A Pair of Model Oil Pulls

By Staff
Published on February 1, 1987
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A pair of Rumely OilPull models built and owned by Jim Patton, Hiawatha, Iowa. In front, a double cylinder model completed in 1986; in the background a single cylinder design done in 1980. Behind the OilPulls is an Eagle 6 tractor owned by Richard Grimm,
A pair of Rumely OilPull models built and owned by Jim Patton, Hiawatha, Iowa. In front, a double cylinder model completed in 1986; in the background a single cylinder design done in 1980. Behind the OilPulls is an Eagle 6 tractor owned by Richard Grimm,
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Figure 1 : For his double cylinder OilPull model, Jim Patton used lightweight aluminum pistons and fabricated entirely new connecting rods from steel tubing. This eliminated many of the problems in balancing the engine. The finished tractor shows very lit
Figure 1 : For his double cylinder OilPull model, Jim Patton used lightweight aluminum pistons and fabricated entirely new connecting rods from steel tubing. This eliminated many of the problems in balancing the engine. The finished tractor shows very lit
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Figure 2 : Jim Patton at the wheel of his single cylinder OilPull model. Completed in 1980, it has been displayed at a great many shows and has walked through lots of parades.
Figure 2 : Jim Patton at the wheel of his single cylinder OilPull model. Completed in 1980, it has been displayed at a great many shows and has walked through lots of parades.
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A 1985 photograph shows the double cylinder OilPull engine under construction. Two Fairbanks-Morse 3 HP 'ZC' engines were used, with the two cranks welded together. The two engine frames are mounted on a heavy steel plate to maintain alignment a
A 1985 photograph shows the double cylinder OilPull engine under construction. Two Fairbanks-Morse 3 HP 'ZC' engines were used, with the two cranks welded together. The two engine frames are mounted on a heavy steel plate to maintain alignment a
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By early 1986 Jim Patton's double cylinder OilPull was nearing completion. Shown here is a head-on view from the operator's platform that illustrates the general arrangement. Although both models are equipped with rubber tires and use modern technology wh
By early 1986 Jim Patton's double cylinder OilPull was nearing completion. Shown here is a head-on view from the operator's platform that illustrates the general arrangement. Although both models are equipped with rubber tires and use modern technology wh
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At this point in time the two engine frames have been aligned and mounted to a heavy steel plate. The crankshaft has been installed, and trial counterweights are attached to the crank throws. After some experimenting and adjusting of the counterweights, a
At this point in time the two engine frames have been aligned and mounted to a heavy steel plate. The crankshaft has been installed, and trial counterweights are attached to the crank throws. After some experimenting and adjusting of the counterweights, a

R.R. 1, Box 28-A Atkins, IA 52206

Nearly ten years ago, Jim Patton of Hiawatha, Iowa started
collecting pieces to build a model of the Rumely OilPull tractor.
The plan was to build a single cylinder tractor which strongly
resembled the original OilPull design. However, in order to make
the model suitable for parades and other events, rubber tires were
used instead of steel wheels, and the drive train saw extensive
modification from the original design. In other words, Jim was
concocting a design that looked like yesterday’s technology,
but embodied a lot of modern engineering design as well.

The first of Jim’s OilPull models went into actual
construction during 1979, and was completed in 1980. Weighing about
800 pounds, it is small enough to fit into a pickup or onto a small
trailer. This makes it an ideal model to take to a show or to a
parade.

Shortly after completing the single cylinder OilPull, Jim began
collecting pieces for a double cylinder model. This one required
far more pieces, and far more work to complete, but construction
began in 1984, with final completion in 1986. The two-cylinder
model operates at 375 rpm, and has a top ground travel of 4? mph.
It weighs about 1,200 pounds.

Both OilPull models use Fairbanks-Morse 3 hp ‘ZC’
engines. Only a single engine was required for the smaller model,
with a pair of them being used in the latest design. The double
cylinder model fires 360 degrees apart, just like the original
OilPull. The cranks were cut to size and welded together using
Eutectic 680 rod. This particular alloy is very expensive, but has
the qualities needed for a weld that will be under high stress. The
single cylinder model is water cooled, but the double uses an oil
coolant, just like the original. Both models employ the Rumely
cooling system of induced draft created by the engine exhaust.
Rather than use the radiator sections of Rumely, the Patton models
have a series of vertical flues within the cooling tank.

Clutches for both models were adapted from ordinary lineshaft
clutch pulleys. Jim reworked these to include the drive shoes in a
manner virtually identical to the Rumely design. The drive train
for both models is built from the transaxles of Wheel Horse lawn
tractors, although there were probably others which could be
modified for this purpose. This eliminated the need for extensive
external gearing, and permitted the use of the higher ground speeds
required for parades. After consider able experimenting, a Schebler
carburetor was finally used on the double cylinder model. Likewise,
some experimenting was required to properly size the intake
manifolds for smooth operation.

The engine in the double cylinder was, as previously noted,
built from two Fairbanks-Morse 3 HP, ‘ZC’ engines. Setting
both cranks together for 360 degree firing created balancing
problems, so the first step was to minimize the problem by
eliminating as much sliding and swinging weight as possible. This
was achieved by the use of 35/8 inch aluminum
pistons, plus the construction of lightweight tubular connecting
rods. These are shown in Figure 1.

Figure 2 illustrates the completed single cylinder model on a
parade run, and Figure 3 shows the progress in building the double
cylinder engine. This photograph of February, 1985 indicates that
the carburetor and ignition system are installed. Subsequently
however, a Schebler carburetor was installed, and it pro vided
better results.

Figure 4 shows the double cylinder engine after the crankshaft
was installed. Even with the lightweight pistons and rods,
obtaining a good running balance was achieved by adding suitable
counterweights, and adjusting this weight through continued
experiments. The finished engine displays no appreciable vibration
at any speed from an idle up to its high idle of 375 rpm. Figure 5
illustrates the head end of the double cylinder engine after it was
installed in the chassis.

Mr. Patton failed to keep close tab on the hours of work
involved, but there is no doubt that the total figure would be
astounding. We are sure that Jim has additional projects in mind,
but our question in this regard only got a reply of ‘No
comment.’

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