Note. A new or reconditioned cylinder head can always be ordered from a car service workshop or from the warehouse of the car manufacturer's branded service center. Due to the need to use some special tools during disassembly and inspection of the head, the authors of this Guide believe that it will be easier and cheaper for an amateur mechanic to purchase a replacement head than to get involved in a rather complicated restoration repair of a worn-out one.
1. Disassembling the cylinder head requires preliminary dismantling of the valve mechanism elements (intake and exhaust valves with associated components). On SOHC engines, remove the rocker arm assemblies from the axles. Remove the camshafts with valve tappets from the heads (for details on how to check the condition of components, see Checking the condition of camshafts, valve lifters and bearings).
Caution! On SOHC engines, the removed tappets must not be turned on their sides to prevent air pockets from entering them (see section SOHC engines of this Chapter). Alternatively, the removed tappets should be placed in an oil-filled container.
2. Prepare a set of clearly marked plastic bags for organized storage of removed valve train components.
3. Using a special tool, compress the springs of the first valve and remove the crackers of the split lock of the spring plate from the groove on the rod. Carefully release the tool and remove the spring plate, springs and their seat from the valve (depending on the configuration).
Caution! Be careful not to damage the inner walls of the tappet seat when compressing the valve springs.
4. Remove the valve from the cylinder head and remove the oil deflector cap from the guide sleeve. If the valve gets stuck in the sleeve, push it back into the head and use a whetstone or a fine-tooth file to carefully clean the edges of the groove for installing the crackers.
5. Proceed in a similar manner to dismantle the remaining valve assemblies. Place the removed components of each valve in a separate bag equipped with a corresponding label - during assembly, each part must be installed strictly in its original place.
6. Once all valve train components have been removed and stored in an organized manner, you can begin the cleaning and engine condition inspection procedures (in case of a full-scale restoration repair, first complete the disassembly of the unit).
(The article was obtained from the portal: «www.NissanBook.ru»)