Service Procedures

SPS Joint Control System

A feature of the engine is the use of the SPS joint control system on the cylinder head bolts, crankshaft main bearing bolts and connecting rod bearing nuts and bolts. This system ensures that the joints receive maximum clamp loading for a given fixing size and type of material by tightening the fixing to its particular yield point. This greatly helps to prevent premature cylinder head gasket failures.

CAUTION: All SPS fixings must be used only once. Discard fixings on removal and replace with new bolts / nuts every time a `strip down' has been carried out.





Note: The SPS system in service requires the fixing to be set to a specific torque initially; it must then be rotated through 90 degrees exactly. The accuracy of this cannot be too highly stressed. To obtain the correct setting, use Special Tool LST 122, or a self-manufactured tool using the dimensions illustrated (Fig. 1).

Note: See Torque Tightening Specifications in the Preliminary Pages for the correct torque figures.


Sealants





One of the specified sealants for use on this engine is the Marston compound known as Hylosil 102, a white amine cure system rubber. Should this not be available an equivalent amine cure sealant must be used. Under no circumstances should any acidtoxy cure system be used. Loctite sealants are specified for certain applications. See Service Materials application table for the correct sealant for each application.