Providing enough cooling for an engine to meet its tier requirements often results in keel coolers becoming quite large, big enough “to start running out of hull space,” says Duramax’s Lewis Foster. Both Duramax Marine and R.W. Fernstrum have sought to overcome this lack of space with stacked coolers that basically double the amount of cooling without increasing a keel cooler’s footprint.

Duramax’s DuraCooler SuprStak features convergent headers and turbulizer spacers, as well as flow diverter scoops to disrupt and agitate the flow of seawater around the keel cooler to increase its efficiency.

Fernstrum also offers a stacked grid cooler to reduce the keel cooler’s footprint and the number of units required. Fernstrum is also the only company to offer an aluminum keel cooler designed for unpainted aluminum hulls.

In cases where you might want to match up a new keel cooler with an existing cooler but piping inside a boat is a bit crowded or there’s a watertight compartment, an End Model keel cooler from Walter Machine should work. The End Model keel cooler only has one through-hull fitting, which contains both the inlet and outlet, as opposed to one at each end. Thus there are more options as to where to place the End Model cooler.

Check out our full feature on keel and grid coolers in the June issue of National Fisherman.

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Michael Crowley is the former Boats & Gear editor for National Fisherman.

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