High Flow Remote Oil Thermostat 165 F Part No. FSM-165 Made in USA Important: Read these instructions in their entirety prior to installation. Rev 160323
Application Notes The FSM series thermostat is designed for universal oil temperature control in engines, transmissions, differentials, and industrial cooling applications. Accelerates warm-up and prevents over-cooling. Under no circumstances can the thermostat fail in such a way that oil flow to the engine or heat source is blocked. Thermostat is re-buildable. Should the unit fail, it can be shipped back to Improved Racing for a rebuild with a new thermal element and seals. Not recommended for use with highly corrosive fluids. Technical Specifications Stabilization Temperature 167 F +/- 2 F (75 C +/- 1 C) Activation Temperature 160 F +/- 2 F (71 C +/- 1 C) Max Operating Temperature 302 F (150 C) Min Operating Temperature -22 F (-30 C) Max Recommended Pressure 200 psi (13.79 bar) Dimensions (W x H x D) 3.2 x 2.0 x 2.0 (8.13 x 5.08 x 5.08 cm) Weight (no brackets or fittings) 12.7 oz (360 g) Housing Material 6061-T6 billet machined aluminum Housing Finish MIL-A-8625 Type II anodizing, black Valve Material 6061-T6 billet machined aluminum Valve Finish Plain Spring Material 316 stainless steel Spring Finish Ultrasonic citric acid passivation Thermal Actuator Material Brass and zinc-plated steel Ports -10AN SAE J1926-1 / MS16142 O-ring boss Estimated Service Life > 5,000 heat cycles Operation The thermostat bypasses the oil cooler until the fluid reaches the activation temperature. At the activation temperature, the bypass valve begins to close, forcing oil through the cooler and allowing it to cool. If the cooler s cooling capacity is sufficient, the fluid will tend to stabilize at the rated stabilization temperature. 2
Oil from engine or transmission To engine or transmission Over 90% of oil flow is returned to the engine through the bypass valve to accelerate engine warm up and prevent over-cooling. To cooler Oil from cooler Less than 10% of oil flow circulates through cooler to prevent air pockets and shocking the system with cold oil. Oil from engine or transmission To engine or transmission Bypass valve closes, forcing 100% of oil flow through the oil cooler. If oil temps drop, the bypass valve opens to prevent over-cooling. To cooler Oil from cooler Figure 1 - Thermostat Operation Diagram Parts List FSM thermostat (1) Mounting brackets for up to 1/4 (6mm) screws (2) Bracket retaining screws, M4 x 0.7mm (4) AN adapter fittings (optional) (4) Flow Configurations 1. The recommended standard configuration (Figure 2) provides faster warm-up times. 2. The reverse configuration (Figure 3) will result in slower warm-up times. 3. The cross flow configuration (Figure 4) provides quick warm-up times like the standard configuration and may be a more convenient hose routing arrangement in certain applications. 3
Figure 2 - Standard Flow Figure 3 - Reverse Flow Installation Instructions Figure 4 - Cross Flow 1. Select a flow configuration and assemble oil lines to suit. The standard flow configuration is recommended. 2. Fill the oil cooler with oil prior to connecting the lines. Screw the AN adapter fittings to the thermostat housing, then connect the oil lines. 4
3. Tighten all fittings. Do not overtighten. Aluminum fittings are prone to damage and leaking if overtightened. 4. Check and top off the engine s oil level. 5. Remove the fuel pump fuse and crank the engine over for several seconds to build oil pressure and prime the lines with oil. 6. Replace the fuel pump fuse, then start the engine. 7. Check for leaks and adjust or tighten fittings if necessary. 8. Shut off the engine and top off the engine s oil level once again. 9. Congratulations! Installation is now complete. Thank you for purchasing an Improved Racing product! 5