LF4/LF3 engines start to experience valve float around 6,000 rpm at high boost levels. Stronger valvesprings will eliminate this problem, in addition to allowing larger aftermarket camshafts to be run safely. Both the Mace Stage 1 and Tapout Stage 2 valve springs and retainers are drop in replacements that require no modification to the cylinder heads, and will reuse the stock valve stem seals
Mace Stage 1 valve spring kit is suited for high revving applications with OEM or the Mace Stage 1 higher duration camshafts, and completely eliminates all traces of valve float. This kit includes an ovate wire, gas nitride treated beehive spring with light weight titanium retainers. OEM specifications are 56 to 61 pounds of seat pressure closed and 134 to 149 pounds open. These springs are rated at 90 lbs. seat pressure at installed height and 230 lbs. @ 0.500” maximum lift.
Tapout Stage 2 valve spring kit was developed in conjunction with Cal Smith of Caddy Issues, and will work perfectly along with Tapout Stage 2 camshafts. They will also work fine with OEM or Mace Stage 1 camshafts. These are manufactured in the U.S., using the highest quality components we can source. Custom shims are included for seat pressure of 107 lbs. at installed height, 251 lbs. @ .433” lift (OEM camshafts) and 266 lbs. @ .485” lift (Tapout Stage 2 camshafts).
We recommend several special tools for your valve springs swap, all of which are readily available online.
- EN-48313 timing chain retention tool
- EN-39313 spark plug port adapter
- EN-46106 flywheel holding tool
- EN-46110 valve spring compressor tool