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Oil Systems - Thermostatic Oil Control

Polished Horizontally Mounted ​ Thermostatically Controlled Engine ​ Oil Filter Mount
Your Price:
$595.99

Polished Horizontally Mounted ​ Thermostatically Controlled Engine ​ Oil Filter Mount

625-7701

Polished Horizontally Mounted ​ Thermostatically Controlled Engine ​ Oil Filter Mount

Maintaining proper engine oil temperature has become critical to the success or failure of today’s performance marine engines. Prolonged use of marine engines in conditions where oil cannot reach its optimum working temperatures will result in sludge formation and crankcase dilution which leads to excessive wear especially in the cylinder bores and bearing surfaces. A thermostat assembly combats this by permitting 90% of the engines oil to bypass the cooler during warm up. The balance of the oil flow is allowed to flow through the cooler maintaining constant pressure and preventing air pockets while eliminating cold oil shock. This reduces scuffing and premature wear and inhibits engine blow-by. As engine oil temperature reaches its optimum operating temperature moisture and impurities that often cause a milky condition are eliminated.

With this unit all oil temperature is now controlled through a integral 212 degree oil thermostat. The large -12 O-Ring style port fitting oil inlets/outlets assure the maximum amount of oil can be flowed through the unit. Accepts either: FRAM *HP4 / HP6 style Oil Filter *


Polished Remote Bulkhead Mount ​Thermostatically Controlled Engine​ Oil Filter Mount
Your Price:
$499.95

Polished Remote Bulkhead Mount ​Thermostatically Controlled Engine​ Oil Filter Mount

625-7713

Polished Remote Bulkhead Mount ​Thermostatically Controlled Engine​ Oil Filter Mount

  • ​Remote Mount ​
  • Thermostatically Controlled Engine
  • ​Oil Filter Mount

Maintaining proper engine oil temperature has become critical to the success or failure of today’s performance marine engines. Prolonged use of marine engines in conditions where oil cannot reach its optimum working temperatures will result in sludge formation and crankcase dilution which leads to excessive wear especially in the cylinder bores and bearing surfaces. A thermostat assembly combats this by permitting 90% of the engines oil to bypass the cooler during warm up. The balance of the oil flow is allowed to flow through the cooler maintaining constant pressure and preventing air pockets while eliminating cold oil shock. This reduces scuffing and premature wear and inhibits engine blow-by. As engine oil temperature reaches its optimum operating temperature moisture and impurities that often cause a milky condition are eliminated.

With this unit all oil temperature is now controlled through a integral 212 degree oil thermostat. The large -12 O-Ring style port fitting oil inlets/outlets assure the maximum amount of oil can be flowed through the unit. Accepts either FRAM *HP4 / HP6 style Oil Filter *


Big Block Chevy Gen 5 & 6 Thermostatically Controlled Engine Block Adapter
Your Price:
$279.99

Big Block Chevy Gen 5 & 6 Thermostatically Controlled Engine Block Adapter

625-7704

Big Block Chevy Gen 5 & 6 Thermostatically Controlled Engine Block Adapter

Thermostatically Controlled Engine Block Adapter Gen 5/6 BBC

Maintaining proper engine oil temperature has become critical to the success or failure of today’s performance marine engines. Prolonged use of marine engines in conditions where oil cannot reach its optimum working temperatures will result in sludge formation and crankcase dilution which leads to excessive wear especially in the cylinder bores and bearing surfaces. A thermostat assembly combats this by permitting 90% of the engines oil to bypass the cooler during warm up. The balance of the oil flow is allowed to fl ow through the cooler maintaining constant pressure and preventing air pockets while eliminating cold oil shock. This reduces scuffing and premature wear and inhibits engine blow-by. As engine oil temperature reaches its optimum operating temperature moisture and impurities that often cause a milky condition are eliminated.

