Rocker-arm geometry generates a side force, tilting the valves outward and wearing away the upper and lower ends of the guides. The loss of a…
Aluminum heads usually carry the camshaft and are often mounted to a cast-iron block. The marriage is barely compatible. Aluminum has a thermal coefficient of…
Figure 7-25 illustrates a Detroit Diesel cylinder head, partially dressed out for pressure testing. At this point, most shops would introduce high-pressure water into the…
Assuming that both ends of the crack are visible, it is normally possible to salvage an iron head by gas welding. For best results, the…
Cylinder heads should be crack tested before and after resurfacing. The apparatus used for ferrous parts generates a powerful magnetic field that passes through the…
Minor surface flaws and moderate distortion can usually be corrected by resurfacing, or “milling.” However, there are limits to how much metal can be safely…
Make a careful examination of the parting surfaces on both the head and block, looking for fret marks, highly polished areas, erosion around water-jacket ports,…
Cleaning techniques depend on the available facilities. In the field, cleanup usually consists of washing the parts in kerosene or diesel fuel. Gasket fragments can…
Head bolts should now be accessible, but not always visible. Olds 350 engines hide three of the bolts under pipe plugs (Fig. 7-15); some Japanese…
Disengage the drive chain or belt (Fig. 7-14). Camshaft mounting provisions vary; some ride in split bearings and are lifted vertically, others slip into full-circle…