by Kevin Mikelonis

Foreward
Successful brand names are those that inspire passion within the heart of the American consumer. There are a number of tactics and pathways a corporation can take to touch that hard-to-reach button within each and every one of us. Ford Motor Company accomplished it in the Mustang brand with excitement and power. Mustang appeal still works for Ford today. However, the Ford brand seems to be generating little more than a resting heartbeat for the average North American car buyer.

Ford Motor Company might be facing its most significant challenge to date in their effort to re-establish the Ford brand itself in the hearts and minds of America. Most likely, Ford will employ high dollar ad campaigns that use glamour and sex appeal to sell their new models as evidenced by the Grown and Sexy ad campaign for the Ford Fusion. Although our culture and industry has changed tremendously since 1939, Henry Ford's vision of producing affordable tractors was unconventional yet brilliant. Brilliant because the decision was an indirect channel into the hearts of the American consumer. However practical we may think a tractor is, Ford brand loyalty was formed from the soil to the dinner table for many through the utility of the "N" series tractor.

About the Ford 8N
The Ford 8N was the last model produced of the "N" series tractors that were first introduced in 1939. That year, the 9N was released as an all-purpose tractor for use on small farms and included a revolutionary hitch system for pull-behind farm implements such as discs, harrows, and plows. The "Fergusen" hydraulic-controlled, Three Point Hitch system was included on the very popular "N" series tractors after a handshake deal between Henry Ford and Harry Fergusen. Prior to 1939, the Fordson Company based in England, built tractors under the direction of Henry Ford who formed his own company Ford & Sons (later shortened to Fordson). The move by Henry Ford to launch Fordson was a result of Henry's strong vision that an affordable and reliable mass-produced tractor would revolutionize farming, culture, and American life by enabling abundant crop production. The board of directors of our beloved FOMOCO did not share Henry's vision, so the independent Fordson, Inc. was born in 1917. Henry's vision proved correct and in 1939 the Ford name was applied to tractors produced in the U.S. beginning with the "N" series.

Engine Performance
The 9N (1939-41), 2N (1942-47), and 8N (1947 to 1952) tractors were all powered by Ford's 4-cylinder gasoline engines with 120 cubic inches of displacement. Early powerplants in Fordson models were also 4-cylinder designs which had 251 cubic inches producing roughly the same horsepower as the more efficient mills built into the "N" series. The trend toward efficiency in horsepower-to-displacement continues in today’s modern engines and dates back to these tractors as well.

With the release of the 8N, maximum power of the engine rose to 27.32 hp from the earlier "N" series models which claimed 23.87 hp maximum. The tractor's job on the farm was to pull hard at low speeds, so torque was the name of the game in engine design. The 8N's 1500 revs would produce 92 foot-pounds of torque which was directed through a 9-inch pressure plate type clutch assembly to a 4-speed gearbox. Capping off the 6:1 compression cylinders was an L-head which received spark from a side mounted direct-drive distributor with coil and automatic spark advance. An updraft tube carburetor fed the fuel to the motor which produced the classic sounding "putt-putt-putt-putt" that we simply have to love - no matter how big a motorhead we may be at heart.

Three Point Hitch
Each "N" series model saw improvements in engine performance, transmission, steering, and braking. The one constant in the "N" series was the technology which made the "N" series tractors easy to use and a favorite in the farming community - The Fergusen hydraulic-controlled Three Point Hitch system. Before this development all farm implements, which by nature are very heavy, were all quite different. A look at 3 plows side-by-side, all built to do the same job, would reveal different attachment points which were based on the attachment point positions on the tractors for which the implements were made, and not the job they were designed to perform. Ownership of "N" series tractors enabled neighboring farmers to share farming implements as needed rather than each farmer having to purchase individual implements that may be useless if a newer tractor were eventually purchased. The hydraulic lift arms enabled the operator to back-up to an implement and attach all three points with simple pins, then use the hydraulic arms to pick the implement up and ride out to the field where the implement was lowered hydraulically to the soil with the push of a lever. Previously, changing implements involved the help of family or friends.

