4RSTD Stock Cylinder Head MINI R53 | R52 | R50 | Cooper | Cooper S | JCW

STOCK-LEVEL REPLACEMENT
The 4RSTD Cylinder Head is developed for MINI Gen 1 owners in need of a dependable stock replacement. Ideal for daily drivers and lightly modified cars, it’s the perfect solution when the original head is damaged, worn, or missing. Designed to match factory performance, the 4RSTD head is also compatible with basic upgrades like improved intake systems, smaller supercharger pulleys, intercoolers, and free-flowing exhausts. With factory-matched flow and OEM-grade components, it provides reliable performance and drivability, making it a solid foundation for any standard or mildly tuned MINI build.

READY TO PERFORM
Before machining, all cylinder head castings are fully disassembled and meticulously cleaned to remove any residual oil, carbon buildup, or debris from previous use. Each casting then undergoes pressure testing and visual inspection to verify it is free from cracks, warped surfaces, damaged threads, or other potential defects. Only heads that meet our quality standards proceed to the machining stage.

MACHINED FOR RELIABILITY
The machining process begins with replacing all valve guides with our standard-spec guides, engineered for precise fitment and long-term durability. Each guide is then precision-honed to achieve the correct valve-to-guide clearance, ensuring proper lubrication and minimizing premature wear.
Next, the head is fixtured in our in-house Serdi valve seat machine, where all valve seats are cut using a multi-angle profile optimized for the flow characteristics of the standard intake and exhaust valves. After seat cutting, the deck surface is resurfaced to ensure maximum flatness and the correct finish for MLS gasket compatibility. Finally, the cylinder head is thoroughly cleaned to remove any machining debris, preparing it for final assembly.

BUILD TO WITHSTAND
All 4RSTD cylinder heads are assembled using OEM-quality valvetrain components for dependable daily performance. The setup includes standard-size 30.3 mm intake valves and 23.2 mm exhaust valves, paired with OEM valve springs, retainers, and keepers for reliable valve control. Viton valve stem seals are used to ensure long-term oil management.

OPTIONAL CAMSHAFTS
If you're targeting more power from your 4RSTD head package, upgrading the camshaft is essential. We offer several camshaft options to suit different setups. For improved low-end torque and drivability, we recommend the CatCams 1302461. For increased high-RPM performance and maximum top-end power, the CatCams 1302469 is the ideal choice. Both profiles provide noticeable gains in power and torque across the entire RPM range.

CYLINDER HEAD INSTALLATION PACKAGE
Simplify your cylinder head installation by adding our Head Installation Package to your order. To ensure maximum performance and reliability from your 4RevisionEngines build, we supply only high-quality components that protect your investment. Each kit includes the correct fluids, a complete set of gaskets, head bolts, and a fresh set of spark plugs, everything required for a clean and efficient install. Compatible with all MINI Gen 1 engines, this package offers the essential parts at a discounted rate, saving you time, cost, and unnecessary hassle.

WHAT’S INSIDE

Head – OEM machined casting
Intake Valves – OEM 30.3 mm intake valves
Exhaust Valves – OEM 23.2 mm exhaust valves
Springs / Retainers – OEM valve springs and retainers
Valve Guides – Standard-spec valve guides
Valve Seals – Viton valve stem seals
Valve Job – Multi-angle valve job
Deck Surface – Resurfaced for MLS gasket compatibility
Cleaned – Professionally cleaned and prepared for final assembly