Scarlett’s Solutions Surface Temperature Sensor – 3/8” Bolt-On

Designed for high-performance applications where traditional coolant-based sensing isn’t an option or to be used as adjunct, the Scarlett’s Solutions Surface Temperature Sensor delivers reliable, accurate readings in dry environments. This compact unit slips over a 3/8” bolt and captures metal surface temperatures, making it ideal for cylinder heads, intake manifolds, dry blocks, and other areas.

This can be used to input cylinder head temperature as the coolant input in your ECU. 

Key Features:

• Bolt-on Design: Fits snugly around any 3/8” bolt for secure contact and fast heat transfer

• No Coolant Required: Perfect for dry-block applications, air-cooled setups, or supplemental temperature monitoring

• Easy Installation - two wires along with a scaling sheet and illustrations of scaling in fueltech and Holley software

• Two connectors available (select below)

1. DTM 2-Pin Connector: Weatherproof and motorsport-proven for easy integration into existing harnesses. Includes mating connector and solid barrel pins. Stamped pins available upon request.

2. GM temperature sensor connector, designed to plug in to coolant temp sensor on most harnesses. 

A smart solution for accurate temperature data without plumbing a coolant sensor—engineered with the same uncompromising standards as the rest of the Scarlett’s Solutions sensor lineup.

Installation Note:

For optimal performance and longevity, this sensor must be mounted and routed carefully to prevent heat damage. Ensure the wiring is secured away from direct contact with cylinder heads, engine blocks, exhaust components, or other high-heat surfaces. Use proper thermal sleeving or standoffs where necessary to protect the harness and electrical connection. This sensor is not designed for exposure to temperatures over 400 degrees.