	Three Point Hitch - Ford N Series Tractor
	The Fergusen Three Point Hitch system was designed to control plow depth. In this extreme example, the Farming Implement is forced to rise quickly when it contacts a rock. The reaction force is transferred along the upper link which increases the tractor's rear tire loading.

The convenience that came from the hydraulic system and the geometry of the Three Point Hitch system were great benefits for using farm implements. Looking further into the Fergusen Three Point Hitch system reveals the science of the system’s design which was used to overcome a significant soil preparation issue – plow depth. Rough soil, ruts, ditches, or quick rises in elevation create inconsistent penetration into the soil by the implement being pulled behind a tractor. A quick rise in the surface of a field that was tracked by the front tires causes the rear of the tractor, which carries the implement, to dig deeper into the ground. The opposite effect occurs when the front of the tractor followed the ground’s contour down into a rain washed rut in the soil, leaving unplowed soil.

The Three Point Hitch system is made up of two lower trailing arms which are attached to the tractor’s frame and pull the implement along, and the third point is a spring loaded upper-link attached to the center of the tractor. Racecar chassis builders may begin to recognize the setup described here. The forces generated when dragging an implement into the soil are referred to as draft. The draft force increases as the implement digs deeper, and decreases as the implement runs more shallow in the soil. In the Fergusen system, after the operator sets the initial depth of the implement using the lever, these draft forces are measured and used to signal the hydraulic system to raise or lower the implement automatically. The spring loaded upper link helps push the implement into the ground, increasing resistance, adding weight, and giving the tractor more traction on loose soil.

	Typical Three Point Link System - Stock Car
	Reaction forces and weight transfer experienced during rapid deceleration in stock car racing force the pinion angle of the differential downward. The Three Point Link System transfers the downward pinion angle into lift on the Forward Pivot Point. Lift on the Forward Pivot Point results in greater tire loading. For increased control of these forces a spring is used on the upper link to regulate the rate at which the forces occur.

Traction in any vehicle is all about weight transfer. Race chassis science focuses on all the principles involved in weight transfer for actions such as acceleration, braking, entry to and exit from a turn. Based on the type of racing a given chassis is designed for, the forces which regulate some of the actions are given more consideration than others. The same principles which are used to put more weight on the rear tires of a tractor using a spring loaded upper-link for a farming implement are also used to increase weight on the rear tires of a dragster, or produce forward bite in a circle track car while under braking or deceleration. Amazing that such principles used at 1500 revs 80 years ago, are still at work today in vehicles spinning 8,000 rpm’s at hundreds of miles an hour.

The upper link from the top center of the plow implement is pinned to a spring loaded perch which helps apply force to keep the implement in the soil. With the implement on the ground, the pin is removed along with the lower link pins for quick change to other standardized implements.		This lower left trailing arm is connected to the side of the 8N’s differential. An identical assembly on the opposite side combines to pull the implement through the soil. The vertical rod which straddles this trailing arm is used on the opposite side to raise and lower the implement with a hydraulic ram.
Standing at the rear of the implement and looking through the center of the 8N’s differential, the upper link is notably offset. The Three Point hitch assembly allows for this side to side movement on the implement which is not critical. When the same three-point assembly is used for locating a differential on a race chassis, a Panhard Bar or J-Bar is used to keep the differential’s track in place.		The outside view of the right side lower trailing arm illustrates the overall length of the arm and both the mounting position on the 8N’s differential and the implement.
The entire Three Point hitch assembly is shown in position on the ground. When in use, the implement will be 2–8 inches beneath the soil surface. The upper link and lower training arms will take on a slope toward the ground at that point and the draft forces are used to signal the hydraulic system to adjust and maintain a consistent depth into the soil.

Conclusion
Ford N-Series tractors still operate today as worthwhile workhorses on small farms and properties all over the United States. The tractors are also celebrated in small town parades and fairs as a testament to America's agri-centric past. To find out more about the Ford N-series tractor, visit the Ford 8N-9N-2N Tractor Club at the Yesterday's Tractor Company website. If you have any questions or comments regarding this article feel free to email the author, Kevin Mikelonis.