5-101.bk Page 27 Friday, March 17, 2006 11:05 AM 1 2 When the deck is resurfaced, fire ring groove and valve seat insert dimensions must be reestablished. Correct dimensions are shown in this section. 3 4 5 [213 EH] Fire Ring Groove 6 DESCRIPTION Figure 5-27 — Valve Assembly 200483a Fire ring grooves are located in the machined flat surface of the cylinder head that mates with the engine block. These grooves correspond with the fire ring machined lip on cylinder liner. This design provides a locking groove for the fire ring to seat as well as a positive-combustion pressure seal.
[213 EX] Cylinder Head Inspection After resurfacing the cylinder head deck, it is necessary to reestablish the fire ring groove depth using fire ring groove cutter J 29600-C. Pressure Test — It is recommended that cylinder heads be pressurized and checked for internal cracks and leaks. Refer to Cylinder Head and Cylinder Block Leak Test procedures in the TROUBLESHOOTING section of this manual. 1 Check cylinder head deck surface for warping, pitting or other imperfections. Deck surface flatness for a new head must not vary more than 0.0015 inch (0.0381 mm) over 18 inches (45.7 cm) of surface area. Resurface or replace as necessary.
2 When resurfacing, remove a minimum amount of material from deck to obtain a flat, uniform surface. Standard head height is 6.397–6.391 inches (162.483–162.310 mm). A maximum of 0.010 inch (0.254 mm) of material may be removed, making the minimum height of a resurfaced head 6.381 inches (162.077 mm). 8 3 7 5 6 4 Figure 5-28 — Fire Ring Groove Cutter J 29600-C 200287a Page 5-27 200 BENCH PROCEDURES 1. Valve spring keepers 2. Upper washer 3. Valve spring 4. Oil seal 5. Lower washer (Roto-Coil) 6. Valve 1. Alignment fixture 2. Hold-down capscrews 3. Spacers 4. Washers 5. Cutter head (J 37719) 6. Wing nuts 7. Thickness gauges 8. Cutter base