due to the less efficient combustion, that resulted in rapid oil thickening because of soot getting into the engine oil due to blowby gases.

oil change intervals have changed considerably over time: truck engines got a oil change at about 5000 km in 1970 and nowadays around 150000 km - 30 times as long in modern engines that have a specific output that is about three times higher as the engines from the 70's. both oil quality, engine quality, fuel quality and accuracy of the injection equipment has made this increase in oil change interval possible.

 

[TugboatEng]

The biggest influence on oil change interval for trunk piston engines is the oil capacity. Caterpillar even sells engines with different oil change intervals. The 3512 engine is available with a 500 hour and 1000 hour oil pan. The difference is a 75 gallon and 165 gallon capacity. Of course we stretch ours to 1500 hours.