The home of the UK's greatest sportscar
07/02/2009
Racing Green TVR are pleased to announce that the full Simplex timing chain and halftime bearing upgrade will be available this month. Major modifications include the complete redesign of the halftime sprocket and supporting shaft. Following these significant design developments the complete Simplex timing chain upgrade is now in production and will be supplied as a complete kit of new parts including all sprockets, timing chains and pressure fed needle roller half time bearings. The original halftime bearing design is vulnerable to problems, largely due to the loads applied to the 2 ball bearing races and the lack of a dedicated oil feed. Having studied and tested uprated bearings in this application Racing Green TVR felt the best approach was to replace the ball bearing races with a twin needle roller bearing design. There are many benefits to needle roller races including a massive increase in load capabilities. The use of needle roller bearings also allows the design of the halftime sprocket to benefit from a single bore created in one machining operation ensuring absolute accuracy of bearing location.
The halftime shaft is a complete new design with internal oil feed to both needle roller bearings. The shaft diameter is increased and both the quality and hardness of the shaft is increased. The oil supply to feed the shaft and bearings is taken from the end of the oil gallery and fed direct to the shaft where it feeds the bearings via internal drillings.