Electric cooling fan for 280SL

[PIP1947]

Can anyone advise on whether or not the standard alternator on my 1968 280SL will handle the load of a large (say 12") electric sucker fan, to be installed in place of the existing belt driven item? My car is a daily driver and, in Sydney's increasingly dense traffic on hot days (30 - 35 deg. Celsius (up to 100 Farenheit) the temperature climbs inexorably from the normal 180F to well over 200, especially with the aircon operating. I would consider a bigger alternator, but space is tight down there! Thanks.

Pip1947
1965 230 SL mid red/black (sold)
1968 280 SL Tunis Beige Metallic/dark brown soft top & interior

[cfm65@me.com]

Hi Pip,
I am sure the electrical system will cope and that a larger alternator would not be nessecary. However, I would not remove the existing fan setup. I would spend some time to service the entire cooling system before doing any mods. I realise there is not much space but I would then consider an extra fan in front of the radiators.
Regards
Chris
Cape Town

[PIP1947]

Thanks Chris. I would prefer to retain the existing alternator, so that's good news. I'm pretty sure my cooling system is in good shape, having been fully overhauled in the late 90's and maintained carefully ever since. The gauge only goes above the horizontal when stationary for long periods on very hot days. Unfortunately, this is unavoidable in central Sydney, where I live. I already have a small 'pusher' fan in front of the radiator, but it is not big enough to cope. Cheers
Pip

[guyke]

why dont jou let build a custom aluminieum radiator , little larger , and 2 electric fans on them ,
http://www.ebay.co.uk/itm/NISSAN-200SX-S14-S14A-S15-SR20DET-1993-99-Race-Radiator-Custom-Fan-Shroud-/122175131455?hash=item1c72348f3f:g:CyYAAOSwYIxX-0Xi
someting like this , but it is not for the w113 , its to give jou an example

[hauser]

Andy has added an electric fan to his 280sl.

[doitwright]

There is an old thread from a user that experimented with radiator record, electric fan, factory fan and an electric water pump and eventually found adding the electric water pump did the best job at keeping the temp down. Keep us posted on what you find works for you.

[Travis71280]

If the electric water pump helped cooling more (I remember that thread you are talking about), I would imagine overdriving the water pump would help cooling as well (I.e. running a smaller water pump pulley to make the pump spin faster for a given rpm, thus increasing flow rate). Has anyone ever tried this?

[guyke]

If the electric water pump helped cooling more (I remember that thread you are talking about), I would imagine overdriving the water pump would help cooling as well (I.e. running a smaller water pump pulley to make the pump spin faster for a given rpm, thus increasing flow rate). Has anyone ever tried this?

i tried that on my 2.2 mercedes unimog engine , and it works incredible good , when jou look closer i had my radiator mounted on the back from the truck , because when we are doing some off road whit it and and ride in the mud , the radiator always keep fulling whit mud so i had no ar few cooling , so i placed it in the back , and putted a small pulley on the engine to increase the flow , it was almoast the same engine as on the pagoda

[Tyler S]

Pip, Do you have a fan shroud installed? That makes a big difference.
Also adjusting the idle solenoid to kick the rpms up twards 1000 rpm when the air con is running will have the water pump and fan spinning faster to reduce temp.

[PIP1947]

Thanks Tyler. I have kicked the idle up a bit, but I'm most intrigued by what you say about the fan shroud. I suspected it might make a difference, but have been unable to obtain one in Australia. In fact, I don't think they were ever fitted to Australian or UK delivered cars. I did once see a second hand shroud on Bud's website, but delivery costs made it uneconomic to purchase the item. Now that you confirm the usefulness of the shroud, I will make further efforts to obtain one. Cheers.
Pip

[hauser]

Bud's has reproduction shrouds for sale.

[peterm]

Horrible problem with cooling when I first purchased my car.  Tried water wetter, recoring radiator, new water pump etc etc nothing really helped couldnt use aircon in summer unless moving.  Then the system magically was fixed when my mechanic slammed into another car when test driving mine 27,000$ later (his insurance not mine) new radiator fan water pump etc etc its now fine.

[PIP1947]

Thanks Peterm. Your experience suggests to me that the problem lies with the radiator. After the accident, your car probably acquired a more efficient radiator, thus curing the problem. My problem is not severe, only becoming apparent in heavy traffic and in temperatures above about 35 Celsius (95 Farenheit). At normal speeds, the gauge sits happily at 180, regardless of the temperature and whether or not the aircon is running. My radiator has been re cored, but I'm beginning to think age has taken its toll and that it may be time to consider a new, high efficiency aluminium radiator.
PIP1947

[GGR]

I tried replacing the original fan with an electric one (the best and biggest diameter I could find) and the result was worse.

I went back to the mechanical fan but fitted a fan shroud and a 9 blades plastic fan propeller. It is now OK.

Make sure your fan clutch is working properly. You can do the rolled paper test. Roll a news paper and try to stop the propeller when the engine is idling and hot. If you can stop it then the fan clutch is bad. A bad fan clutch will have your engine overheat in traffic.

[PIP1947]

Thanks GGR for what is yet more helpful information. Your experience confirms the view that an electric fan is probably not the way to go. I wasn't aware of the availability of 9 blade plastic fans to fit the 280SL, but I will see if I can find one - what an excellent idea, as I'm sure it would pump a lot more air.

If you can direct me to a source for such a fan blade, that would be much appreciated.

So far, I have resisted buying a shroud, as it will be costly. Shrouds were an option in the US only, so there are none for sale in Australia. Buds charges US $325 for a reproduction, which translates to about AU$500 for me. Freight, fitting and tax could take that to nearly $1000, so I would want to be sure of gaining a significant benefit!

I will also apply the "rolled paper test" to my fan, to test clutch operation. I had assumed that the fan clutch was ok just by virtue of the fan turning at idle, so I am very grateful for your tip.

I will report back on all my findings.

Regards
PIP1947

[GGR]

Google the 1102000323 part number. I think this is the one I fitted. You can also look into adapting a W108 fan shroud. I adapted one from a W108 4.5L. It will require some adaptation but you may find a used one for cheap.

[WRe]

Hi,
both parts GGR mentioned are still available at MB but also as OEM parts and used.
- 9 blade fan: A1102000323 (MB: 58€)
- fan shroud: A1085050255 (67/53/5 cm), A1095050455, replaced by A1095050855 (66/55/4 cm) (MB: 50€)
There had been other threads about this and I would be interessted in their results:
- https://www.sl113.org/forums/index.php?topic=18979.msg144667#msg144667
- https://www.sl113.org/forums/index.php?topic=11810.msg80388#msg80388
...WRe

[Travis71280]

You could also try and fab up (or find someone who is good at metal fabrication) a shroud out of sheet metal.