1st Gen R53 Cooper S Most liked posts in thread: External Oil Cooler

You might want to add gauges and monitor temps before spending money on an oil cooler. I think for the street people have found that an external oil cooler is not necessary.
If you need the cooler for the track than you might also want to think about the RMW baffled oil pan.

 

A mini run on the street will likely need to have the oilcooler covered in cold weather to get oil temps HIGH enough to boil off moisture...
My thoughts...
In the days before syenthic oil, high temps destroyed oil....then destroyed the motor...
Now with syenthic oil, the oil does provide protection to much higher temps...and the factory heat exchanger can actually HELP warm up the oil in cold weather, reducing wear, etc..
Now on a track car, an oil cooler is a good thing IMO...reduces the load on the radiator, but for a combo track car/daily driver, I might suggest an oil change after a week end track event.....
Several folks have sold a machined plate to add a diy oil cooler in place of the factory heat exchanger over the years..... Since mini's run lower oil psi than some cars, I would be inclined to think making a homebrew cooler with some GOOD line, and "AN" fittings would work fine..but a pretested to fit kit would simply things for a few more $$.
And a thought...on heavy duty trucks, transmission Oil coolers are placed out of the airflow to prevent damage from rocks and debris...they radiate heat fine, even with very little airflow, so mounting location is less critical than one might think....added plus, an extra quart of oil added to the system (more or less)...
IMO, adding a baffled oil pan is a better first mod in this area...some folks do loose oil psi in long turns, and this WILL damage a motor...high oil temps will generally just shorten an oils life....but fresh oil after a weekend is cheap (mobil 1 euro, wallmart $40 ish)and easy, especially with a oil drain valve (fulmoto)...

 

No opinions on your oil cooler question. I'm happy with the Marshal gauges I installed a few years ago. Check my garage photos for the install configuration.

 

Jan @ RMW sells a good oil cooler. I don't have one but people that race MINI's like them.

 

No need for an oil cooler unless you are spending lots of time on the track.
Look at the ScanguageII, lots of available info on it. You can check my gallery for a shot of mine.