It is clear from the experiences of various club members that our cars can overheat in lengthy traffic jams in hot weather and if they are driven for long periods of time at speeds in excess of 65-70mph. These problems are much worse in hotter countries than the UK and result in massive water consumption. Some Australian owners have even removed their radiators several times in long journeys believing that they must be faulty! 

To overcome overheating and water loss, several companies have fitted modified radiators with increased cooling efficiency and pressurised the cooling system, using a catch tank from a more modern vehicle. On the face of it, this would seem perfectly acceptable since the later military versions of the B60 received similar treatment with success. 

There is however, a problem, one that has been highlighted by Norman Geeson after he has extensively researched the company archives. He is meticulously trawling all the records of the development of our cars and has come up with a number of problems that existed on our engines but that were, in some instances, resolved on the later versions. This information is forming the basis of a series of articles, one of which has already appeared in the club bulletin and more of which will follow in the coming months. 

It appears that the engines in our cars run approximately 10-13 degrees C. hotter at the rear than at the front. If the temperature gauge shows 85-87degrees, as it can in hot weather, then the rear of the engine might be boiling and water loss will occur. Company records show that under extreme conditions, cylinder cracking can occur and, anyone who has rebuilt these engines will tell you that it is not unusual to find much greater wear on the rear cylinders than the front ones. 

Pressurising the system and improving cooling efficiency will reduce water loss but in hotter climates than the UK, (not difficult!) there is still the risk of premature wear and or lasting damage to the rear of the engine because it is running 10-13 degrees hotter than the reading on the gauge. Again Norman’s research has shown a solution, one that should be considered by anyone rebuilding an engine. 

There is a brass gallery that runs along the engine from the back of the water pump to the rear of the engine inside the water jacket. It has a series of holes that direct water to the exhaust valve guide bosses and then on the cylinders. Rolls-Royce continued to experiment with the size of these holes on the military B60 engine for many years after production of our cars had ceased with the result that, as the records show, a new tube could be made which helps to even up the temperature differential. Those interested should read pages 6, 7 and 8 of Norman’s piece in the Engine section where there are drawings of the later and more effective Gallery. It is entitled Cylinder Blocks and a few Deviations. Since in many cars, these tubes now require replacing, there is talk of making the later version. If this happens, then it will surely benefit everybody, but particularly those in hot climates. 

Norman has also suggested slightly reducing the size of the water pump pulley and has had some pulleys made and fitted to a number of cars including his own. This was an RR modification recommended “in all cases of overheating worldwide.” Therefore cars sent to Switzerland and Australia will probably already have them. 

For British owners who only experience very hot weather a couple of days of the year and can chose not to drive the car on these occasions, there is no serious problem as long as the cooling system is in perfect condition and provided they limit cruising speeds to a maximum of 65-70mph with the standard axle ratio. They can go 8% faster with the later R and S1 rear axle ratio and 17.45% faster with an overdrive or Continental one. However, there are other reasons for treating 65-70mph as a maximum cruising speed, not the least of which is the margin of safety in an old car. In cars that are still on the original cuff liners, it is probably prudent to reduce speeds by another 5mph to reduce the risk of piston failure. The real problems are faced by owners in hot climates and it is they who will benefit most from Norman’s work. 

Our cars have no cowling over the fan and it is some distance from the radiator, Kenlowe, makers of after market, electric fans will tell you that unless a fan is extremely close to the (1/8”) radiator, much of its energy wasted by drawing air from around the sides, rather than through it. Fitting an electric fan to the front of the radiators of our cars may well prove useful if the car is being used regularly in heavy traffic. 

To sum up: 

1.    Moderate speed to around 2,600 to 3000rpm max for prolonged cruising but a little slower if full-length liners are not fitted.

2.    Fit smaller fan pulley to reduce temperature rise in heavy traffic in hot weather.

3.    An electric, supplementary fan may also help.

4.    Change brass gallery in block to one of the later design if you are in a hot country and suffering water loss, i.e., Indicated temperatures of 85 degrees and over.

5.    Pressurising the system and fitting a modern more efficient radiator core is fine, provided the brass gallery is also changed to reduce the temperature differential between front and rear cylinders. 

Credit must go to Norman Geeson for taking an enormous amount of time trouble to meticulously document the history of the development of this exceptional engine and for highlighting a solution to what could otherwise be a serious problem. His articles will undoubtedly serve owners in good stead for the future. However having seen these and the solutions suggested to deal with overheating in the register news letter, it is clear that some may have problems Therefore  I discussed with Norman the idea of a condensed version which could be circulated immediately to those who need it before whole story appears in the bulletin. This is the result. 

Ashley James

January ‘03