Nissan RB20/RB25/RB26 Cylinder Head Oil Drain Kit – Billet Rear Welch Plug Replacement

🛠️ Solve Your RB Oil Drain Issues — Finally

The first real solution for rear oil drainage on the RB20, RB25, and RB26 heads — designed by engine builders, for engine builders.

Getting oil back to the sump from the RB head has always been a challenge, especially under sustained RPM or boost. Factory setups offer no rear drain provision — until now. This billet drain kit fixes the problem without modification or drilling.

Engineered and manufactured in-house by Milton Engine Developments, this T6 billet aluminium drain replaces the factory welch plug at the rear of the head, improving oil return while suppressing blow-by through the breathers.

💡 Why Install a Rear Head Drain & Breather Suppression Kit?

• No-drill installation — replaces factory welch plug
• Improves oil return to sump from rear of head
• Reduces crankcase oil spray and breather push-out
• Essential for high-performance RB20/25/26 builds
• Eliminates a common oil flow weakness in RB series engines

✅ Key Features:

• Billet T6 aluminium construction, CNC-machined in South Australia
• Push-in fitment — no cylinder head modifications required
• Includes all required -8 fittings
• Multi-port drain design suits both sides of the head

📦 Fitment:

• Nissan RB20
• Nissan RB25
• Nissan RB26

🇦🇺 Australian Made by Milton Engine Developments

All components are engineered and CNC-machined in-house in South Australia — trusted by engine builders nationwide.

📦 Stock & Support

In stock and ready to ship from Adelaide. Need help with fitment or unsure which RB drain you need? Contact us — we’re here to assist.