Genuine 1988 Chevrolet Nova Cylinder Head

1988 Chevrolet Nova Parts Questions & Experts Answers

• Q: How Should the Cylinder Head and Pistons Be Decarbonized and Inspected on 1988 Chevrolet Nova?

  A: Decarbonizing can be performed with the engine either in or out of the car. With the cylinder head removed, carefully eliminate all carbon deposits from the combustion spaces and ports using a blunt scraper or wire brush, ensuring the valve head stems and guides are also cleared. Clean the combustion areas and ports with solvent, and scrape the cylinder head surface free of any foreign matter. If the pistons remain in the block, take care to prevent carbon from entering the cylinder bores to avoid scratching the walls or damaging the piston and rings; turn the crankshaft to position two pistons at the top, stuff rags into the other bores, and cover the waterways with masking tape. Apply a little grease between the cylinder walls and the two pistons being worked on, then carefully scrape the carbon from the piston crown and surrounding cylinder wall lip, ensuring not to scratch the aluminum. After removing all carbon, clean away the contaminated grease without pushing any into the bores, then rotate the crankshaft to position the next two pistons at the top and repeat the process until all cylinders are decarbonized. Inspect the cylinder head for cracks in the exhaust ports and combustion chambers, as well as external cracks into the water chambers. Check the head gasket mating surface for warpage using a straightedge and feeler gauge; if warpage exceeds the specified limit, resurfacing is necessary. Examine the rocker arm studs for wear and damage, and for big-block VB cylinder heads, inspect the pushrod guides as well. For big-block VB and some high-performance small-block VB heads, the pushrod guides are secured by nuts on the rocker arm studs, which can be unscrewed for guide replacement; coat the replacement stud with gasket sealant and torque tighten. In small-block VB engines, the studs are pressed in, and replacement requires specialist operations involving reaming the stud holes slightly oversize, lubricating the new studs with hypoid axle oil, and pressing them in to their original depth.