Taking a quick look at one industrial radiator I had access to shows a cross flow. One reason is that it is easy to repair, just unbolt the header tanks, hammer in a brass plug in a leaking tube (both ends) and its back in service. This particular radiator is sized for 150% of engine rated BTU, allowing for some reduction in cooling efficiency with age.
BTW, modern radiators in industrial engins and gen-sets use a coolant conditioner which negates a substantial amount of corrosion and sediment buildup. The conditioner package comes in a small spin-on device which resembles a spin on oil filter. It does have recommended service intervals. Also, almost all over the road semi transports have this same setup. It is not uncommon for these trucks to go 1/2 million miles on one coolant change.
When disassembling these engines, we tell the technicians to look for pitting or corrosion points on the wet-sleeves.
Franz
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