The JAM Stage 2 cylinder head package is designed for use on larger displacement engines (2.2, 2.3) higher boost and higher RPM applications. It utilizes larger +1mm valves and custom port work to increase flow by up to 15%. The included manganese bronze valve guides offer lower friction, better valve control, enhanced airflow and a higher tolerance to heat produced by endurance, higher boost and RPM. With high pressure Kiggly springs, this cylinder head is recommended for applications seeing up to 25psi boost. For 2.0L applications with higher than 25psi, choose the Manley dual spring upgrade to allow proper valve control at higher boost. For 2.3L applications with higher than 25psi we recommend going with our Stage 3 cylinder head. Please call or email with any questions regarding your application.
Available for 6 and 7 bolt DSM and Evo 4-9. Good core is required.
The following procedures are performed to your cylinder head:
- Complete disassembly and cleaning
- Visual inspection and evaluation
- Pressure test to reveal any cracks in the casting
- Remove stock guides
- Perform stage 1 por work which includes port match, blend the bowls and smooth casting flash and imperfections
- Install a set of high performance manganese bronze guides and hone to size
- Machine seats to larger ID to fit +1mm valves
- Valve seats are machined in-house to enhance airflow
- Valves are machined and back-cut to compliment the seats and enhance airflow
- Valves are hand-lapped to the seats to maximize sealing
- Valve heights are set to within +/-.001″
- Valve spring pressures are checked and set to our specifiations based on your application
- The deck surface is resurfaced to RA40 (suitable for use with MLS gaskets)
- All components are final washed and the head is assembled with new Viton premium valve seals
The following parts are included:
- JAM custom valves, +1mm oversize, nitride coated.
- Manganese bronze valve guide set
- Kiggly racing high pressure beehive springs with titanium retainers
- Premium Viton valve seals