I visited with a local NSI subi builder here in Austin on Monday. This guy has the most hours on a NSI conversion. About 735 hours in the last two years. He has had a couple of failure due to assembly errors by NSI in their last days. His engine is a modified 4 cylinder turning about 200 HP. The package uses a single radiator with 735ci core and a small oil to water cooler. He has closed the space between the two air duct feeds to the radiator and attempted to radius the bends in the lower cowl ducts. I am amazed he is cooling as well as he is. He reports climb temps around 195-200 and cruise at 180 on hot days.
 
Bobby