13-04-2022, 08:09 AM
I have exactly the same issue as Keith - and funnily enough it was at Cobham Trial it showed itself. On my Special whoever designed it placed the rad so far forward of the fan as to render it all but useless.
It had not been a problem for years of normal road use, but when we started trialling some time ago we did find the engine was overheating and losing power. So I took the fan off and fitted a switchable electric fan - about 9" I think. We tried it out at Westerham last year but it failed failry quickly (buy cheap, buy twice) so I obtained a 10" replacement.
First time of using it in anger was Cobham last weekend and it performed really well - being switched on and off as required. However, I could see on the ammeter it was taking quite a bit of current (the car is 12 volts with an RB106 and the original three brush dynamo), maybe a negative 3-5 amp. By the end of the day the battery was very tired, though in fairness it probably was not fully charged to begin with.
I shall give it another go in due course.
It had not been a problem for years of normal road use, but when we started trialling some time ago we did find the engine was overheating and losing power. So I took the fan off and fitted a switchable electric fan - about 9" I think. We tried it out at Westerham last year but it failed failry quickly (buy cheap, buy twice) so I obtained a 10" replacement.
First time of using it in anger was Cobham last weekend and it performed really well - being switched on and off as required. However, I could see on the ammeter it was taking quite a bit of current (the car is 12 volts with an RB106 and the original three brush dynamo), maybe a negative 3-5 amp. By the end of the day the battery was very tired, though in fairness it probably was not fully charged to begin with.
I shall give it another go in due course.