Here's a post from the Yahoo! site on the subject of cooling by Nathan Keith:
"Before making any modifications check that the temperature gauge is correct with an accurate temperature gun.
Going back to my racing days, we would always add an oil cooler (especially important in the days before synthetic oil), electric fans (they don't create engine drag when not in use), and three row aluminum cross flow radiators (an extra row over stock and aluminum dissipates heat much better than steel or copper), and larger water pump pulleys (water flowing too fast does not cool as well in the radiator, and in racing you are often at high rpm). Anyone who had done any severe towing with the air cooled VW van (mico-bus) knows the value of an oil cooler with a fan.
I found the oil filer mount for the oil cooler on ebay for $5 (how many times do you ever have to change this part?), mounted a trailer towing style automatic transmission oil cooler if front of the radiator and
have had no temperature problems since. You can also buy a thermal switch, i.e. the oil only circulates through the cooler if it gets hot enough.
I did this because my research showed that oil will transmit more heat out of the motor more quickly than water. The big racers use a big oil cooler and a dry sump (requires a dual chamber oil pump) to cool the
oil even further.
Now every coin has two sides. An engine that is running too cool will not be efficient and this is where accurate thermostats are critical. I use a temperature gun to check the temperature that the thermostat
opens. The temperature gun can also be used to check the head and determine if a cylinder is running hot or cold (usually due to a bad cam or timing).
The temperature gun I use:
http://www.professionalequipment.com/xq/ASP/ProductID.287/id.22/subID.177/qx/default.htmFor oil coolers check out
http://www.summitracing.com/ and search on "engine oil cooler"
A good radiator shop can fit an aluminum cross flow radiator into the SL."
Cees Klumper in Amsterdam
'69 white 280 SL automatic