RB CNC Welch Plugs & Plug Kits Stainless Steel, Sensor-Ready Design Upgrade your RB engine with precision-engineered CNC machined welch plugs, designed for easy installation, clean sealing, and smart serviceability. Built for engine builders who want reliability, flexibility, and a professional finish. Product Overview These RB CNC welch plugs are purpose-built to replace factory core plugs while adding a major advantage, easy removal and optional sensor integration. Designed with both practicality and performance in mind, they eliminate the frustration of traditional pressed plugs. Key Features ✔ CNC Machined for RB Blocks– Precision fit for RB20, RB25, Neo, RB26, and RB30 blocks. ✔ Blind Thread Design for Easy Removal– No more drilling or prying out plugs– Simple extraction when required ✔ Dual Thread Options– Small plugs: M6 thread (removal only)– Large plug: M10x1.0 thread (ideal for pressure sensors) ✔ Integrated Datum Mark for Sensor Setup– Clearly marked drilling point on rear of plug– Allows accurate machining to expose coolant gallery pressure– Install plug in your preferred location for clean sensor placement ✔ Shouldered Design for Easy Fitment– Positive stop for consistent install depth– Flush finish against the block– Ideal for use with retaining/sealing compounds ✔ CNC Machined from 300 Series Stainless Steel– Corrosion-resistant– High strength and long service life Performance & Practical Benefits Eliminates guesswork with built-in datum reference Enables clean, professional coolant pressure sensor integration Prevents damage during removal compared to factory plugs Improves sealing reliability with shoulder and compound compatibility Ideal for performance builds, race engines, and detailed restorations Configuration Options Full RB Welch Plug Kit – Complete set for engine build or refresh Single Large Plug (M10x1.0) – Perfect for dedicated pressure sensor install Important Notes Small plug threads are for removal purposes only When using the sensor feature, drilling/machining is required Ensure surrounding components are considered before selecting install location Perfect For 🏁 Engine builders wanting serviceable, high-quality plugs🔧 RB performance builds and race engines📊 Tuners adding oil pressure sensor ports🚗 Clean, professional engine bay finishes Advanced Engine Protection Capability Integrating a coolant pressure sensor into your ECU strategy adds a critical layer of engine protection. By monitoring coolant system pressure in real time, the ECU can detect failures long before the driver is aware, including split hoses, leaking head gaskets, or a failing water pump. A head gasket failure, in particular, can escalate rapidly and lead to hydraulic lock, potentially bending a connecting rod and destroying an otherwise healthy engine. With a pressure sensor in place and configured into your ECU’s safety protocols, the system can trigger warnings, cut boost, or shut the engine down before catastrophic damage occurs. The M10x1.0 thread used in the large plug is a widely adopted standard, compatible with many Bosch and similar pressure sensors, making integration simple and effective for modern performance builds. Why Builders Choose These Because they solve real problems, easy removal, clean install, and built-in sensor capability, all in a premium stainless, CNC-machined package designed for serious RB engines. Installation Guide Sensor Preparation (Optional – Large Plug Only) If installing a plug for use with a pressure sensor: Using a drill bit larger than 6mm, drill through the rear of the plug at the datum point. Test fit your sensor to ensure a snug and accurate fit. If required, open the rear of the plug further using an 11mm–12mm drill bit (thread-size clearance). Deburr thoroughly and clean the plug to remove all swarf and sharp edges. Plug Installation Place the welch plugs in a freezer for 20–40 minutes prior to installation. Ensure the engine block is at room temperature (above 20°C). Clean the welch plug bores in the block thoroughly, remove all debris, corrosion, paint, and oil residue. Apply a retaining/sealing compound to the inner edge of the plug shoulder. Carefully align the plug with the bore. Fitting Method Use 5–6 layers of masking tape stacked together as a cushioning pad and gently drive the plug into place,OR Install a sacrificial bolt into the threaded hole and tap the bolt head to seat the plug evenly. Ensure the plug seats firmly against the shoulder for a flush, secure fit. Important Notes Take care to select plug locations that do not interfere with other engine components. Always confirm clearance for sensors, fittings, and surrounding hardware before final installation. Do not strike the plug directly with a hammer—always use a buffer or bolt method to avoid damage.Upgrade to CNC precision with built-in sensor capability.⚙️ Add to Cart Now and future-proof your engine.
