Project Do It All S13, Assembling the Bulletproof SR20DET Cylinder Head!

Here is how the double guide shim fits once the rocker is modded.  To keep the rocker level, we fitted the valves, facing off the stem in a valve grinding machine until the stems were equal in height.  This mod considerably improves the rocker arm retention.

Finally, we used the hydraulic lash adjuster from a 2000-2002 roller cam SR20 as found in the early B15 and P11.  This lash adjuster resists collapse and also helps prevent the rockers from jumping off.  The plunger of the lash adjuster has a much smaller pivot hole and a bigger fill hole than the original parts.  This helps keep more oil pressure in its body.

The fill port seems to have a check valve right in the port.  This also probably helps keep pressure in the lash adjuster’s body.   We are hoping these mods make the issue of rocker fall out a nonissue.

We used Jim Wolf Technology valve springs.  These springs are frequency-matched to their cam profiles, allowing JWT to have more aggressive valve events for more power while still keeping relatively low seat pressure for longer valve train life and less friction.  We had CTP cryogenics cryo treat the springs and then WPC treated them for longer fatigue life.

We used Jim Wold Technology C1 camshafts.  The C1 has a high lift of .476″ and a low duration of 264 degrees with a lot of area under the curve for a maximum powerband width.  This is way more lift than a typical JDM brand cam.  This means the JWT cam will have more power and torque over a wider range while having a smoother idle and better driveability than your typical larger 272 or so JDM cam.  We sent our cams to CTP Cryogenics for cryo treating to stress relive them and to improve wear, then had them WPC treated for longer life and less friction.