Visco fan RV8

jan_rrc39v8 · Post by **jan_rrc39v8** » Mon Mar 19, 2012 10:24 am

when running the car at 70mph for a while , then ending up in a traffic jam, the engine temp is creeping to the red zone. I managed to get some cooling by turning the heater on full power with the blower on.
I suspect a faulty viscofan.

I have a quick question:
will a visco fan of a P38 RR fit on the waterpump of my RR classic?

How can i test (without installing it) if the used part works?

DaveEFI · Post by **DaveEFI** » Mon Mar 19, 2012 10:56 am

You can do a rough check on the temperature controlled viscous coupling on the bench by playing a hot air gun on it. The input shaft should become much more difficult to turn - indeed pretty well solid.

ChrisJC · Post by **ChrisJC** » Mon Mar 19, 2012 1:29 pm

The P38 fan is different to the Classic fan. For a start, the water pumps are rotated in opposite directions!

Chris.

Ian Anderson · Post by **Ian Anderson** » Mon Mar 19, 2012 1:41 pm

ChrisJC wrote:The P38 fan is different to the Classic fan. For a start, the water pumps are rotated in opposite directions!

Chris.

That would account for overheating when in slow traffic with the natural flow of air and fan flow of air working against each other!

Ian

kiwicar · Post by **kiwicar** » Mon Mar 19, 2012 1:47 pm

Hi
have you back flushed the radiator? and probably be worth flushing the block while you are at it. I think it is far more likley to be the problem.
Best regrads
Mike

jan_rrc39v8 · Post by **jan_rrc39v8** » Wed Apr 11, 2012 2:30 pm

well, in the mean time i sourced a replacement visco fan.
I tested it by putting the nut in a vice and rotating the cold clutch , it was supposed to get progressively easier to turn (freewheeling modus)
It actually did to my surprise.
Then i took a paintstripper and held it to the back of the nut (still held in the vice), all the while turning the fan by hand. I could feel the clutch engaging. (blowing modus)

fitting it was easy, after i undid the shroud i could easily slide the old fan out between radiator and pump.

It seems to have done the trick, the engine can idle stationary for a day if need be and i can actually feel the fan actively blowing through the radiator.

I am ready for summer!

ChrisJC · Post by **ChrisJC** » Wed Apr 11, 2012 6:09 pm

Excellent news!

Chris.

jan_rrc39v8 · Post by **jan_rrc39v8** » Wed May 09, 2012 8:58 pm

lately ambient temps have been going up.
i had good hopes that my cooling problems were solved when i installed another viscofan.
I was wrong.... temp gauge nearly in the red. again!!
WTF!

This could only mean 1 thing: the radiator could not exchange/dissipate the heat into the air.
Either because there was no flow through the core (clogged by leaves? insects?) or the core was clogged internaly by chalk deposits...

i decided to try and look between the condensor (?? the airco cooler) and the radiator by pushing the rubber seal to the side and shining a beam of light down between them and....guess what i found....

a FRIGGIN' PIECE OF CARDBOARD!!! 20x50cm!!

it must have been left there by the previous owner. it was completely invisible with just the opened bonnet. No wonder the engine ran hot on warm days!

I pulled it out, went for a good hard trash. lots of hard acceleration and kickdown action. Then stop, wait and let the engine idle for a few minutes.
guage never went higher then 1/2. Problem solved!

ChrisJC · Post by **ChrisJC** » Thu May 10, 2012 7:03 am

Incredible!

Chris.