Until now oil temp was controlled either by some guess of components or by the professional engine builders through the use of some sort of external engine oil thermostat. While these external oil filter/ thermostats were very effective they were also very large and very bulk . Making them hard to mount and creating a maze of plumbing. The problem was the only available parts up until now couldn’t move the necessary oil fl ow to be mounted anywhere. else. But thanks to Hardin marine and their engineering staff they took to solving this decade long nuisance. Hardin Marine has developed this new thermostatically controlled engine block mounted product. With this unit all oil temperature is now controlled through a integral 212 degree oil thermostat. The large 3/4NPT oil inlets/outlets assure the maximum amount of oil can be fl owed through the unit. So no more maze of external plumbing, no more big bulky external mounted components just the standard (2) lines to the filter and the standard (2) lines to your cooler. Sometimes evolution comes in the form of the simplest of things but this is one that has been deeply sought after. Overall Height: 4-3/4"



Black Horizontally Mounted ​ Thermostatically Controlled Engine ​ Oil Filter Mount
Your Price:
$599.99

Black Horizontally Mounted ​ Thermostatically Controlled Engine ​ Oil Filter Mount

625-7702

Black Horizontally Mounted ​ Thermostatically Controlled Engine ​ Oil Filter Mount

Maintaining proper engine oil temperature has become critical to the success or failure of today’s performance marine engines. Prolonged use of marine engines in conditions where oil cannot reach its optimum working temperatures will result in sludge formation and crankcase dilution which leads to excessive wear especially in the cylinder bores and bearing surfaces. A thermostat assembly combats this by permitting 90% of the engines oil to bypass the cooler during warm up. The balance of the oil flow is allowed to flow through the cooler maintaining constant pressure and preventing air pockets while eliminating cold oil shock. This reduces scuffing and premature wear and inhibits engine blow-by. As engine oil temperature reaches its optimum operating temperature moisture and impurities that often cause a milky condition are eliminated.


Black Remote Bulkhead Mount ​Thermostatically Controlled Engine​ Oil Filter Mount
Your Price:
$499.95

Black Remote Bulkhead Mount ​Thermostatically Controlled Engine​ Oil Filter Mount

625-7714

Black Remote Bulkhead Mount ​Thermostatically Controlled Engine​ Oil Filter Mount

  • ​Remote Mount ​
  • Thermostatically Controlled Engine
  • ​Oil Filter Mount

Maintaining proper engine oil temperature has become critical to the success or failure of today’s performance marine engines. Prolonged use of marine engines in conditions where oil cannot reach its optimum working temperatures will result in sludge formation and crankcase dilution which leads to excessive wear especially in the cylinder bores and bearing surfaces. A thermostat assembly combats this by permitting 90% of the engines oil to bypass the cooler during warm up. The balance of the oil flow is allowed to flow through the cooler maintaining constant pressure and preventing air pockets while eliminating cold oil shock. This reduces scuffing and premature wear and inhibits engine blow-by. As engine oil temperature reaches its optimum operating temperature moisture and impurities that often cause a milky condition are eliminated.

With this unit all oil temperature is now controlled through a integral 212 degree oil thermostat. The large -12 O-Ring style port fitting oil inlets/outlets assure the maximum amount of oil can be flowed through the unit. Accepts either FRAM *HP4 / HP6 style Oil Filter *


Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,199.99

Plate Style Engine Oil Control Kit Up To 1300HP, Gen 4 BBC, Thermostatic

620-904

  • For Gen 4 BBC Applications.
  • 13 Plate Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,199.99

Plate Style Engine Oil Control Kit Up To 1300HP, Gen 5/6 BBC, Thermostatic

620-885

  • For Gen 5/6 BBC Applications.
  • 13 Plate Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,179.99

Plate Style Engine Oil Control Kit Up To 900HP, Gen 4 BBC, Thermostatic

620-884

  • For Gen 4 BBC Applications.
  • 8 Plate Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,179.99

Plate Style Engine Oil Control Kit Up To 900HP, Gen 5/6 BBC, Thermostatic

620-880

  • For Gen 5/6 BBC Applications.
  • 8 Plate Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Replacement Thermostat for Thermostatic Oil Adapter
Your Price:
$65.99

