Chevrolet 12360333 Cylinder Head Kit

That part of the head where the exhaust ports and chambers are located should be checked for signs of externally visible cracks, while the water chamber also should be checked for similar signs. Check the valve stem-to-bore clearance by measuring the diameter of the valve stem in three places: On the material, measurements across the width were taken from the top, middle and bottom layer and by using a micrometer or dial caliper. Taper type exhaust valves have their stems threaded about 0.001-inch larger on top end than at head. Place a hole gauge in the over head valve guide bore so as to get the bore diameter which in turn enables one to determine the valve clearance. If the clearance is greater than the specified limit an oversize valve must be used and ideally the valve guide bore should be reamed, this is always best left to a dealer or machine shop. Clearence when taken in extreme impacts the oil consumption if it is taken very high and the noises and sticking of valves when it is taken low. Another method used in confirming clearance is to install a valve with the head slightly off the seat, then connect a dial indicator to the valve head, open and close the valve and record the movement of the dial from which the actual clearance is arrived at by dividing the record by two. Check each valve spring available and its damper checking for deformation, crack or broken parts and replace with a new one. To check the check valve spring tension use GM tool J-8056, by measuring the height at which the springs are compressed the tension without the dampers; if it is not within 10 lb of the specified load, then replace the spring. Rocker arm studs must be checked for signs of wear and damage by removing them by using deep socket, while new ones must be put on gasket sealant before being tighten to the required torque value. Shell pushes should be examined for warping, by rolling each of them on a piece of clean glass; a pushrod found to be twisted or damaged in any way should be replaced. Dimensions and positions of cylinder head must also be checked: Place a straightline along the length of the cylinder head and check the feeler gauge across the three positions of the head gasket surface and across the diagonals. If with a straightedge touching end to end, warpage is greater than .006-inch, the cylinder head should be machined; if warpage is greater than .003 inch when a 6 inch straightedge is laid across the entire head, the head should be resurfaced. Boring is a job for an automotive machine and remember that resurfacing the cylinder head will change its position with relation to the intake manifold and therefore the manifold should be resurfaced in proportion.

Check that all subassemblies of the valve mechanism are cleaned and dematted, and that the bare cylinder head is free of carbon and dirt itself and also reamed or ground for valves. Place a valve in the correct port and install the valve spring set of that cylinder comprising of the spring, damper, shield as well as the cap. Place the valve spring compressor of the assembly over the valve stem and compress it. It is worth to insert a new oil seal with the flat side downwards, and it must not be twisted. Next is to put the valve locks and release the compressor and ensure that the lock rests well on the upper part of the valve stem. Measure the installed height of the valve springs with a narrow, thin scale; measure from the top of the shim or spring seat to the top of the valve spring or spring shield. If needed, place up to 1/16 th inch thick shim under the valve spring to build the required thickness; nevertheless, do not shim down to a height that is thinner than the specified minimum length of the spring; if this happens, get a new spring. Last of all, inspect each of the twenty stems for oil leaks using a vacuum test simply because if the seal is installed correctly, it should not cause any vacuum leakage.

If the engine has been removed from the car, disregard the following steps which do not apply. First, remove the intake manifold, followed by the exhaust manifolds. Next, take off the upper generator bracket and stud, and then remove the dipstick tube bracket from the left cylinder head. Loosen the rocker arm nuts enough to pivot the rocker arms away from the pushrods, and then remove the pushrods, ensuring that all valve mechanism components are kept separate for reinstallation in their original positions. Loosen each of the cylinder head mounting bolts gradually until they can be removed, noting the length of each bolt to assist with installation. Lift the heads free of the engine, possibly with the help of an assistant, and if the head is stuck to the engine block, avoid prying it free to prevent damage to the sealing surfaces; instead, use a hammer and a block of wood, tapping upward at each end. Finally, remove the cylinder head gaskets and place the heads on wood blocks to prevent damage.

