Sample radiator assemblies (thanks Lyle!)

Clicky on the piccie for full size.

A couple of used radiator assemblies, from small engines such as motorcycles

First core, from a motorcycle engine I think. This one has low cross section, spaces between fins go straight through. This is best for our needs. I count 83 fins in 10cm, or about 1.2mm on centers.

Second core. This one has convolutions in the fins which increase the cross section, but that impedes airflow, which is what we don't want. I count 44 fins in 10cm, or 2.3mm on centers ... this is coarser than what we want, too.