Replacement Thermostat for Thermostatic Oil Adapter

625-7762

Replacement thermostat for 625-7704 adapter and all kits it is included in.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,079.99

Tube Style Engine & Power Steering Oil Control Kit Up To 700HP, Gen 4 BBC, Thermostatic

620-854

  • For Gen 4 BBC Applications.
  • 3" x 25" Oil & Power Steering tube Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,079.99

Tube Style Engine & Power Steering Oil Control Kit Up To 700HP, Gen 5/6 BBC, Thermostatic

620-850

  • For Gen 5/6 BBC Applications.
  • 3" x 25" Oil & Power Steering tube Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,029.99

Tube Style Engine Oil Control Kit Up To 1000HP, Gen 4 BBC, Thermostatic

620-824

  • For Gen 4 BBC Applications.
  • 3" x 24" Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$1,029.99

Tube Style Engine Oil Control Kit Up To 1000HP, Gen 5/6 BBC, Thermostatic

620-825

  • For Gen 5/6 BBC Applications.
  • 3" x 24" Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$995.99

Tube Style Engine Oil Control Kit Up To 700HP, Gen 4 BBC, Thermostatic

620-804

  • For Gen 4 BBC Applications.
  • 3" x 16" Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Tube Style Engine Oil Control Kit Up To 700HP
Your Price:
$995.99

Tube Style Engine Oil Control Kit Up To 700HP, Gen 5/6 BBC, Thermostatic

620-800

  • For Gen 5/6 BBC Applications.
  • 3" x 16" Oil Cooler with Polished Brackets.
  • 6' of Push-Loc Hose included.
  • Includes 625-7704 Thermostatically Controlled Engine Block Adapter.
  • Includes 8 Straight and 8 90 Degree Fittings for installation.

Vertical Mount Thermostat Filter Head - Black
Your Price:
$599.95

Vertical Mount Thermostat Filter Head - Black

625-7712

Vertical Mount Thermostat Filter Head - Black

Maintaining proper engine oil temperature has become critical to the success or failure of today’s performance marine engines. Prolonged use of marine engines in conditions where oil cannot reach its optimum working temperatures will result in sludge formation and crankcase dilution which leads to excessive wear especially in the cylinder bores and bearing surfaces. A thermostat assembly combats this by permitting 90% of the engines oil to bypass the cooler during warm up. The balance of the oil flow is allowed to flow through the cooler maintaining constant pressure and preventing air pockets while eliminating cold oil shock. This reduces scuffing and premature wear and inhibits engine blow-by. As engine oil temperature reaches its optimum operating temperature moisture and impurities that often cause a milky condition are eliminated.


Vertical Mount Thermostat Filter Head - Polished
Your Price:
$599.95

Vertical Mount Thermostat Filter Head - Polished

625-7711

Vertical Mount Thermostat Filter Head - Polished

Maintaining proper engine oil temperature has become critical to the success or failure of today’s performance marine engines. Prolonged use of marine engines in conditions where oil cannot reach its optimum working temperatures will result in sludge formation and crankcase dilution which leads to excessive wear especially in the cylinder bores and bearing surfaces. A thermostat assembly combats this by permitting 90% of the engines oil to bypass the cooler during warm up. The balance of the oil flow is allowed to flow through the cooler maintaining constant pressure and preventing air pockets while eliminating cold oil shock. This reduces scuffing and premature wear and inhibits engine blow-by. As engine oil temperature reaches its optimum operating temperature moisture and impurities that often cause a milky condition are eliminated.


Fitting Coupler - 1/2" NPT to -12 AN
Your Price:
$18.99

Fitting Coupler - 1/2" NPT to -12 AN

625-7241

Fitting Coupler - 1/2" NPT to -12 AN (O-ring for use on Bellhousing Cooler)


Fitting Coupler - 3/4" NPT to -12 AN
Your Price:
$18.99

Fitting Coupler - 3/4" NPT to -12 AN

625-7242

Fitting Coupler - 3/4" NPT to -12 (O-ring for Remote Filter Use)