Nissan 11040-85E01 Cylinder Head

The cylinder heads as well as other components that are relevant to the valve train must be cleaned and then examined to determine the required valve service work in the process of overhauling the engine. Remove all the remnants of the old gasket material and any sealing compound off the cylinder head gasket, intake manifold, and exhaust manifold surfaces avoiding damaging the cylinder head. Scrape off the deposit from the coolant passages and scrub the numerous holes with a brass bristle. Insert an appropriate-size tap into each threaded hole to counter-bore the corrosion and thread sealant and use compressed air to blow dirt wearing goggles. Scrub the combustion chambers with a brass wire brush and solvent if carbon has settled and wash the cylinder head with solvent and dry it with an air compressor. Lubricate 280 rocker arms and shafts using solvent provided and it is important not to confuse the left and right units, and same with all the valve springs, spring seats, valve stem locks and retainers always do them one at a time. Clean a heavy deposits on the valves by scraping and for the head and stems use a motorized form wire brush that maintains and organizes the valves. Check the heads for cracks, leaks and other major or minor defects, advise the automotive machine shop if needed. Ensure that the cylinder head gasket mating surface is flat by placing a straightedge, in combination with a feeler gauge and observe the valve seats for signs of pitting, cracking or signs of burning. Gauge valve stem to guide clearance with a small hole gauge and take micrometer readings to the guide to ensure that it is not worn out. Visually check all the valve faces to verify if there are signs of wear, deformation or cracks, and check the margin width of each valve and replace those that do not conform to set standards. Inspect check valve springs for wear etc for free length check to see that it is suitable for reuse and inspect spring retainers, valve stem locks for wear and crack etc and replace any suspected parts. If there are scars or excessive wear them, they have to be replaced, and if the valve elements are worn, disassemble the valves in the cylinder head for further service suggestions.

Install the valves with light oiling on the stems into the valve guides. Install the valve spring seat(s) in place on the cylinder head. For SOHC engines, install the outer valve spring seat first, then the inner valve spring seat second. After positioning the valve spring seat(s) correctly, install the valve seals over the top of the valve tips by hand, using the stem of the valves as a guide. To install the oil seals firmly over the guides, use a seal installation tool or an appropriate-size deep socket, gently tapping each seal into place until it is properly seated.

Next, install the camshafts.