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IC engine lubrication

Posted by ReubenT 
IC engine lubrication
February 29, 2016 09:12PM
What is it that mixes the oil and water in the crankcase? Is it the oil pump picking up from the bottom of the sump that sucks up condensate that settles? If that's all it is and not the action of oil flinging away from the bearings. How about draining the oil pan to a separate container, perhaps bottom fed, and have a floating oil pickup. But there's the steam leaking past the pistons, condensing and getting shear mixed with oil on the walls of the cylinder, at least until the cylinder heats up to above boiling temp. That might negate the idea.

Another option, synthetic oil with MBL, (metal base lubricant) for maximum lube, run off to a separate container and heated with exhaust steam pipe to drive off water, an insulated sheet metal auxiliary reservoir would heat up fast and start sending water vapor out a vent. Heat it in the crankcase and it would be condensing on the walls until the whole engine came to above boiling temp.

Just wondering if either has been tried.
Re: IC engine lubrication
February 29, 2016 11:15PM
Generally speaking, the problem isn't the oil. Relatively pure mineral oils don't hold much water on their own, it's the additives that do it. Of these, detergents are the worst offenders. A detergent molecule has two ends, one of which is hydrophilic .... meaning it loves water. Non detergent oils will be a big step forward. The problem is that non-detergent oils aren't necessarily free of detergents. If manufacturers find that the detergent component in the oil is less than the required specification, they may label it as non-detergent and they are simply stating that they can't be held liable for improper detergent properties.

If you get turbine grade oils, they are formulated for minimum emulsion. It's been some years but, as I recall, the maximum water emulsion that 2190 TEP (the grade the Navy uses in propulsion turbines) can carry is 3 to 5 percent; far too little to form the notorious "mayonnaise". In still conditions gravitational settling readily separates this out, while centrifuges do likewise much more rapidly under adverse circumstances. Water DOES evaporate at lower temperatures than oil, especially if you can reduce the pressure in either the crankcase or (probably better yet) a dry sump. Pass oil from a warm running engine through a vacuum chamber and the oil will flash out of suspension.

Gotta watch absolutely pure oils, however. Some of the additives may be anti-foaming or extreme pressure, possibly necessary for good operation. That's what the TEP in 2190 TEP stands for....2190 means that it is a class 2 oil with a viscosity of 190 Saybolt seconds. TEP referred to the additives. T meant that it was turbine grade and would specifically repel water from oil and prohibit oxidation of metal surfaces. EP meant that it contained mild Extreme Pressure additives so that it could handle the loads placed on ship's propulsion systems.

None of this should be a huge surprise although there seems to be some kind of idea that water will automatically emulsify heavily with oil. The old Westinghouse high speed single acting units used to have quite a bit of condensate in the crankcase and they would just pour it off after stopping the engine ... back in those days they had no additives.

Edited 1 time(s). Last edit at 02/29/2016 11:18PM by frustrated.
Re: IC engine lubrication
March 01, 2016 05:51AM
The biggest problem with substituting classes of oils is that generally you have no idea of what is the velocity. In the example above, I mentioned 2190 TEP having a Saybolt viscosity of 190 ... which certainly is not equivalent to an SAE viscosity of 190.

Attached is a nomograph that allows you to convert between various measurements of viscosity. It is recommended that one use the 210 F column under Saybolt as SAE oil grades are determined at 212 F, the 2 degree difference is negligible.

There are any number of products out there but one has to remember that running off the recommended application always poses some unknowns --- meaning I ain't giving no guarantees..... A couple of quick examples:




Edited 1 time(s). Last edit at 03/01/2016 06:03AM by frustrated.

Re: IC engine lubrication
March 01, 2016 05:23PM
Very interesting. Thanks for the explanation. Will have to get some of that oil, see how it works with water. I happen to have one of those "high speed" Westinghouse engines that I found on ebay last fall, a small one made by ACME under license, 1885 patent date. about 3 ft tall, a few hundred lb. It was sitting at $1000 starting price, one bid up to the end, so I dropped a bid at the last minute and got it for $1010. Our car hauling truck happened to be in PA at the time so my shipping was free. It will be the first to get going soon as a boiler is done. Good size to run a number of small things, like sorgum press, grain mill, generator, etc. And I hadn't figured out what oil to use yet. Condensate release during warmup is vented to the crankcase. And there is a plug and a valve on the side, I suppose procedure is to drain lower plug till oil starts to appear, and then add oil till it comes out the upper valve. I also need to know if a steam line oilier was used with them for cylinder lube. And I have no idea what speed they run at. Called high speed, but normal was maybe 250 RPM for medium size engine.
Re: IC engine lubrication
March 01, 2016 07:43PM
So I wonder how well this oil would work. [www.amsoil.com] Even though it's a gear oil, it pours like engine oil when cold. I used it in a one ton truck transmission and differential and then drove it for a month steady pulling a 20,000 lb trailer. (actually the whole drivetrain was from a 2.5 ton truck) But that wasn't with water contamination. With a gas engine getting 5 mpg and gas at $3.50-$4.00 a gallon we weren't making enough money to keep it up. I might just try both it and that turbine oil and see how they compare.

Edited 1 time(s). Last edit at 03/01/2016 07:44PM by ReubenT.
Re: IC engine lubrication
March 01, 2016 08:03PM
Use steam cylinder oil 460 Im kind of secretive about the oil I use in converted to steam IC engines.
Re: IC engine lubrication
March 01, 2016 08:44PM
Just remember that the cold pour viscosity isn't important. Different oils change viscosity in different ways with changes in temperature. It's the hot running viscosity that is really important.
Re: IC engine lubrication
March 02, 2016 02:40PM
Yes I agree steam cylinder oil 680 is designed for higher temps and this is what I lubricate my superheared intake valve stem with.
Re: IC engine lubrication
March 03, 2016 10:35PM
So the cylinder oil is used in the crankcase, I was thinking it was just for steam line insertion. I have 5 gallons of green velvet cylinder oil already.

I found just a little info on a museum site. But it's for a somewhat larger engine than I have. This one has piston valves but the small one I have uses a rocker valve across the top of both cylinders operated by a eccentric on the inside of the flywheel which is pulled to the center reducing it's throw by the governor in the flywheel.


Finally found a picture of one other than mine. Except mine has a much larger flywheel. [newsm.org]

This one is mine, [www.flickr.com]

Edited 3 time(s). Last edit at 03/03/2016 11:23PM by ReubenT.
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