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THE WHITE FLOWMOTOR CONTROL SYSTEM.
Throughout the history of the steam car, several successful firms used the forced circulation monotube type of steam generator in automobiles, often called the “Flash” boiler.
Use of such a generator demanded that the maker also evolve a control system that would regulate both the steam pressure and the steam temperature, and keep them as constant as possible no matter what the driving conditions encountered.
Three firms succeeded: The Serpollet in France and the White and Doble in the United States. Other steam cars like the Scott-Newcomb also used this type of steam generator; but never reached commercial production.
The Doble brothers applied electric controls to their vehicles; but in doing so, they managed to also introduce complication and serious maintenance requirements.
Rollin White devised two different types of fully modulating control systems for his cars, and this paper will address only the second version, the one using a flowmotor to serve as the main control device. However, all three of the control devices work in concert, the flowmotor itself, the thermostat and the pressure regulator.
The White system demands that a high degree of precision be employed when restoring one of these cars. Any water leak or malfunctioning water pump will upset the control functions. As will a clogged burner vaporizer or nozzle.
The White steam car must be maintained in peak condition to function as intended. Also, unlike the Stanley or Doble cars, the White does not accept any modification, restoration has to reestablish the original factory clearances and for them to be maintained. Once restored correctly, the White will run for many years.
In the White steam car of the 1907 to 1912 period, a totally mechanical, fully proportioning analog system, with two overrides for pressure and steam temperature, was brought to a state of high perfection. So confident was the White Company in the reliability of their control system, that the only manual valve available to the driver was the main fuel shutoff valve, everything else was fully automatic.
The White steam car also had several notable features in it’s design that serve to well illustrate the high level of engineering that Rollin White put into his cars.
First was a piston valved compound engine that ran on ball bearings and used the simple Joy valve gear in the 1909-12 cars. The White engine was most often singled out in engineering reports as having a water rate of some 12 lbs/hp/hr, which was very good for that era. Combined with their efficient condenser it served to give the White a range of about 150 miles on a tank of water, much more than the contemporary Stanley steam car.
A very potent low pressure, pre mix vaporizing burner that was quite able to maintain full steam pressure at any speed. The fuel vapor was mixed with air after the liquid fuel was converted to a gas by heating it in the vaporizer. This burner also featured an easily removable vaporizer without having to drop the burner, that had convenient cleanout plugs for the occasional removal of carbon.
A very nicely designed adjustable pilot light that could be removed in moments for cleaning, by unscrewing one pipe union. The bayonet mounting made removal particularly easy. A slight twist and the entire pilot light came out in the hand. This pilot light was the main source of heat for the main burner’s fuel vaporizer and, as the pilot had a needle valve in it to regulate the intensity of the fire, a fine adjustment of the flame was possible. Setting the pilot light to a low flame when parked for any appreciable time, meant that the main vaporizer would always be kept hot for an instant getaway, and also not overheat it. This pilot light burned straight white gasoline, as did the main burner until 1910. Kerosene could then be used in that year in the main burner by changing the vaporizer for a different one. Today, the cheapest unleaded gasoline works just fine.
A big engine driven fan with a high flow rate that kept a good draft of air going through the condenser.
A vacuum pump that served to not only return the condensed steam back to the water tank; but maintain a modest vacuum on the condenser.
An efficient feedwater heater in the engine’s exhaust steam manifold.
Last, a two speed transmission that was built into the differential with the most useful feature of having a neutral position, one of White’s most important ideas.
One paramount requirement must be observed when restoring one of these White steam cars, or the vehicle will simply not operate as it did when it left the factory. The White does not tolerate free spirited improvisation to any of the components and people who insist on modifying the three basic control components often find their White not controlling properly. A lesson that unfortunately has to be learned the hard way for some.
When restoring a White steamer, it must be returned back to the original condition it was in when it left the Cleveland factory if successful running is to be had. Observe this rule and one has a fine and very dependable vintage steam car capable of years of enjoyable service. Ignore it and the car is a constant source of irritation.
It would be helpful to first describe the construction and operation of the three basic components in the White system, then to go on and describe how they interrelated with each other.
The White system has three basic components, using the White terminology: The Water Regulator, the Thermostat and the Flowmotor.
The water regulator is a spring loaded diaphragm valve that bypasses all the water back to the storage tank when it reaches the proscribed steam pressure.
The thermostat is an expansion device that uses a copper rod in a cast iron housing, and the difference in the expansion rates of copper and iron serve to operate a proportioning needle water valve. The valve adds additional water to that passing through the flowmotor in a very novel manner, and serves to keep the steam temperature under control.
The flowmotor is a rate proportioning device with a spring loaded piston that reacts to the varying flow of water from the pumps by progressively opening a tapered fuel valve that allows fuel to pass on to the burner. It also had a water bypass valve that operated when the correct flow of water to the coils was reached, sending the excess water back to the tank.
THE WHITE WATER PUMPS.
There is one other notable feature of the White steamer that is often overlooked. The two plunger type water pumps will deliver 100% excess water to the system when on a level road, at 18 mph with the two speed rear axle transmission in high gear.
These two water pumps use ball check valves for both inlet and discharge. Often one finds that previous owners have reground the removable seats so often that the balls are quite low in the pump barrel casting and this reduces the water delivery rate by shrouding the check valve balls. It causes a restriction in the water flow and the only solution when this condition is serious is to make new seats.
A good guide today is to observe the finish on the check balls. When new they are bright and shiny; but when the seats are low in the pump, they take on the appearance of being dull and have a frosted appearance. This means that they have been buzzing around on the seats and now the pumps will not give the amount of water the car needs to properly control, because they are now shrouded and are not seating properly. The correct repair is to make new seats with the proper height. The Edmonson’s Manual is of great help here.
