The cylinder head (Figure 2-12) is a very heavy design and made of cast gray iron. It is a 17 bolt design that has 5 bolts positioned around each cylinder, to provide a more effective seal, and improve gasket retention.
The cylinder heads for the LH6, LL4 and different model years are different. This is because of different; pre-chambers, nozzles, compression ratios, and valve sizes. Consult a G.M. Parts Book or Fiche, to determine the proper cylinder head.
Cylinder heads for 6.2L engines should be checked to verify the correct part for the application before installation on the block. The following information is provided for determining that the correct part number head has been received.
A design feature is the Ricardo Comet V precombustion chamber which has a spherical chamber which mixes the air and fuel by air swirl (Figure 2-13). This assists in promoting high turbulence. This is an ante-or divided combustion chamber, having the major chamber in the cylinder head and only a small space between the piston and the cylinder head. Close piston clearance produces high turbulence in the ante chamber and promotes rapid combustion. The charge is forced out of the throat area, agitating the entire mixture and resulting in more complete combustion. This design has a broad speed operating range. It also provides low noise and effective emission control. The pre-chamber is installed in the cylinder head flush to + .050 mm (.002 in.).
Broken Glow Plug Tip
A burned out glow plug tip may bulge then break off and drop into the pre-chamber when the glow plug is removed. When this occurs the nozzle should be removed and the broken tip removed through the nozzle hole. It may be necessary to remove the cylinder head.