Designed specifically for Mitsubishi 4G63 twin-cam engines, the HRB 4G In-Car Valve Spring Tool allows you to replace valve springs without removing the cylinder head—saving serious time during builds or servicing. Whether you’re upgrading to stiffer springs for a performance setup or replacing worn components in a street engine, this tool makes the process safer, faster, and more precise.

Developed in a professional engine-building environment, this tool is engineered to fit the tight confines of the 4G63 EVO 1-9 head while providing smooth, controlled spring compression with maximum visibility and access.

Key Features:

• Billet 6061 aluminium body for lightweight strength
• Billet stainless steel retainer cup with large cutaway for improved keeper access
• Bronze bush for ultra-smooth compression
• ¼-inch drive threaded rod – compatible with hand tools or drill drivers
• Captive design – tool stays together during use
• Anodised for corrosion resistance and long life
• Supplied with bolts for direct fitment on 4G heads

Why Choose the HRB 4G In-Car Valve Spring Tool?

Traditional valve spring work on 4G engines often means pulling the head. This tool eliminates that step, allowing fast, in-place spring changes while maintaining engine assembly. Trusted by professional engine builders and DIYers alike, it’s a game-changer for anyone working with Mitsubishi EVO 1–9 4G63 platforms.

For tips and tricks for your 4G in car valve spring job check out this blog:

How to Remove Valve Springs Without Removing the Head (And Why We Built Better Tools for the Job)