Ford 9S4Z-6507-C
Intake Valve

The examination of the valve must include inspection of the stem end for grooves or scoring together with assessment of the valve face and edge for pits, grooves, or scores and evaluation of the valve head for burning indications, erosion, warpage, and cracking and checking of the valve margin for wear.

The first step of valve repair begins with measuring both valve stems from specific points then checking if their diameters meet manufacturing standards. The service requires installing new components whenever any valve stem diameter shows non-compliant specifications. Perform a comprehensive examination of all valve areas starting from the stem tip where grooves and scoring should be assessed before checking the face and edge region for pits and scores along with the valve head for burning damage and deformation and cracking while investigating the valve margin for wear.

The first step to check the valve clearance includes taking out the valve cover. Employees should turn the engine clockwise while using the crankshaft bolt. Prior to removing the camshafts measure the base circle clearance of each valve pointing away from the tappet because lack of this step will result in wasted labor time due to repeated installation and removal processes. Measuring valve clearances requires a feeler gauge to set readings for each valve. A good valve clearance measurement for intake valves should be between 0.008 and 0.011 inches (0.22 to 0.28 mm) while exhaust valve clearance should be between 0.010 and 0.013 inches (0.27 to 0.33 mm). When choosing tappets apply this formula: measure the tappet thickness by adding clearance to base tappet thickness after subtracting the most suitable tappet amount. Both the installation area for pre-chosen tappets needs to be marked. New tappets need installation in the areas where measurement results fall outside the specifications.

Service and repair of the valve starts by unbolting the valve cover and accessory drive belt splash shield as well as the two bolts before measuring each valve clearance at the base circle with the lobe away from the tappet. Properly tighten all bolts to 9 Nm (80 lb-in) after reinstallation. Wrench the engine clockwise using only the crankshaft bolt to measure each base circle clearance with the lobe facing the tappet before removing the camshafts because this step will lead to repeated installation which wastes labor time. Near the crankshaft bolt torques reach 9 Nm (80 lb-in) while measuring the feeler gauge data of each valve clearance point by point. A tappet with the mark 0.650 indicates a physical thickness of 3.650 millimeters because the decimal digits in the notation symbolize the total number size. The standard desired operating clearance for intake valves should be 0.25 mm (0.0095 in) while exhaust valves require 0.30 mm (0.0115 in) clearance. Measure tappet thickness by adding base tappet thickness with the measured clearance then subtracting the most desirable thickness measurement. The installation of new valves should result in clearances measuring between 0.22-0.28 mm (0.008-0.011 in) for intakes and 0.27-0.33 mm (0.010-0.013 in) for exhausts. Install the tappet which most closely matches the required size and identify its correct place for installation. The procedure requires replacement of new tappets at positions where existing tappets fail to match the inspection standards.

The repair and servicing process starts with measurement of the specified points on each valve stem diameter which must fall within the required specifications. The valve will need new components if its diameter measurement exceeds required specifications.

Services and repairs on the valve require measuring valve stems of each intake and exhaust at specified locations to confirm dimensions stay within mandated values.

Inspect the valve areas, including the end of the stem for grooves or scoring, the valve face and edge for pits, grooves, or scores, the valve head for signs of burning, erosion, warpage, and cracking, and the valve margin for wear.

Recheck the installed length of the valve springs after grinding the seats, shimming them as needed to achieve the correct installed spring length.