Thread: Can this be done

Originally Posted by ryaninhilltop

On a tdi 300 could the viscous fan and pulley be removed, replaced by a thermo fan and a shorter serpentine belt be fitted. Any pro's & con's ?

So long as you don't drive any slower than 120 Kmh with a head wind it should be fine

Why would you want to do this anyway? As in another thread the viscous will move a heap more air than a thermo on its own due to HP requirement.

Originally Posted by Rangier Rover

So long as you don't drive any slower than 120 Kmh with a head wind it should be fine

Why would you want to do this anyway? As in another thread the viscous will move a heap more air than a thermo on its own due to HP requirement.

Just lazy I guess, don't want have to replace the bearing in the future.

A fan is just a means to an end - to force air through the intercooler ands radiator and around the motor to dissipate excess heat. It can consume a lot of power /useful energy/ fuel for no useful purpose when not needed.

Diesel motors are more efficient than petrol ones and for the same power output, less heat goes out through the radiator and exhaust. On my 300Tdi Defender, the viscous fan has been stored behind the seats in case needed since I changed the timing belt in May 2007 and the shroud, which appears to me an aerodynamic abomination regarding the intercooler has not been replaced. Neither has air conditioner condensor but have a more appropriate one, to go in front of the radiator and not the intercooler using flexible hoses so it can be swung outwards for cleaning.

Have done several small things to improve air flow, eg extra vent holes near rear in sides of guards, turned bottom piece of radiator intercooler cradle upside down so "legs" are downward and more importantly air gets through bottom of radiator instead of it blocking up with grass seeds etc. Also drilled holes in webbing bits in top of of aluminium casting on front of motor to help air flow. (Also extra ones in Magneti Marelli alternator, which is still not ventilated to minimise heat related problems as much as Bosch alternators.

When obstructions to air flow are minimised, not much wind is necessary. Fans are in themselves are obstructions and sometimes need to be used just because they are present.

Would not like to drive with no fan without simple and relatively fail safe anti overheating device, which unlike some other types, will generally stop the motor if unit itself fails rather than providing no protection, possibly without driver being aware of it. Wire from ignition switch to fuel solenoid on injector pump goes through temperature sensitive switch on cylinder head. Switch opens and stops motor if temperature gets to 105 degrees. Have had it stop motor once - after idling for half an hour while thinking all along that would be driving off within next minute.

With cooling components functioning properly, most of the time there is no need for a fan, with movement of the vehicle providing adequate airflow. However, undoubtedly a fan can compensate to some extent for faults such as radiator needing cleaning.

Mick

Originally Posted by mox

A fan is just a means to an end - to force air through the intercooler ands radiator and around the motor to dissipate excess heat. It can consume a lot of power /useful energy/ fuel for no useful purpose when not needed.

Diesel motors are more efficient than petrol ones and for the same power output, less heat goes out through the radiator and exhaust. On my 300Tdi Defender, the viscous fan has been stored behind the seats in case needed since I changed the timing belt in May 2007 and the shroud, which appears to me an aerodynamic abomination regarding the intercooler has not been replaced. Neither has air conditioner condensor but have a more appropriate one, to go in front of the radiator and not the intercooler using flexible hoses so it can be swung outwards for cleaning.

Have done several small things to improve air flow, eg extra vent holes near rear in sides of guards, turned bottom piece of radiator intercooler cradle upside down so "legs" are downward and more importantly air gets through bottom of radiator instead of it blocking up with grass seeds etc. Also drilled holes in webbing bits in top of of aluminium casting on front of motor to help air flow. (Also extra ones in Magneti Marelli alternator, which is still not ventilated to minimise heat related problems as much as Bosch alternators.

When obstructions to air flow are minimised, not much wind is necessary. Fans are in themselves are obstructions and sometimes need to be used just because they are present.

Would not like to drive with no fan without simple and relatively fail safe anti overheating device, which unlike some other types, will generally stop the motor if unit itself fails rather than providing no protection, possibly without driver being aware of it. Wire from ignition switch to fuel solenoid on injector pump goes through temperature sensitive switch on cylinder head. Switch opens and stops motor if temperature gets to 105 degrees. Have had it stop motor once - after idling for half an hour while thinking all along that would be driving off within next minute.

With cooling components functioning properly, most of the time there is no need for a fan, with movement of the vehicle providing adequate airflow. However, undoubtedly a fan can compensate to some extent for faults such as radiator needing cleaning.

Mick

With this philosphy how often do you crawl along in first low in a still valley with an external temperature of 55 degrees C.
Not often I suspect

I don't any over heating issues and not worried extra hp I just thought running without the fan and pulley (and running thermo fan) I don't have to worry so much about the bearing or casing.