Lots of posts on here recommending the Polo rad, but not a whole lot of information about which model to go for.. They range in core size from 380x320mm up to 630x405.

I am looking for the smallest possible radiator that'll keep a stock 3.5 motor cool. The engine will be in a lightweight trike and largely uncovered for lots of airflow. It won't be raced either, spending most of its life cruising at sub-3000 RPM.

Any suggestions?

here ya go:

polo rad

there's a chap on here with one of these keeping a supercharged toyota 4age with 260hp cool, and one kept my 200hp vauxhall xe cool with no problems at all, fan hardly ever came in even in traffic

Muchas gracias!

380x320 on my rover blocked 5l v8 no problems normally but we had to tape the external cooling air duct on to it on the rolling road.

Cheers!