Part 5 The Cooling System cont.

Now we will consider the brackets. The main one that locates the top of the radiator to the body of the car and also contains the mountings for the two (air-con) fans is still available from Unipart under P/No. PKC249 at £23.50. The lower bracket, which holds the bottom of the radiator in place and also locates the lower end of the fan mountings, part number RKC3112, is now NLS. However all is not lost, Rimmers sell the re-manufactured equivalent UK spec bracket P/No. RKC532 which will fit with some modifications. The major difference between the UK and Air-Con spec brackets is a variation in height of approximately 1", therefore it will be necessary to cut 1" out of the vertical side frames and re-weld. Great care should be taken when carrying out this modification as this bracket holds up the radiator and mates with the fan bracket, so the actual dimension should be deter- mined with some accuracy. The bottom of the fan bracket is attached to the lower bracket via two weld nuts. The correct position of these will be established when the radiator assembly is bolted in place on the vehicle. A bonus from using this fan bracket is that the mountings for the coil and the Ballast Resistor are already in place. (NB: Unfortunately, Rimmer Bros radiator CANNOT be used as it is 1/2" deeper.)

Next, the electric fans - again these are no longer available from Unipart, but the ones found in the Austin Allegro have proved to be a suitable alternative, having only a slightly smaller diameter on the blades but a similar mounting arrangement. To mount them in the fan mounting bracket, it is necessary to fit a carrier plate over the existing mounting holes and re-drill new holes as required to accept the new fan studs. Once this has been done the fans should be tested, not only for correct operation, but also for correct rotation. Air should be sucked through the radiator and over the engine. If this is not happening, reverse the wires on the fans +ve to -ve. Finally, before fitting the fan bracket and radiator together, a length of rubber sealing should be fitted round each fan cage, again not now available, but the sealing rubber from the boot surround is very similar and can be used. This obviously makes a seal between the fan and the radiator so that all the air must be drawn through the radiator. The complete assembly can now be bolted in place (not forgetting the top and bottom radiator mounting rubbers).

Finally, the wiring of the fans. As I am no automotive electrician, I left this to a friend who is qualified in this field. This ensured that a good safe system was devised with fuses in the circuit and the correct sized wire used. Remember, a bodge job can be easily done, but if the wiring is overloaded then not only the fan circuit but also the whole car could catch fire. The system is in two parts, each running a separate fan. Fan no.1 fitted to the left side of the radiator operates automatically via the temperature sensor on the radiator. (NB This fan will run on after the engine is switched off to assist cooling and help combat fuel vapourisation that sometimes occurs after a prolonged run and quick restart on the V8). Fan no.2 operates manually from a spare switch on the dashboard switch panel (a headlight or footlight switch could be used as these include a warning light, this enables the second fan to be employed only if the engine temperature becomes too high whilst idling or in heavy slow moving traffic - I would not expect this fan to be used under normal circumstances, but it should be exercised from time to time. Regarding the relays (Lucas type 28RA or equivalent), these should be mounted near the fans but in a position where they can be easily maintained - on the TR8 they were fitted to the LH head- light mounting bolts.

The wiring diagram on the next page is, I think self-explanatory but if there are any doubts consult a qualified electrician. One additional safeguard I employed with this system was to make up a spare link wire to join the two terminals on the radiator sensor in the event of a failure of this item. The fan may then be on permanently but it will get you home!!