I went through the forum and there are different school of thoughts. Some said that there is no such thing as oil cooler being too big while others thought that oil pressure will be too low if the oil cooler is too big.

I bought an oil cooler that is 12" X 7" X 2" and running 1.8 NA. Will that be too big for me? I am using my car for street duty and monthly circuit racing.
Also, are eBay oil coolers a no no?

 

You want #10 lines, that size is probably fine, I wouldn't buy one on ebay unless it were a real brand. The line size will make pressure drop, not heat exchanger size.

 

...and since you don't have your location data posted, you might want to consider an oil thermostat...

 

Thanks Guys.
I am in Singapore, we have 31 degree temp all year round. I dont think I need a thermostat

 

You need a thermostat. Some of us need one on the track too.