R.D. 2, Middletown, Maryland 21769
I read the OIL PULL TUNE UP article by C. E. Stambaugh in the September-October 1972 issue, with great interest and knowing Bud Stambaugh over the past few years, I feel that he is one of the top experts with Oil Pull Tractors.
His method of adjusting valves on light weights is correct and should be rechecked on a hot engine due to the push rods and rocker arms being enclosed. The older 12-20, 16-30,2040 etc. had open push rods and rocker arms and there was very little difference in valve clearance between hot and cold, due to cylinder heat expansion exceeding open push rod heat expansion.
Now, I would like to refer to the remarks by Frank J. Burris, 35640 Ave. F., Yucaipa, California, which I read with concerned interest.
My reason for writing this article is that I've worked around Oil Pulls many years, beginning with an Old 20-40 purchased by my father in in the early 20s and traded on a 30-50 Y about the time Rumely Company changed to Allis-Chalmers.
Mr. Burris remarks that he discarded the use of a water tank on a 20-35 Oil Pull and is operating the engine on pure gasoline. I am sure Mr. Burris is aware of the danger if this Oil Pull should come up to its normal heat which is over 200 degrees and there should be gasoline fumes in the crankcase. I remember one old 12-20 that exploded in the crankcase from using gasoline and blew both cylinders loose from the crankcase. I also remember a 30-50 Y and a 2545 light weight exploding and blowing the crankcase inspection cover and timing gear covers out.
All of these Oil Pulls were built to run on a mixture of kerosene or a crude type oil and water and were oil-cooled due to extremely high operated temperatures. This was their method of developing power. These old Oil Pulls didn't have much of a crankcase ventilating system and no one seems to know if the fumes exploded from the return vent to the carburetor or just plain heat and agitation in the crankcase from gas fumes.
One fault with many Oil Pull operators was due to the lubricator which fed oil to the cylinders and main bearings. This lubricator would go through one to two gallons of oil on a hard days work and the surplus oil would spill into the crankcase keeping it full, therefore the operator would very seldom drain the crankcase to get rid of accummulated contamination.
I remember a beautiful, practically new light weight 30-60 that developed a cracked engine head, burned exhaust valves and top piston rings due to the owner deciding he could cool the engine with water and burn gasoline. This engine also had the restricter either rusted out or removed from the cooling circulator which allowed on cylinder to run hotter than the other.
I suppose I've talked long enough about Oil Pulls, but I still love to hear them run and when it comes to pounds of fuel per horsepower, I don't think there was a more economical engine in the field at their day and age. We used to drive a 30 x 52 Red River Special Thresher from early morning till dark on 30 to 35 gallons of kerosene.
So, Mr. Burris, I know you'll enjoy playing around with your Oil Pull every minute, however, I would like to suggest that you put the water system back on this old boy and give it a longer life of original operation. Your ten degree timing for gasoline is very good, but if the oil restricter is still in proper place, which I am sure it is to equalize the heat to both cylinders, the engine temperatures will still climb above 200 degrees.