Improved Racing's Flow Series Compact (FSC) oil thermostat is an ultra-compact unit designed for use in cooling systems for transmissions, differentials, transaxles and small engines where flow rates do not exceed 5 GPM. This thermostat is perfect for engine oil cooling in motorcycles, ATVs, go karts, and other small engines.
The patented internal design (US patent 9,772,632) minimizes the pressure drop by strategically locating the bypass valve mechanism completely out of the primary fluid flow. This design is ideal for demanding applications that require low flow restriction in a compact and lightweight design.
Why Use a Thermostat?
Without a thermostat, engine oil, transmission fluid, gear bluid, and power steering fluid coolers may over-cool the fluid, delaying engine warm-up and resulting in horsepower loss, excessive engine wear, hard shifting, and reduced gas mileage. Oil thermostats perform the critical function of bypassing the cooler until the oil has reached its minimum operating temperature. A more capable cooler will often require an oil thermostat in order to maintain proper operating temperatures under low load conditions, cold weather, etc.
The thermostat maintains the oil exiting the engine at the rated minimum temperature in most conditions. It features female -6AN O-ring boss threads and is available with optional hose barb and male AN adapter fittings. The included brackets allow for multiple mounting options.
Operation
Features and Benefits
- Reduces excessive engine wear and horsepower losses while improving gas mileage by preventing oil temperatures from dropping below optimal levels
- Patented, high flow, low pressure drop design locates the valve assembly completely out of the primary fluid flow
- Maintains a minimum fluid temperature according to the typical stabilization temp in the table below, +/- 2°F (+/- 1°C)
- Allows a small percentage (less than 10%) 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
- 6061-T6 billet aluminum construction with black MIL-A-8625 Type II anodized finish
- Lightweight at just 7.5 ounces (212g) without brackets or fittings
Temperature Rating Specifications
| Part Number | Typ. Stabilization Temp | Activation Temp | Full Flow Temp |
|---|---|---|---|
| FSC-135 | 135ºF (57ºC) | 131ºF (55ºC) | 153ºF (67ºC) |
| FSC-145 | 145ºF (63ºC) | 140ºF (60ºC) | 163ºF (73ºC) |
| FSC-165 | 165ºF (74ºC) | 160ºF (71ºC) | 181ºF (83ºC) |
| FSC-185 | 185ºF (85ºC) | 180ºF (82ºC) | 203ºF (95ºC) |
| FSC-205 | 205ºF (96ºC) | 200ºF (93ºC) | 221ºF (105ºC) |
| FSC-215 | 215ºF (102ºC) | 212ºF (100ºC) | 233ºF (112ºC) |
Valve assembly is completely housed between the two ports.
No valves, springs, or thermal motor interrupting the primary oil flow!
Ultra-compact dimensions (shown in inches)
Brackets allow for multiple mounting configurations
Available with optional hose barb and male AN adapter fittings
Applications
- Fluid cooling systems flowing up to a maximum of 5 GPM (18.93 LPM).
- Fluid cooling systems for automotive and small vehicle transmissions, transaxles, transfer cases and differentials.
- Oil cooling systems for small engines such as motorcycles, ATVs, go karts, snowmobiles, and small marine engines.
- Not for use with corrosive fluids. If used with water, a distilled water solution with a lubricant such as ethylene glycol must be used.
Includes
- 1x Compact remote thermostat block
- 2x Zinc-plated steel mounting brackets and screws
Optional Parts Sold Separately
Line Adapter Fittings (Optional)
Use these fittings to adapt the ports to the line sizes listed below. These fittings are required except when using hose ends with male O-ring boss connections.
Note: Our fittings are required to guarantee compatitility with our thermostats, as some aftermarket fittings may cause interference and improper function.
| Line Size | Part Number | Qty Required |
| 5/16" Barb | OB-06-05 | 4 |
| 3/8" Barb | OB-06-06 | 4 |
| 1/2" Barb | OB-06-08 | 4 |
| -4AN | OM-06-04 | 4 |
| -6AN | OM-06-06 | 4 |
| -8AN | OM-06-08 | 4 |
| -10AN | OM-06-10 | 4 |
| 90° Swivel 3/8'' Barb | OB-090-06-06 | 4 |
Inline Sensor Fittings (Optional)
Use these fittings to add an inline sensor to any of the available ports.
| Line Size and Sensor Port Size | Part Number | Qty Required |
| -6AN Male to -6AN Female, 1 x 1/8" NPT Sensor Port | TR-06-02 | 0-4 |
| -6AN Male to -6AN Female, 2 x 1/8" NPT Sensor Port | TR-06-02-B | 0-4 |
| -8AN Male to -8AN Female, 1 x 1/8" NPT Sensor Port | TR-08-02-A | 0-4 |
| -10AN Male to -10AN Female, 1 x 1/8" NPT Sensor Port | TR-10-02-A | 0-4 |
| -12AN Male to -12AN Female, 1 x 1/8" NPT Sensor Port | TR-12-02-A | 0-4 |