Ease of Fitment Guide
• Cylinder head studs manufactured using "Aircraft Grade S99 High Tensile Steel" to WRC specification.
• Precision rolled threads.
• Cylinder head stud thread pitch (Block End): M14X2.
• Cylinder head stud thread pitch (Cylinder Head end): 9/16 - 18 UNF.
• Cylinder head stud length: 197mm.
• Supplied in the kit are:
• x12 RCM 14mm head studs.
• x12 ARP 9/16" 8740 Chromoly 12pt nut
• x12 ARP 9/16" 8740 Chromoly washer
• 1x Sachet of assembly lube and fitting guide for a comprehensive install.
• To allow fitting of the RCM 14/14mm Head stud kit your engine block must be re engineered to accept the larger studs used in this kit. RCM can carry this work out for you at additional cost (see part number RCM237 or contact us for more details).
• Due to the increased diameter of the cylinder head stud machining is required to the cylinder heads. The original head bolt passages must be drilled out to a larger diameter in order for the 14mm stud to pass through. RCM can carry out this process for you if required (see part number RCM603 or contact us for more details).
• Non RCM manufactured head gaskets used alongside this kit will require slight modification using our tapered reamer tool (See part number RCM910).
• 4x RCM658 modified head location dowels are required when using this kit (Sold separately).
• Huge increase in tensile strength and yield when compared with the OE head bolts.
• Massively increased clamping load for big bhp applications.
• Eliminates cylinder head lift at high levels of boost.
• Supplied with ARP high tensile nuts, washers, RCM assembly lube and installation guide.
• As used in RCM Gobstopper I + II Time Attack race cars.
• Made in the UK from high tensile aircraft grade S99 steel to WRC spec.
• Precision rolled threads for maximum strength.
Suitable for all EJ20/22/25 series block cases.
If you are unsure of fitment then please check your engine code or contact our sales department.