How to Adjust the Valves on a Ford 9Nby Curtis Von Fange
The Ford 9N tractor was a workhorse for the small independent farmer of the 1950s. The four-cylinder motor was reliable, and repair parts, when needed, were readily available. The valve clearances, set at the factory with solid lifters, were not adjustable unless major engine machining on the valve train was required. Aftermarket adjustable lifters were offered after the tractor was discontinued and were installed in place of the solid lifters when engine work was done.
Remove the tractor hood, fuel tank, hoses and any other parts necessary to access the engine. Drain the coolant from the engine block by placing a drain pan under the block and then opening the cock valve just behind the starter. Remove the intake and exhaust manifolds and remove the cylinder head. Also remove the side panel covering the valve train that is underneath the exhaust manifold.
Rotate the engine by hand so the No. 1 cylinder is at the top of its stroke. When on top dead center the exhaust and intake valve will both be completely closed. Locate the No. 1 corresponding valve train through the side panel on the engine block. Measure the distance between the valve stem and the solid lifter on the No. 1 cylinder with a feeler gauge. If the clearance exceeds 0.012 inch intake and 0.016 inch exhaust, remove the valve and either select a longer valve for reinstallation or reface the valve and valve seat to decrease the clearance. If the clearance is less than 0.010 inch intake or 0.014 inch exhaust, select a shorter valve or remove the valve assembly and grind the lower end of the valve stem until 0.010 to 0.012 inch intake and 0.014 to 0.016 inch exhaust are established.
Rotate the engine to the top dead center point for the No. 2 cylinder and repeat the process. Repeat until all valves have been set correctly. Reassemble the motor. Close the radiator valve, refill the radiator with coolant and check for leaks.
Shut off the fuel and unscrew the fuel line running to the carburetor. Disassemble the linkage between the governor and the carburetor. Remove the intake and exhaust manifolds from the engine. Remove the side panel that covers the valve train assemblies.
Rotate the engine until the No. 1 piston is on top dead center. Align the timing marks on the vibration pulley with the raised bar on the timing cover. When properly aligned, the intake and exhaust valve stems corresponding to the No. 1 cylinder will both be relaxed, and a feeler gauge can be inserted in either valve.
Measure the distances between the valve stems and lifter. Intake valves should fall between 0.010 and 0.012 inch. Exhaust valves should measure 0.014 to 0.016 inch.
Insert the valve lifter adjusting tool onto the intake lifter. The metal extension on the tool will engage the oiling slot on the exhaust lifter and hold both lifters in place so they won't rotate as the adjusting nut on the intake is rotated. Insert the feeler gauge between the intake valve stem and the intake lifter and rotate the adjusting nut so the feeler gauge can be pulled out with very little resistance. Tighten the adjusting nut and repeat the process for the exhaust valve.
Repeat the process by rotating the engine to the top dead center for each piston and measuring the corresponding valve lifters. When finished reassemble the engine.
Things You'll Need
- Drain pan
- SAE standard socket set
- Valve lapping tools
- Bench grinder
- Valve lifter adjusting tool
- Feeler gauge
Curt Von Fange, an ASE Master Automotive Technician, began writing in 1998. His first article related a memorable experience about panning for gold with his father. It was published by "Gold Prospector Magazine" the following year. An associate degree in heavy equipment repair from Ferris State College helps him write numerous technical articles for trade magazines and webzines like YTtractors.com and Desertusa.com.