Our top line cylinder head set for big turbo applications making over 500whp. We start with new factory castings which are ported on a 5-axis CNC mill. Port design is a culmination of 20 years of Subaru tuning experience and is intended to provide an excellent balance between low/mid-range driveability and top end flow. Ports are designed around a +1mm valve size and carefully blended into the valve seat. Bronze guides are fitted to provide excellent heat transfer and durability under extreme conditions. We use Ferrea competition series valves for their superior quality, design, and materials. An inconel alloy exhaust valve is used for durability at extreme temperatures. Ferrea dual valve springs, titanium retainers, and billet valve locks keep the valves moving in the right direction at up to 10,000rpm. Kelford S2 camshafts ("272" duration) are standard but other options can be provided.
Fully assembled from all new components. Valve clearances are set and heads are ready for installation. Heads can be machined for use with oversized head studs, either 12mm, 1/2in or 14mm for an additional cost (please specify size when ordering).
Currently heads are made to order with a 3 to 4 week delivery time.
| Part No. | Description | Application | Price Ea. | Add to Cart |
|---|---|---|---|---|
| RCH-C2504 | RalliSpec Big Valve B25 Cylinder Head Set w/ Cams | MY04-06 | $6695.00 |  |
| RCH-C2507 | RalliSpec Big Valve V25B Cylinder Head Set w/ Cams | MY07 | $6825.00 | |
| RCH-C2508 | RalliSpec Big Valve W25 Cylinder Head Set w/ Cams | MY08+ | $6695.00 | |
| RCH-C2509 | RalliSpec Big Valve D25 Cylinder Head Set w/ Cams | MY08+ | $6725.00 | |
| RCH-C2519 | RalliSpec Big Valve N25 Cylinder Head Set w/ Cams | MY19+ | $6795.00 | |
| RCH-14HS | Machine Set of Heads For Oversized Head Studs | $150.00 | |
