Oil for a BIG Diesel

[Shel_B]

I came across this engine info quite by accident ... it's a little larger than your typical Diesel, and quite fascinating. What kind of oil system might such an engine have? Does it get regular oil changes, and what might the interval be? Would a standard HDEO work in such an engine, or might a special oil be used?

https://wonderfulengineering.com/worlds-largest-and-most-powerful-diesel-engine/

 

[wpod]

Lots of the huge diesel engines may have a system that oils the head and valve train and another source to lube the bottom I don't know exactly .

 

[Chris142]

A lot of big stuff,trains included use bypass filters and huge capacities. Only change when a uoa shows a problem.

 

[K-Man]

The story didn't say anything about the oil used.

Here's a website that discusses the oiling system, again with no direct mention of the type of oil.

http://www.machineryspaces.com/lubrication.html

This has more details:

https://shipfever.com/lubricating-oil-system-ship/

That site includes this information about the lubricating oil:

There are two separate tanks kept on board to store cylinder lubricating oil. In one tank lube oil is with TBN 70/100 is kept while in other TBN 30/40/50 is kept. The TBN stands for total base number; indicating the alkalinity of the lubricating oil.

A lube oil with high alkalinity/TBN is used against fuel oil with a high concentration of sulfur to neutralize the acidic effects of sulphuric oxides formed as the by-product of the combustion process.

In emission-controlled areas, TBN 70 is to be changed over to TBN 50/30. Further to ensure quick cutoff of tank supply in event of a fire; a quick closing valve is fitted at the outlet of the tank.

That leads to this site, which discusses desirable properties of marine-diesel lubricating oil:

https://shipfever.com/lube-oil-properties-marine-engine/

And after some digging, I found an example of the oil these behemoths use:

https://colemanoil.com/marine-lubricants

CHEVRON VERITAS® 800 MARINE OIL SAE 20, 30 is a premium crankcase lubricant for low speed crosshead type diesel engines. Veritas 800 Marine is manufactured from highly refined lubricating oil stocks and has very good anti-corrosion and anti-foam properties. The oil has a moderate level of alkalinity to neutralize acidic combustion products that can enter the crankcase. Special additives give the oil detergent properties which ensure clean crankcases. The combination of detergency and the excellent oxidation stability provides clean piston interiors where oil is used for cooling. Veritas 800 Marine is recommended for the crankcase lubrication of large, low speed crosshead type marine diesel engines and meets the Wärtsilä-NSD (Sulzer), MAN-B&W, and Mitsubishi crosshead engine system oil requirements. Due to ingress of higher viscosity cylinder drip oil into the SAE 30 system oil, the viscosity often shows an increase. The SAE 20 grade will help to economically correct this viscosity increase.

Maybe Amsoil could look into this market.

Seriously, one change has taken place since the original article was posted: container and cargo ships used to travel at speeds of 25+ knots, but about 10 years ago, to save costs and emissions, most restricted speeds to about 10 knots. Of course, this makes transit times much longer.

In case you wondered, the fuel in these huge two-stroke diesels used to be "bunker fuel" or "bunker oil", essentially the thick leftovers from refining crude oil. There has been a push to use other fuels in recent years.

 

[Spike555]

Most of those super large marine engines never get a oil change. They take to much. They keep them full and nothing more. Hundreds of gallons of motor oil.

20w-50 was specifically developed for the Queen Mary’s engine By British Petroleum.

 

[carviewsonic]

An article I read a couple years ago said that typically 30wt was used for the bottom end, and 50wt was injected at the top end.

 

[ctechbob]

Can't remember where I read it before, but I believe most of the really big units will use multiple centrifuge systems for cleaning the oil as well. Not much gets through those as far as contaminants.

https://www.gea.com/en/products/cen...gal-separator/separator/separators-marine.jsp

Something like that. If you're keeping the oil that clean, there's not much of a need to change it.

 

[2EHA]

tired: real engines have pushrods

inspired: real engines have no camshafts

20w-50 was specifically developed for the Queen Mary’s engine By British Petroleum.

it was made by duckham’s for the mini

 

[nthach]

I rode past a wharf for Valero here - I saw drums of what appears to be Castrol’s marine oil on a Eaglestar oil tanker.

 

[Shel_B]

This has been a fascinating discussion. Thanks for all the comments.

Considering that some of these big engines turn at very slow RPM, does the oil reach temperatures that it does in some cars, 225-deg or more? If the oil doesn't get very hot, then might there be some additional way to get rid of contaminants that usually burn off, perhaps with the centrifuge pumps?