White Technicalities Issue 4

Covered in this article- Burner Nozzle Hole Size, White Sub-Burner, Flowmotor control, thermostat rod, modulating fire, dragging fire.

Quiz Questions

1. Can One rely upon the size of the holes in the main burner nozzle as specified in the Owner's Manual?

Ans- No. The Chemistry of fuels today is not the same as it was seventy years ago. The trick is to try bigger and bigger hole sizes until you get the burner to howl constantly, then go one hole size smaller. I use regular no-lead in the main burner because I get it anyplace while on tours. And I have a nozzle drilled for it. Around the place here I add 20% no.#2 Diesel to the no-lead. I have to use a smaller hole size when using this heavier fuel but the car has more pep and the burner stays on less each cycle. Straight no-lead is actually a little bit light for your White Steam Car. 

2. Can no-lead be used in the sub burner (on the New Regulation Whites)?

Ans. Not really. It will plug up the passages after a few hours running. Towards the end the flame gets dirty and yellow and then one has trouble with the main burner. Unlike the Stanley whose pilot burner in no way effects main burner fuel vapourisation, the height of the sub burner flame on the White does effect main burner vapourisation. There is only one satisfactory fuel for the White sub burner- Coleman Lantern Fuel or its equivalent. Coleman is expensive. CHEVRON make an identical lantern fuel and here in a 55 gallon drum, delivered to my farm, it is $2.35 per gallon. 

Using it, the sub burner in the Model M is now on its second summer and has not been out of the car. It's flame is just as pretty now as when I installed it over a year ago.

A White Pilot Light under test. Note the leak under the head. Photo Courtesy of R Dyke.

3. Assuming no leaks, correct burner nozzle for the fuel used, and all other regulators in factory condition, is the hole size in the flowmotor water by-pass important while driving at 15mph?

Ans. At that speed, probably not. The Flowmotor Piston will not have travelled far enough to open the by-pass.

4. Same as no.3, above, except the car is going 30mph?

Ans. Now the flowmotor piston has travelled its full one inch and the by-pass is open. If the by-pass hole orifice has been tampered with, the steam temperature will either climb or go down, depending upon whether the hole is too small or too large.

5. Assuming the flowmotor orifice is the correct factory size, at 30mph what other factor can cause the temperature to drop?

Ans. If the driver is heavy-handed, opening the throttle too quickly so as to accelerate the car rapidly, ANY monotube steam generator will draw cooler steam from the inlet side of its coils. Even so, the White system, if set properly, is good enough to correct this temporary situation in a few city blocks. 

If it does not do so, assuming other controls are correctly set, then either the burner nozzle holes are too small or the grade of fuel is too light. (It goes without saying that a plugged vapouriser or plugged nozzle holes will cause the same problem).

To put it another way, for whatever the reason, if the temperature stays down at 30mph, there simply is insufficient fire for the amount of water being admitted to the coils. The fire will also be on most of the time. ( The answer to question 4 also applies here).

Thus, it can be seen that flowmotor by-pass hole size, type of fuel, type of vapouriser, and burner nozzle hole size are all tied together when driving at high speed. 

6. Are the grooves milled into the thermostat copper rod important?

Ans. Yes. They increase the total area of copper exposed to the steam and thus, reduce the response time. When the system is calling for a correction, it is desirable to have the input from the thermostat quickly. Leave off the milled grooves and you will have a sluggish thermostat and, wandering temperature.

7. At 30mph the temperature holds close to 750F. But, driving around town at 15-20mph it slowly climbs up and overheats, causing the driver to have to shut off the main burner fuel valve. What should be checked first? The Thermostat or Flowmotor?

Ans. Flowmotor. If the thermostat were the culprit then the temperature would not have held as it did at 30mph. At slow speeds, the Flowmotor does most of the temperature controlling. And, if the temperature slowly rises, re-read what I said about Flowmotors earlier on in this letter. 

There are, of course, other things that can cause slow speed overheat and I mentioned a few of these earlier. 

8. The White Steam Car is said to have a "modulating" fire. That is; low fire at slow speed and high fire at high speed. Why is it important that a man tuning up his White understands what the "modulating" fire accomplishes?

Ans. Until he does understand, he probably will never get done tuning up his car. At age 95, he will still be playing with the Thermostat! 

The point to comprehend is this: At slow speeds, the water pumps deliver insufficient water​ to the generator for the amount of heat available. The Flowmotor offsets this fact by reducing the amount of fire. Besides, a big fire is not needed when going slow. It saves fuel too.

However, when going fast, the pumps deliver too much water for the amount of total fire available. The Flowmotor offsets this by by-passing some it back to the reservoir. Understanding the "modulating" fire idea and how Rollin White's Flowmotor made it all possible, is the real secret to tuning up a White Steam Car...

9. When the steam pressure hits 550 PSI, the red fire needle is slow about dropping off to zero. Will this cause steam overheat?

Ans. It is a primary cause. That needle should drop rapidly, bounce a few times, then die. Even at a mere 5-15psi, the needle hanging in there too long surely does cause overheat. 

Neither time nor space permit me to go into all the causes of "Dragging Fire". Besides, both your owner's manual and Edmonson's booklet cover it adequately. I will say the first thing to check is the Finnegan Pin screen in the water regulator. It must be kept clean in order to allow water to by-pass quickly once the Finnegan Pin opens.

10. When the car sits overnight, air pressure in the fuel tanks bleeds off. What is the cause?

Ans. Assuming all the air line unions don't leak and the lead washers inside the fuel caps and air compressor are good, the only place air can bleed off is through the the leather faced check valve or, around the rivetted head on the air compressor poppet valve. I've found it a good idea to put a little solder on top the rivet head on the topside of the poppet valve. The leather washer in the check valve is only good for a year and because it too is rivetted, replacing it on the road can be a chore. Best thing to do when one has this little valve apart is drill and tap a small threaded hole in the stem, then use a small screw to hold the washer in place. Next time one needs to replace the washer, simply remove the screw. I use NEOPRENE instead of leather as it lasts longer. ​

Dick and Lynda Hempel with their 1909 White M 40HP