Post Number: 3
|Posted on Saturday, 07 July, 2012 - 03:11 pm: |
I put a post in general about noise from the front of the engine bay and a loss of power. I got a few responses (thanks) but now I am reading a bit more on the forum I see that if the viscous coupling is engaged all the time there is a noise and a loss of power. Should the fan not move on start up and only start to move when the engine heats up? My fan spins all the time.
I can spin the fan when the engine is switched off - does this mean it should be OK and the noise is something else?
Post Number: 351
|Posted on Sunday, 08 July, 2012 - 07:41 pm: |
The fan should rotate all the time the engine is running, but unless it's up to temperature there won't be any apreciable power behind it. In practice a rolled up newspaper should be able to stop it dead in its tracks although extreme care should be taken if you want to test this out!
gordon le feuvre
Yet to post message
Post Number: 1
|Posted on Sunday, 08 July, 2012 - 08:13 pm: |
THE FAN WILL ROTATE WITH ENGINE OFF. THE WAY WE USED TO TEST WAS TO START ENGINE FROM COLD ON FAST SPEED . DO NOT KNOCK CHOKE SPEED OFF AS ENGINE WARMS UP. THE FAN WILL ROAR FOR A SHORT TIME ON INITIAL START, THEN GO INTO FREE WHEEL MODE (NO FAN ROAR) AS ENGINE GETS HOT(NORMAL TEMPA ND ABOVE) FAN CAN BE HEARD TO START DRIVING AS WAX GETS HOT IN VISCIOUS UNIT THERE IS NOTICABLE INCREASE IN FAN ROAR. WE CHOKE IS KICKED OFF AND ENGINE STOPPED, FAN CAN STILL BE ROTATED FREELY. WARNING: WHEN DOING ANY WORK LIKE THIS GOOD PRACTICE IS TO MAKE SURE CAR IN PARK WITH IGNITION ON ONLY, THEN REMOVE ISLOATOR FROM FUSEBOARD. THIS ISLOATES GEAR SELECTOR, SO THAT A GEAR CANNOT BE INADVERTELLY SELECTED BY KNOCKING SELECTOR LEVER WITH CAT ON FAST IDLE. OUT OF INTEREST, THE EARLY CARS HAD FIXED FANS, JUST BOLTED TO WATER PUMP SO I CANNOT SEE THAT EVEN IF FAN SEIZED THIS WOULD ROB APPRECABLE AMOUNT POWER, JUS MAKE FAN ROAR VERY APPARENT
GORODN LE FEUVRE
Posted From: 220.127.116.11
|Posted on Sunday, 08 July, 2012 - 06:03 am: |
THE VISCOUS FAN WILL SPIN FROM COLD WITH ENGINE OFF.START ENGINE FROM COLD, FAN SHOULD JUST ROTATE SLOWLY. AS ENGINE GETS HOT(DO NOT KICK CHOKE SPEED OFF) VISCOUS WILL BE SEEN TO START DRIVING FASTER, THIS WILL ALSO BE HEARD AS INCREASING FAN "ROAR" THIS MEANS VISCOUS OK. THE FAN SEIZING OR DRIVING ALL TIME WILL NOT IN IT'SELF SHOW AS POWER LOSS, EARLY UK ? CARS ALL HAD FIXED FANS AND THEY WORKED, UP TO ABOUT 4000 CHASSIS NO.
PLEASE NOTE: WHEN CARRYING OUT TASKS LIKE THIS IN SHOP OR ANYWHERE, GEAR SHOULD BE IN PARK, AND GEAR SELECTOR ISOLATOR REMOVED FROM FUSE BOX BEFORE RUNNING UP ENGINE, THIS MEANS THAT IF YOU ACCIDENTALY TOUCH/KNOCK GEAR SELECTOR, CAR WILL NOT TAKE OFF!
(Message approved by david_gore)