Oil Cooler - 2" Diameter, 8" Length, 1" NPT Connection

This cooler features thirty-one 1/4" cooling tubes with displacement baffles. It also has 3/8" NPT oil connections with an 1/8" NPT drain. Operating pressure of up to 150 PSI. Designed for power steering or transmission applications.

Oil Cooler - 2" Diameter, 8" Length, 3/4" NPT Connection

This cooler features thirty-one 1/4" cooling tubes with displacement baffles.  It also has 3/8" NPT oil connections with an 1/8" NPT drain.  Operating pressure of up to 150 PSI.  Designed for power steering or transmission applications.

Oil Cooler - 2" Diameter, 9" Overall Length, 1-1/4" Hose Connection

This cooler features thirty-one 1/4" cooling tubes with displacement baffles. It also has 3/8" NPT oil connections with an 1/8" NPT drain. Operating pressure of up to 150 PSI. Designed for power steering or transmission applications.

Dual Tandem Oil Cooler - 2" Diameter, 18" Length, 3/4" NPT Oil Connections, 1-1/4" Push On Water Connections

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

Dual Tandem Oil Cooler - 2" Diameter, 18" Length, 3/8" NPT Oil Connections, 1" NPT Water Connections

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

Oil Cooler - 2" Diameter, 16" Overall Length, 1" NPT Connection

Featuring thirty-one 1/4" cooling tubes with displacement baffles! Large 3/4" NPT oil connections for increased flow with an 1/8" NPT drain. Rated operating pressure up to 150 PSI. Recommended for engines up to 425 horsepower.

Oil Cooler - 2" Diameter, 16" Overall Length, 1-1/4" Hose Connection

Featuring thirty-one 1/4" cooling tubes with displacement baffles! Large 3/4" NPT oil connections for increased flow with an 1/8" NPT drain. Rated operating pressure up to 150 PSI. Recommended for engines up to 425 horsepower.

Oil Cooler - 2" Diameter, 16 Overall Length, 3/4" NPT Connection

Featuring thirty-one 1/4" cooling tubes with displacement baffles! Large 3/4" NPT oil connections for increased flow with an 1/8" NPT drain. Rated operating pressure up to 150 PSI. Recommended for engines up to 425 horsepower.

Combination Engine Oil & Power Steering Or Transmission Cooler, 2" Diameter, 19" Overall Length, 3/8" NPT P/S and 3/4" NPT Oil Connections, 1-1/4" Water Connection

All the same features as our other coolers except it is designed as a MerCruiser replacement cooler for the 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 small than a 3/4" NPT oil connection on engine coolers.

Combination Engine Oil & Power Steering Or Transmission Cooler, 2" Diameter, 18" Length, 3/8" NPT P/S and 3/4" NPT Oil Connections, 1" NPT Water Connection

All the same features as our other coolers except it is designed as a MerCruiser replacement cooler for the 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 small than a 3/4" NPT oil connection on engine coolers.

Have you made some performance modifications and you're now making mega 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 down where they belong. This cooler features seventy-six 1/4" seamless cooling tubes and can handle form 450 to 750 horsepower applications with ease. With a 23" overall length, 3/4" NPT oil connections, 3/8" NPT P/S connections, and 1" water connections, this is the perfect solution.

Hi-Performance Engine Oil Cooler, 3" Diameter, 16" Overall Length, 3/4" NPT Oil Connections, 1" NPT Water Connection

Designed for engines making 450 horsepower and above.  These units have seventy-six 1/4" seamless tubes - over double that of a 2" cooler.  The cooler incorporates cast end caps, NO cheap press-formed caps are used.  Operating pressure up to 150 PSI.  This is the cooler all others try to imitate but can never duplicate.  Compare features and you will demand Hardin Marine oil coolers.

High performance 3" diameter oil coolers (above) are designed for engines making 450 HP and up. These units have seventy-six 1/4" seamless tubes and operate at 150 psi.

Hi-Performance Thermostatically Controlled Combination Cooler, 3" Diameter, 22" Overall Length, 1" NPT Water, 3/4" NPT Oil, & 3/8" NPT P/S Connections - For engines up to 700 HP, power steering and engine oil

Quite simply, the ultimate cooler on the market toady! It maintains an even, constant oil temperature thermostatically in one great unit. If you suffer from either high oil temperature or even moisture or condensation in your engine oil this the answer. The thermostat is designed to maintain an oil operating temperature between 190 degrees and 215 degrees. The thermostat causes the oil to bypass 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 of an oil temperature.

Hi-Performance Thermostatically Controlled Combination Cooler, 3" Diameter, 28" Overall Length, 1" NPT Water, 3/4" NPT Oil, & 3/8" NPT P/S Connections - For engines up to 1,000 HP, power steering and engine oil

Quite simply, the ultimate cooler on the market toady! It maintains an even, constant oil temperature thermostatically in one great unit. If you suffer from either high oil temperature or even moisture or condensation in your engine oil this the answer. The thermostat is designed to maintain an oil operating temperature between 190 degrees and 215 degrees. The thermostat causes the oil to bypass 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 of an oil temperature.

Hi-Performance Thermostatically Controlled Oil Cooler, 3" Diameter, 19" Length, 1" NPT Water Connections, 3/4" NPT Oil Connections - For engines up to 700 HP, engine oil only

Quite simply, the ultimate cooler on the market toady! It maintains an even, constant oil temperature thermostatically in one great unit. If you suffer from either high oil temperature or even moisture or condensation in your engine oil this the answer. The thermostat is designed to maintain an oil operating temperature between 190 degrees and 215 degrees. The thermostat causes the oil to bypass 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 of an oil temperature.

Hi-Performance Thermostatically Controlled Oil Cooler, 3" Diameter, 25" Length, 1" NPT Water Connections, 3/4" NPT Oil Connections - For engines up to 1,000 HP, engine oil only

Quite simply, the ultimate cooler on the market toady! It maintains an even, constant oil temperature thermostatically in one great unit. If you suffer from either high oil temperature or even moisture or condensation in your engine oil this the answer. The thermostat is designed to maintain an oil operating temperature between 190 degrees and 215 degrees. The thermostat causes the oil to bypass 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 of an oil temperature.

Big Block Chevy Gen 4 Bolt-On Cooler, 5" X 14-3/4" Length

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.

Big Block Chevy Gen 4 Bolt-On Cooler, 5" X 19-3/4" Length

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.