Should any pitting or a seating area discoloration be noted, remove the old ball and put in a new one. Experienced White owners carry a few extra ones in the car.
Also, the valve caps have a small protrusion on them that limits the lift the check balls can have. The Edmonson’s manual, which was based on factory information, says that the clearance between the ball and the tip of the protrusion will be 1/32” for the half inch pump balls and for the five eights line check balls, a lift of 3/64” is proscribed and they mean it too. Anything different and the water delivery rate is changed from what the car should have. This is measured with both a depth and ordinary micrometer. The tips are brazed up and then cut down to give the correct ball lift.
It is critically important that the White water pumps be in perfect condition, as their correct delivery rate is the basis for correct operation of the car. A close fit between the pump pistons and the bore is required.
Fine finish grinding and hard chroming the pump plungers insures a long packing life.
One other component in the water pump system that has to be in good condition is the spring loaded water cushion on the discharge line from both water pumps. White provided this to eliminate water hammer in the plumbing and also any bouncing of the various water control valves. It is a simple bronze cylindrical housing that contains a piston that sees the pump discharge, and a strong spring to push it down.
If the spring is weak, the cushion piston flys up too early and the cushion effect is lost. With age and use they usually are indeed weak and should be replaced.
Should the piston bore in the cushion be badly worn and as a result is bored out and a new piston made, it is necessary to recalculate what the spring pressure will be at 600 psi and secure a new spring that matches the same pressure that the smaller original spring provided. The piston should be about half way up the cushion bore when the car is operating at the correct pressure.
THE WATER REGULATOR.
This water regulator is the pressure control for the White steamer. When the bypass valve opens up, all the water now goes back to the tank and the flowmotor thinks that the engine is stopped, as no water is coming into it and the spring in the flowmotor pushes the piston up and closes off the fuel valve, thus shutting off the burner.
This is a small bronze assembly that sits on the side of the engine where the pumps are located. It has a brass diaphragm that sees the steam pressure in the generator and, via a lever, open or closes a water bypass valve.
It contains a really massive and strong spring that loads the diaphragms against the steam pressure. So strong is this spring, that in place of the usual threaded gland to adjust the tension of the spring, White used a worm gear inside the housing, with a little shaft protruding through to the outside with a packing gland. A special wrench is used to adjust the steam pressure by increasing or releasing the spring tension against the diaphragms.
The diaphragm pushes a little pushrod against a lever inside the regulator housing that magnifies the motion and it opens a little water valve that allows the water to go to the steam generator or go back to the tank. This valve is always referred to as the “Finnigan Pin”, why is totally unknown. And, it often has a most amusing feature when it is just starting to open up, it squeaks in time with the water pump pulsations. A little hard on the valve’s seat; but it is a sure indicator that the water regulator is working. The periodic chirp is an audible indicator that the water regulator is doing its job.
The clearance between the Finnegan pin and it’s seat is supposed to be 1/16” to 5/64”. Deviation will upset the flowmotor piston by causing it to bounce and that wears out the fuel valve if the lift is too small.
The Finnegan pin is also protected by a little bucket shaped screen insert inside the water pipe. If this screen gets clogged with packing, which it does, the effect is the same as the regulator pin not opening enough. It should be cleaned every day before setting out. This can be seen by a very slow return of the fuel vaporizer pressure gauge needle on the fuel duplex gauge. It should drop quickly when the screen is clean.
This steam line to the water regulator and dashboard pressure gauge is always to be filled with cylinder oil via a valve under the floorboard and by using the manual lever on the lubricator on the dashboard. A hinged cover over this valve on the floorboard right under the lubricator tank is provided for easy access to the valve.
This serves to dampen any rapid pulsations in the steam line caused by the engine’s HP inlet valve opening and closing and causing the steam pressure gauge needle to fly all over the place. If the steam pressure gauge needle is bouncing, it needs oil pumped in. A daily check and a few pump strokes are suggested.
A word to the wise for White owners: This lubricator does not have any indicator to show that oil is actually being pumped into the steam line. A bobbing pin on top of the lubricator is provided, which only shows it is working; but should something block the inlet of the oil pump, this indicator goes ahead and bobs up and down; but actually no oil is being pumped. A dead fly once ruined a 40 hp White cylinder block, which then had to be rebuilt.
One other problem area is that ratchet clutch on the engine side of the dashboard that drives the lubricator pump. If the little rollers are badly worn, the springs are broken, the pins are missing or worn down, or if the shaft is badly worn letting oil get into the ratchet, then it will not drive the pump; but simply slip. This must be checked from time to time. An O ring on the shaft puts an end to this potential oiling problem.
The writer installed a non-condensing Stanley winker on his White’s dashboard to give a positive indication and great peace of mind that the oil was really flowing and the engine valves were not being damaged.
THE FLOWMOTOR.
Now that an ample supply of water is there from correctly rebuilt water pumps, the next and most important part of the White system is the flowmotor, the very heart of the White system. This is a bronze casting that contains a spring loaded piston, a packing gland on the bottom that has the fuel needle pushrod going though it to the fuel valve mounted on the bottom of the flowmotor, and a bypass water valve on the top of the whole assembly. These flowmotors are often warped from freezing up in the past and the bore is often oval shaped and must be Sunnen honed completely cylindrical. In the 1907-8 flowmotors White provided a tiny drain plug for totally draining the unit; but did not provide this drain in the 1909-10 flowmotors for some reason.