79953A04 Mercury PLUG ASSEMBLY, (.375-16 x .250) Drain

START BY:a. remove exhaust manifoldb. remove rocker shaft assembly and push rodsc. remove fuel injection nozzles **The fuel injection nozzles do not have to be removed from the cylinder head assembly when the cylinder head assembly is removed from the cylinder block. If the fuel injection nozzles are not removed, do not put the cylinder head assembly down on a flat surface. This can cause damage to the fuel injection nozzles. 1. Loosen hose clamp (2), and remove tube assembly (1) between the cylinder head assembly and the timing gear cover. 2. Remove 22 bolts (3) that hold the cylinder head assembly to the cylinder block. 3. Fasten tool (A) and a hoist to the cylinder head assembly. Remove the cylinder head assembly from the cylinder block. Weight of the cylinder head assembly is 57 kg (125 lb.).4. Remove the cylinder head gasket, water ferrule and seal from the cylinder block.Install Cylinder Head Assembly
Check the cylinder head and block for top deck flatness. The flatness of the cylinder head and block should be within 0.15 mm (.006") total, and a maximum of 0.08 mm (.003") for any 152.4 mm (6.0") span.1. Check the condition of the water ferrule and seal (4). Make a replacement if needed. Put the water ferrule and seal (4) in position with the adjusting screw of hose clamp (2) toward the top and approximately 45° to the right of vertical line as seen from the front of the engine. Make sure the seal is installed all the way into the counterbore.2. Clean the surfaces of the cylinder head assembly and the cylinder block that make contact with each other. Make sure the surfaces are clean and dry. Install a new, dry cylinder head gasket (3) on the cylinder block. If the plugs in the oil passages in the cylinder head were removed, put 5P3413 Pipe Sealant with Teflon on the threads, and install the plugs in the head.3. Fasten tool (A) and a hoist to the cylinder head assembly. Put cylinder head assembly (1) in position on the cylinder block.4. Put 5P960 Multipurpose Type Grease on the threads of all the cylinder head bolts. 5. Install the cylinder head bolts, and tighten them as follows:a. Tighten bolts 1 through 18 in the number sequence shown to a torque of 81.5 13 N m (60 10 lb.ft.).b. Tighten bolts 1 through 18 in number sequence to a torque of 149 6.5 N m (110 5 lb.ft.).c. Tighten bolts 1 through 18 again in number sequence to a torque of 149 6.5 N m (110 5 lb.ft.).d. Tighten bolts 19 through 22 in number sequence to a torque of 43.5 6.5 N m (32 5 lb.ft.). 6. Install tube assembly (5) between the cylinder head assembly and the timing gear cover. Tighten hose clamp (6).END BY:a. install fuel injection nozzlesb. install rocker shaft assembly and push rodsc. install exhaust manifoldDisassemble Cylinder Head Assembly
START BY:a. remove cylinder head assembly 1. If necessary, remove plugs (1) with a punch and hammer. 2. Fasten a hoist to the cylinder head, and put it in position on tooling (A). Use adapter plates (2) from tooling (A) to hold the head in place. 3. Put the valve springs under compression with tool (C).4. Remove the locks from the valves.5. Remove tool (C), the retainer, spring, washer and valve from the cylinder head. Put identification marks on the valve as to its location in the cylinder head. 6. Check the valve spring force with tool (B). The spring force must be 222 22 N (50 5 lb.) when the length of the spring is 42.04 mm (1.655 in.). For additional information, see Guidelines For Reusable Parts - Valve And Valve Springs Form Nos. SEBF8034 and SEBF8002.7. Do Steps 2 through 5 for the remainder of the valves. 8. Remove the valve seat inserts with tooling (D). The valve guides are part of the cylinder head. Measure the bore diameter of the guides at a location which is 19.0 mm (.75 in.) in from both ends of each valve guide. The bore must be a diameter of 9.512 0.013 mm (.3745 .0005 in.). The maximum permissible bore diameter must not be more than 9.550 mm (.3760 in.). Valve guides worn more than the maximum specification can be made to the original size by knurling. Use the 4.5" Bore V8 Dl Engine Reconditioning Procedures, Form No. SENR2031 as guide for knurling valve guides.Assemble Cylinder Head Assembly
1. Clean and remove burrs and all foreign material from the valve seat bores. 2. Lower the temperature of the valve seat inserts, and install them with tooling (A).
Do not make the diameter of the extractor [part of tooling (A)] in the valve seat insert larger when the insert is installed in the cylinder head.
3. Grind the valve inserts according to specifications given in Specifications For 3204 Industrial Engines. 4. Put clean engine oil on the valve stem. Install the valve, washer (3), spring (2) and retainer (1) in the cylinder head. 5. Put the valve spring under compression with tool (C).6. Install the locks on the valve stem with tool (B).
Make sure locks (4) are in their correct position on the valve. The locks can be thrown from the valve when tool (C) is released if the locks are not in their correct position on the valve.
7. Remove tool (C), and hit the valve with a rubber hammer to be sure the locks are in their correct position.8. Do Steps 4 through 7 for the remainder of the valves. 9. If plugs (5) were removed from the cylinder head assembly, install them with tool (D) until they are 1.0 0.5 mm (0.04 0.02) from the bottom of the chamfer.END BY:a. install cylinder head assembly