GASKET 8N4524 - Caterpillar

Caterpillar Products Machine Engines All 3500 SeriesService Magazine, SEPD0746, 16, August 2004, "New Cylinder Head Groups and Valve Mechanisms". Disregard this article. The 239-0690 Cylinder Head Gp has been removed and the 335-6218 Cylinder Head Gp has been added for the MUI Engines.Description Of Change: New cylinder head groups and assemblies are available for all 3500 and 3500B Engines. The new head groups and assemblies include a new exhaust valve with a larger stem diameter and an exhaust valve guide with a larger inside diameter. The larger stem diameter reduces stress in the valve stem during severe engine operation. The new groups also include floating valve bridges that eliminate the need for bridge adjustments. The new groups also include the following new components: valve springs, rotators, spring washers, and valve stem seals.Adaptable To: Use the new basic cylinder head groups for Top End overhauls and for Major overhauls on all 3500 and 3500B Engines. The new basic cylinder head groups may be used individually in replacement of the former basic cylinder head groups.The former cylinder head groups and the new cylinder head groups are listed in Table 1.
Table 1
Cylinder Head Group Former Basic Cylinder Head Group New Basic Cylinder Head Group
3500 Engine with EUI
7E-8758 Cylinder Head Gp 239-0691 Cylinder Head Gp 335-6219 Cylinder Head Gp
3500 MUI Engine
4W-0095 Cylinder Head Gp 172-0835 Cylinder Head Gp 335-6218 Cylinder Head Gp
3500B Engine
101-0830 Cylinder Head Gp 201-4257 Cylinder Head Gp 335-6220 Cylinder Head Gp Use the new individual parts for replacement of any former individual parts. If any of the new parts are installed, all the former parts on that side of the cylinder head must be replaced with the new parts. For example, if one inlet valve spring is replaced with the corresponding new spring, then all the springs on both inlet valves, both of the seals, and both of the valve rotators must be replaced with the new part numbers. The former parts and the new parts of the basic cylinder head groups are listed in Table 2.
Table 2
Former Part New Part
133-9306 Valve Guide (Inlet)
197-6995 Valve Guide (Exhaust)
468-8824 Inlet Valve
443-2712 Exhaust Valve 468-8825 Exhaust Valve
197-7006 Seal 316-5980 Valve Stem Seal
209-0962 Washer 316-5981 Washer
194-4901 Outer Spring 316-5976 Outer Spring
194-4902 Inner Spring 316-5977 Inner Spring
197-7062 Rotocoil Assembly (Inlet) 316-5978 Rotocoil Assembly (Inlet)
197-7063 Rotocoil Assembly (Exhaust) 316-5979 Rotocoil Assembly (Exhaust)
2A-4429 Retainer Lock (Inlet)
197-7055 Retainer Lock (Exhaust)
8T-6759 Pipe Plug 8T-6759 Pipe Plug
7N-1902 Dowel 239-0689 Dowel(1)
265-7537 Bridge Assembly (Inlet)
265-7538 Bridge Assembly (Exhaust)
(1) Only required on 3500 MUIThe bridge dowels must be removed and/or a bridge dowel must be modified when a cylinder head that originally had adjustable bridges is rebuilt.Because of the design of the floating bridge, the cylinder head for a 3500 Engine with EUI and for a 3500B Engine does not require any dowels.Because force is placed on the fuel injector by the rack, the cylinder head for a 3500 MUI Engine requires one 239-0689 Dowel to maintain correct