Replacing Aluminium Fan with Electric?

[jedwards]

Gentlemen,
I have an early 250SL in very sunny Western Australia where temperatures during the coming  summer can easily reach 40C.  As I am tidying up my engine bay and have the radiator out , one option I have is to  install a 14” Kenlo electric fan (I have a spare) as an alternative to the original aluminium fan, driven via the water pump.   This is common “safety” measure  for classic cars in Australia.  There are a number of discussion on the forum about adding an additional electric fan to the front  of the radiator, but I can find little comment on the possibility of replacing the current mechanical fan with an electric unit with adjustable thermostat. There is the obvious negative of loss of originality, but the pros could potentially be worth considering,  even just as a safety measure for the summer months. 

Pros:
Deduced loading on water pump bearings extends water pump life
Greater air volume during idle
Faster warm up
1/2 horse power saved
Reduced engine noise
Reduced under-bonnet temperature
Greater control of temperature during hot weather

Cons:
Loss of originality (always reversible though)
Any other?

Jeff

[GGR]

I tried that. The car was overheating big time in city traffic in the heat. The mechanical fan is doing a much better job, even without a shroud. You just have to make sure the fan clutch works as it should. I have also replaced the propeller with a plastic 9 blades ones and fitted a thermostat that opens at a lower temperature. In my experience, an electric fan on a Pagoda is only justified as an additional device, as a pusher in the front.

[DavidBrough]

Jeff,

I've tried many different combinations of electric fans but the only one that worked for me was a twin Spal set up as noted here:-

http://www.sl113.org/forums/index.php?topic=16800.0

[Benz Dr.]

The 250SL has the largest rad of all thee models and should not overheat.

[WRe]

GGR,
what are your experiences with the 9 blades fan compared to the original 6 blades fan (fits the size, temperature, noise, etc.)?
....WRe

[GGR]

Contrarily to what I wrote in earlier posts, my fan was 8 blades, not 6. My major concern was noise. In terms of fitting, I had no problem, though I don't have a shroud. I read in other posts that someone had to trim the edge of the plastic fan for it to fit in the shroud. I'm very happy with the lower noise level. Much less that with the aluminum fan. In terms of cooling I guess there was an improvement, as one more blade compared to 8 is over an additional 12% air flux moving through the radiator (kind of?).

[mazmonza]

As an alternative to sort out my overheating problem when fast driving on hot days
I replaced my coolant with Evans classic 180 waterless coolant, seems to do the job.