I saw a 1930 Harley-Davidson VL at the Daffodil Festival in Camden. That started me thinking about how things have changed since the day it rolled out of the door new. That day was just 27 years after George Wyman made his trek across America in 1903. I talked about that epic journey in a previous blog. It is almost three times that number of years to the present day, and things have changed a lot since then.
Looking at this 80-year-old machine I would expect to be enamored by the primitive design. Instead, I was impressed with the marvelous engineering. This thing was perfectly adapted to the world it inhabited. I mentioned the chain oiler in my last blog. But that’s just the last step in the oil’s trip through this old engine. It starts out in an oil tank waiting to be injected to the engine by a pump knob mounted close to the gas tank. This old motor actually consumed the oil. Pressure from the piston blew it into the valve cover. A tube allowed excess oil to drain onto the chain, so a shot of fresh oil from the oil tank was occasionally necessary.
This may sound like a waste of oil, but it really wasn’t in 1930. The 1930 flathead V-twin engine used a dry clutch, but had a wet transmission. Motor oil bathed the transmission where it was ground between the gears in the heat of an air-cooled engine. Modern motorcycles can take advantage of modern synthetic and semi-synthetic oils, specially designed to take the punishment of such a harsh environment. That wasn’t the case in 1930. Oil in those days was refined from crude with a clay and solvent process, and would usually contain about 15 percent wax and paraffin. That primitive oil took a real beating in a motorcycle engine, and just didn’t last very long. So Harley decided to let the old stuff drip out and replace it with new. But the used oil was still good enough for a chain lube, so they used it for that.
So it turns out that the oil spot on the ground where that old bike is parked isn’t a sign of bad engineering after all. It’s the result of a good engineering solution to the oil and usage of its day.
— Guy Wheatley