Remote Engine & Transmission Oil Filter Mount with Thermostat, 185ºF

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SKU: ENV-171-T4
Regular price $299.00

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Improved Racing's remote oil filter mount features a built-in thermostat to save both space and cost. Intended for use with an oil cooler, the internal thermostat ensures engine oil reaches safe operating temperatures quickly and prevents over-cooling.

The ENV-171 is an evolution of Improved Racing's popular ENV-170 thermostatic remote filter mount and features the following improvements:

  • The internal passages were enlarged for improved flow characteristics.
  • Additional pocketing makes the ENV-171 12% lighter and the revised mounting points allowed the part to shrink in overall size.
  • The revised mounting bracket design is significantly stiffer and stronger.
  • The larger diameter oil filter flange can accept slightly larger oil filters than the ENV-170 (up to 3.55" diameter filter gaskets).
  • New design is patent pending

The thermostat valve is available in 185°F, 205°F and 215°F temperatures for use with engine oil. It's also available in 165° and 145°F ratings for use with transmission fluid. In most conditions, it will maintain oil returning to the engine or transmission at these minimum temperatures.

This remote filter head features female -10AN O-ring boss threads. Fittings are available to accommodate -6AN, -8AN, -10AN and -12AN lines, or 3/8" and 1/2" hose (-10AN lines are recommended for most applications).

This unit is available with an M22x1.50, 13/16"-16, or 3/4"-16 filter screw (sold separately). The filter screw is machined from hardened 410 stainless steel, which is stronger and more durable than common grades such as 304 and 316.

The extra sturdy mounting bracket is made from lightweight aluminum, and is Type II anodized for durability. Three different mounting orientations allow the inlet and outlet ports to be oriented universally for left-to-right or right-to-left flow.

Features and Benefits

  • Reduces excessive engine wear and horsepower losses while improving gas mileage by accelerating engine warm up and preventing oil temperatures from dropping below optimal levels
  • Oil flows through filter first (thermostat does not bypass the filter)
  • Allows a small percentage (roughly 5%) of fluid to continually circulate through the cooler to eliminate air pockets and prevent cold fluid trapped in the cooler from shocking the system
  • Rebuildable
  • Large M22x1.50, 13/16"-16, or 3/4"-16 filter thread bung is compatible with a wide range of filters
  • Compatible with filters with gaskets up to 3.55" in outer diameter
  • Filter screw is machined from hardened 410 stainless steel for excellent durability
  • 6061-T6 billet aluminum construction with black MIL-A-8625 Type II anodized finish
  • Extra sturdy, lightweight black anodized aluminum mounting bracket with 3 different mounting allows for right-to-left or left-to-right flow
  • Female -10AN O-ring boss ports
  • Patent-pending design
  • Made in USA
  • Lifetime Warranty

Flow Diagram and Operation


Three Mounting Bracket Orientations

6 Different Fitting Sizes Available

Optional 3/8" or 1/2'' hose barb, -6AN, -8AN, -10AN, or -12AN adapter fittings available


  • For use in remote oil filter applications where an engine oil cooler is also used. Not for use without an oil cooler.
  • Compatible with M22x1.50, 13/16"-16, and 3/4"-16 filter threads (filter thread adapter screw sold separately)
  • Compatible with filters with gaskets up to 3.55" in outer diameter


  • 1x Remote thermostat mount with integrated thermostat
  • 1x Aluminum mounting bracket and screws
  • 1x Aluminum backing plate and screws for strenghetning through-panel mounting applications

Recommended Oil Filter Part Numbers

13/16"-16 filter thread:

  • Wix 51794R
  • Wix 51060R
  • Wix 51061R
  • Wix 51069R
  • Wix 51042XP
  • Fram HP4

M22x1.50 filter thread:

  • Wix WL7421
  • Wix WL10058
  • Fram PH3616
  • AC-Delco PF2156
  • Purolator L30248
  • Royal Purple 20-820
  • K&N HP-2010
  • Fram PH2
  • Purolator L24651
  • microGreen MG421-8
  • Fram HP19
  • AC-Delco PF26
  • Wix 51372
  • Wix 57899
  • Mobil 1 M1-210
  • Mobil 1 M1-212
  • Royal Purple 20-500
  • Wix WL7421
  • Bosch 3502
  • Purolator L22500
  • Fram PH10575
  • Mobil 1 M1-113
  • Royal Purple 10-48
  • Wix 57502
  • Fram HP18

* For a more comprehensive list of compatible filters, please see the documentation section.


Part #
Improved Racing
Part Weight
15.6 ounces (443 grams)
Primary Material
6061-T6 aluminum
Type II Anodized
Minimum Operating Temperature
-40°F (-40°C)
Maximum Operating Temperature
302°F (150°C)
Inlet Port Size
-10AN O-Ring Boss Female
Outlet Port Size
-10AN O-Ring Boss Female
Maximum Operating Pressure
300 psi (20.68 bar)
Max Recommended Flow Rate
Up to 20 GPM (76 LPM)
Fluid Compatibility
Engine oil
Gear oil
Transmission fluid
Oil Filter Flange Inner Diameter
1.90" (48.3mm)
Oil Filter Flange Outer Diameter
3.55" (90.2mm)


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