Part 5 The Cooling System

This is another job that can be completed, off the car, before the major part of the conversion and a trial fit carried out by only removing the TR7 radiator. As the TR7 was originally designed to incorporate the Rover.V8 engine, the conversion of the cooling system to V8 spec is basically a nut and bolt exercise. However, as some of the original TR8 parts are no longer available, it is often necessary to modify existing parts.

Originally the TR8 was fitted with two alternative cooling systems: 1) Non Air Con type - which incorporated a fan and viscous coupling fitted to the crank-shaft pulley, or, 2) Air Con type - which incorporated twin electric fans on a framework between the radiator and engine. In both cases, the original radiators are no longer available. Similarly the viscous fan mounting cone and the electric fans are now NLS at Unipart. However all the leading Triumph suppliers can offer a re-manufactured version of the Non Air Con type bracketry. This will enable the radiator to be fitted to the car in the correct position but without the benefit of the forced cooling system offered by BL This is the simplest method and Rimmers now offer a complete kit for this application. The radiator, although offered to TR8 specification, is approximately 1/2" deeper than the original but does not cause a problem in this application. Regarding the viscous fan arrangement, this again is available from Rimmers, with the exception of the crankshaft extension drive ERC1519. However, I have managed to find someone who is prepared to re-manufacture this part for about £50. Therefore, the original TR8 system can be incorporated into the conversion. As an alternative, the usual Kenlowe fan kit can be mounted on the front of the radiator, but make sure it is rotating in the correct direction - air should be drawn in from the front of the car and blown over the engine.As an alternative I would like to suggest a method that I have used for mounting the radiator, and the fitting of electric fans and ancillaries.

First the radiator itself. The early FHC's up to VIN200000 were fitted with radiators having the top hose exiting from the left side when viewed from the driver's seat and the bottom hose exiting from the light side. This, of course, is the same configuration as the TR8, but the hose diameters are different. To overcome this I contacted my local radiator repair specialist. First we looked at the comparative flow rates of the TR7 and TR8 radiator-S, there was only a small difference. Next the diameters of the TR8 (SD1) hoses were compared with the TR7, again bearing in mind a reasonable safety factor built into the radiator it was decided that the TR7 outlets could be sleeved without causing an unacceptable restriction to the flow. Initially we had thought of unsoldering the existing outlets, but by fitting larger ones it was felt that the strength of the side tanks would be locally reduced, so the correct diameter sleeves were fitted. At the same time the radiator should be fitted with a new core to ensure there are no restrictions. We found that the TR7 Aircon 3 row supergill core with 14 fins/inch to be quite adequate. The next stage was to fit a threaded boss to the left hand top side of the radiator to enable a TR8 type temperature sensor to be fitted, the original is still available under TKC5532 but I have found that its temperature range was incorrect so I bought an after-market sensor with a range of 82-92'C. These are freely available and fit, a standard sensor boss. The assembly was then pressure tested prior to fitting to the car. Price wise, fitting the radiator with a new core and carrying out the mods cost approximately £130 and the sensor £11 - not bad for peace of mind!

The partial flow tank causes no problems as, again, the tank and bracket fitted prior to VIN200000 were on the same side as the TR8 configuration. Although not now available from BL, a little diligent searching in a scrap yard produced the goods. It is only necessary to drill three holes in the correct position in the right hand inner wing and bolt the assembly in place. If the correct tank and mounting bracket cannot be located then the existing one can be used but the mounting bracket will not sit squarely The hose from the tank to the radiator is a little more difficult, but Henry Ford came to the rescue with a suitably sized water hose incorporating a 900 bend. The final job is to move the low water level warning wire to the tank from the left wing to the right one.