Marine Oil Coolers

When only the best will do for the most severe conditions you will see why the armed forces Navy Seal Stealth boats chose the very best in engine oil cooling technology. These coolers were specially designed to maintain the maximum oil control on engines up to 800 horsepower with corrosion resistance that only stainless steel could offer. The multi-pass cupronickel core has been known to dissipate heat up to 20% faster than traditional copper style cooler cores.

This cooler is 3" in diameter and 19-1/2" long. It features 3/4" NPT oil ports and 1" NPT water ports.

This multi-plate design oil cooler assembly is used in virtually every severe duty type of oil cooling environment found today. Recognized by Mercury Racing and every high profile professional engine builders as the most effective method to control oil temperature. The 8, 13 and 15 plate oil cooler design offers maximum heat dissipation in the most compact size and use of available space. This is basically the same cooler package that's incorporated into a dual cooler style race bellhousing. Now you can have the same great cooling features in a remote mountable cooler.

The cast aluminum housing features a hard anodized finish for corrosion resistance. Each housing has 1" NPT water inlets and outlets plus a dual-bolt mounting flange and will accept a 8,13 or 15 plate cooler assembly when used with the appropriate cover assembly.

This cooler features thirty-one 1/4" cooling tubes with displacement baffles. It also features 3/8" NPT oil connections with a 1/8" NPT drain. It's operating pressure is up to 150 PSI. This is designed for power steering or transmission applications.

This cooler features thirty-one 1/4" cooling tubes with displacement baffles. It also features large 3/4" NPT oil connections for increased flow with an 1/8" NPT drain. It's operating pressure is up to 150 PSI. Recommended for engines up to 425 horsepower.

This cooler uses the same features as the coolers above except it is designed as a MerCruiser replacement cooler for most common V8 engines. The only noticeable difference is the use of 3/4" NPT oil connections providing a higher volume flow capacity.

Note: Never use smaller than 3/4" NPT oil connection on engine coolers.

This is one of the best designs anywhere. Two coolers and only one water hose connection. Each tube consists of thirty-one 1/4" seamless tubes with displacement baffles so you can be assured you're getting maximum cooling when you need it.

Hardin Marine's hi-performance 3" diameter oil coolers are designed for engines making 450 horsepower and above. Note that these units have seventy-six 1/4" seamless tubes - over double that of a 2" oil cooler. These coolers incorporate cast end caps, NO cheap press-formed caps are used. Their operating pressure is up to 150 PSI. This is the cooler all others try to imitate but never duplicate. Compare features and you will demand Hardin Marine oil coolers.

Have you made some performance modifications and now are making some real horsepower only to find out your stock Mercury cooler can't keep up. Well not only is this our most popular combination cooler, it is also the answer to getting those oil temperatures back where they belong.

This cooler features seventy-six 1/4" seamless cooling tubes and can handle from 450 to 750 horsepower applications with ease. With 25" overall length, 3/4" NPT oil connections, 3/8" NPT P/S connections, and 1" water connections, this is the perfect fit for any serious boater.

Quite simply, the ultimate oil cooler on the market today! It maintains oil temperature thermostatically and all in one unit. If you suffer from either high oil temperature or even moisture or condensation in your engine oil this is the answer. The oil thermostat is designed to maintain an oil operating temperature between 190 degrees and 215 degrees. The thermostat bypasses the cooler until operating temperature has been reached and then balances oil flow to maintain optimum oil temperature. This alone can save you from years of damage caused by operating your boat with too cold oil.

This Olsen hi-performance engine oil cooler has a unique feature - it bolts directly to the engine block and requires no additional oil plumbing. It merely sandwiches between the oil filter pad and oil filter. It is available in either 1-1/4" push-on fittings or AN style fittings to plumb the water inlet and exit. This cooler uses a large well designed 3" core and is available hard anodized or polished as an option. An offshore model is available to clear mid-engine motor mounts. This cooler completely disassembles for servicing.