GM 12360424 Engine Cylinder Head (W/Valve)

Take great care to see that the engine cools completely before you loosen the cylinder head bolts. In case of vehicles with a high mileage and during overhaul of an engine, it is preferable to check camshaft lobe heights before removing the cylinder heads. This will involve relieving fuel pressure, disconnecting the negative battery terminal, and removal of alternator and brackets, intake manifold, exhaust manifold, drivebelt tensioner bracket and power steering pump (if equipped). Also disconnect wires, hoses, fuel and vacuum lines from the cylinder head and label them for reinstallation. Disconnect spark plug wires then remove spark plugs. Take off rocker arm cover-rockers and pushrods. With a new head gasket; outline cylinders as well as bolt pattern on cardboard while loosening each cylinder head mounting bolt 1/4 turn at a time storing in cardboard holder. Carefully lift off the head tapping if it sticks onto a block of wood. Remove the Cylinder Head Gasket. For installation purposes; transfer external parts to the new cylinder head if needed , clean gasket surfaces , ensure clean threads on head bolts and engine block , apply gasket sealant to the new gasket (1987-1989 models)lower the cylinder head onto the engine then install bolts finger tight .Gradually tighten each bolt in 1/4 turn increments in recommended sequence to reach specified torque .While tightening mark each one in order to keep track of sequence used.Complete all remaining installation steps including refilling cooling system and changing oil filter.

New and rebuilts cylinder heads for GM engines are usually offered at dealers and auto parts stores for replacement practical and feasible for home mechanics to get the replacement heads and install since specialized tools are required for dismantling the heads for inspection and replacement parts may not be available. That said, if one goes for buying complete cylinder heads or overhauling the complete engines at one go, then the cylinder heads can be sent to a professional automotive machine shop or a GM dealership for the process of overhaul. In case the decision to over haul the cylinder heads is made, one needs to know what is involved in the process; the tools required, and cylinder head replacement parts. To start, utilize a valve spring compressor to compress each valve spring and get rid of the valve locking keys and do it one valve in a time. Following the removal of the keys, one pulls the spring and then removes the spring cap, spring shield (if used), spring, and the spring damper and placing these together in a number box or rack utilized when removing the cylinder head in order to organize all valve mechanism parts separately for reassembly. Subsequently, it is also necessary to unscrew the oil seals with reference to the stem of each valve but with the installation of new ones every time therefore if there are any spring shims situated at the bottom of the valve spring should also be removed. Last of all, the valves are all unscrewed one at a time and put one by one in the numbered box or put them on the numbered rack to end the valve mechanism removal while make sure that the valve component will not be placed with the valve component of other valves.

The valve mechanism elements must be clean from carbon and dirt I the same way that the bare cylinder head must be clean to the extent that there is no trace of any abrasive agents used in the grinding or reaming of the valves. Place a valve into the proper port and on the Oldsmobile engines compress a new seal over the valve stem and down into the head. Prepare the valve spring assembly for that cylinder; then clamp the assembly over the valve stem by means of a valve spring compressor. For engines of Chevrolet, replace the oil seal, placing it in the lower groove of the valve stem, and make certain that it does not twist. Last turn the valve locks and turn off the compressor until the lock sits in the upper slot of the valve stem.

The first step is to disconnect the negative battery cable.

The valve stem-to-guide clearance should be measured.

Lift the head off the engine, using caution if resistance is encountered, and place the head on blocks of wood to protect the gasket sealing surfaces.

After removing the valves and their related components and storing them separately, the cylinder head should be thoroughly cleaned and inspected. If a complete engine overhaul is being done, it's recommended to finish the engine disassembly procedures before beginning the cylinder head cleaning and inspection process.

Check the installed valve spring height with a ruler graduated in 1/32-inch increments or a dial caliper. If the head was sent out for service work, the installed height should be correct. The measurement is taken from the top of each spring seat, rotator, or top shim to the bottom of the retainer. If the height is greater than specified, shims can be added under the springs to correct it. However, do not shim the springs to the point where the installed height is less than specified.

The initial steps to remove the cylinder head are to disconnect the negative battery cable and drain the cooling system.

Loosen the cylinder head bolts in 1/4-turn increments.