Re: Does any one capture and re-use their steam oil?
Posted by:
Peter Brow (IP Logged)
Date: July 24, 2008 09:46AM
Hi Caleb,
New idea. Why not add skimmer pump to the main pump box, which is right on top of the water tank, in my system (and Stanleys) anyway. Perfect place for feedwater and skimmer pumps, and the drive is already there. The pump can be tiny (like 1/8" bore x 1" stroke), should take almost no power, and its plunger would move with the water, fuel, and lubricator pump plungers. Make it pump just a bit more than the lubricator pump. If driven by the engine, the skimmer pump would always pump exactly enough oil out of the main water tank, just a bit more than the lubricator pump puts into the tank by way of the engine and condenser. No problems with estimating how many miles/how much oil per brake pedal push, brake lever pull, or pendulum swing.
This is one of those "I can't believe it took me this long to arrive at such an obvious solution" things.
However, I am still not sure about the skimmer-pump system, at least for my project.
Kent: "The cylinder oil consumption ranges from 0.1 pint to 4 pints per million sq. ft. of surface swept over by the piston (perimeter of piston x distance travelled), with an average of 0.8 pints per million sq. ft..". Pp. 7-47 to 7-48, 1936 edition. There is more interesting stuff in that section, including a note that oil does vaporize in 700-750F steam lines, and condenses on (exhaust-cooled) swept surfaces in the engine.
Stanley oil rates (and oils) vary, but one 20 HP Stanley factory recommendation (Stanley Dealer Bulletin #134, 3/14/1921) which I have seen is 300 miles per gallon. That's one quart per 75 miles. Slide valves need more oil than piston or poppet valves.
What sort of oil to use in steam automobile engines is controversial; even the manufacturers changed their recommendations from year to year, and I do not presume to recommend oils for either new or antique steam cars. Caveat emptor.
I personally plan to try the 40W non-synthetic ND motor oil in my new/hobby/experimental steam car, and will note that this is what Doble originally used -- though later Doble owners disagree with him on this, some stating that this oil was inadequate for the conditions and ruined engines.
One tip I got is that if a "classic" steam car engine is under-oiled, it will "groan". Then, increase oil pump delivery until the groans stop. Kent warns that too much excess oil will carbonize with highly superheated steam. Some lube pumps are adjustable; I plan to build and test a design very similar to the Stanley Model 735 adjustable-stroke lubricator, illustrated in the 1918 booklet "A Complete Description of the Stanley Steam Car". This booklet is available in reprint.
40W ND motor oil is available at some auto parts chain stores and mom & pop groceries. Shop around. Coastal and Chalet are 2 brands which I have seen; there may be others. Many years ago I spotted an obscure brand of ND motor oil, in groovy retro containers, that was marketed to owners of antique/classic gas cars with original engines and enough mileage/crud that you'd blow the engine with detergent oil. Look for the big ol "ND" on the label, though with some brands you have to look at the fine print on the back to see if it's non-detergent or not. If it doesn't say, it's probably detergent oil.
Shell Oil also makes the very model of a modern mineral motor oil, non-detergent, in various grades including 40W, for aeronautical engine break-in. This stuff is called "AeroShell ND" and can be sourced at small-airport pilot shops (if you can get past security back in the USSA), or a friendly Shell station or distributor can order it for you.
Peter
Edited 1 time(s). Last edit at 07/24/2008 09:57AM by Peter Brow.