Install a new oil seal in the lower groove of the valve stem, ensuring it is flat and not twisted.

Remove the oil seals from the stem of each valve, using new seals upon reassembly, and take out any spring shims used at the bottom of the valve spring.

Next, take off the upper generator bracket and stud, and then remove the dipstick tube bracket from the left cylinder head.

A buffing wheel should be employed to eliminate all carbon deposits from the valves, ensuring the order of the valves is not mixed up during cleaning.

Loosen each of the 10 cylinder head mounting bolts one turn at a time until they can be removed, noting the length and position of each bolt for reinstallation.

After cylinder head installation, you should reassemble the remaining components in reverse order, including the rocker arm cover, rocker shaft assembly, pushrods, and any components that were removed earlier.

Note that resurfacing the cylinder head will slightly alter the intake manifold position, requiring proportional resurfacing of the manifold.

Place the gasket over the engine block dowel pins and carefully lower the cylinder head onto the engine, ensuring the gasket remains in place.

Finally, remove each valve in turn and place them in the numbered box or rack to complete the valve mechanism removal, ensuring that the valve components are kept in an area where they will not be mixed up.

If the engine has been removed from the car, disregard the following steps which do not apply.

Begin by removing the intake manifold and the exhaust manifolds. Next, remove the lower mounting bolt for the alternator and set the alternator aside while removing the lower bracket.

Thoroughly clean the threads on all cylinder head attaching bolts.

Clean all carbon from the combustion chambers and valve ports using GM tool J-8089 or a similar cleaning attachment available at auto parts stores, which connects to a common hand drill motor.

Proceed to remove the pushrods and detach the thermostat housing from the cylinder head. Remove all vacuum valves and switches from the cylinder head, followed by the engine lifting "eyes" and the A/C compressor mounting bracket.

Keep them separate and in order for re-installation, using a numbered rack or cardboard with holes.

Ensure all valve mechanism components are clean and free from carbon and dirt, and that the bare cylinder head is also clean and devoid of any abrasive agents used for valve grinding or reaming.

It is important to label and store the valves and their components to ensure they can be reinstalled in the same valve guides. Additionally, measuring the valve spring installed height and comparing it to the specifications is crucial; if the height exceeds the specified limit, the valve seats and faces will require attention.

Regardless of whether the head was sent to an automotive machine shop for valve servicing, ensure it is clean before beginning reassembly.

Exhaust valves have tapered stems, which are approximately .001 inches larger at the top than at the head end.

Install each bolt finger-tight without tightening them at this stage.

It may be wise to consider relevant information before making a decision regarding the overhaul process.

Refill the engine with coolant, start the engine, and check for leaks. After warming up the engine, recheck the cylinder head bolt torque.

Disconnect the exhaust pipe from the exhaust manifold and remove the oil dipstick tube assembly from the engine side.

Exhaust valves have tapered stems, which are approximately .001 inches larger at the top than at the head end.

Ensure the threads of the attaching bolts and the threaded holes in the engine block are free of dirt by running a tap through these holes.

Use parts cleaner to remove all sludge and dirt from the rocker arms, rocker balls, pushrods, and valve springs, working on one set of components at a time and returning each set to its numbered location on your box or rack.

Remove the oil seals from the stem of each valve, using new seals upon reassembly, and take out any spring shims used at the bottom of the valve spring.

If no excessively worn parts are found and the valve faces and seats are in good condition, the valve train components can be reinstalled without major servicing.

Remove the lower alternator mounting bolt from the right-side cylinder head.

Install the valve locks and release the compressor, confirming that the lock seats properly in the upper groove of the valve stem.

Finally, lift the head free of the engine, using a hammer and block of wood if it is stuck, and remove the old cylinder head gasket.

Lift the head off the engine, using a hammer and block of wood to tap the head if it is stuck, and place it on a block of wood to prevent damage to the gasket surface.

Thoroughly clean the gasket surfaces on both the cylinder heads and the engine block without scratching or damaging these sealing areas.