Setup and Runout Checks Before Valve Refacing: Best Practices

Once valves are cleaned and inspected, the difference between an average and an excellent reface comes down to setup discipline. Proper fixturing, runout verification, and wheel prep ensure you remove the minimum material while achieving concentricity, correct angles, and surface finish that seals. Here’s a practical, step-by-step guide to the best practices you should perform immediately before grinding.

Objectives of pre-grind setup

  • Clamp the valve dead true to the grinder’s spindle axis.
  • Verify stem and face runout to predict cleanup.
  • Confirm wheel geometry and dressing to the required angle and finish.
  • Minimize stock removal by optimizing initial contact.

1) Verify the valve’s condition one last time

Before you mount anything, do a quick recheck that impacts setup accuracy and safety.

  • Stem and tip:
    • Ensure no residual burrs at keeper grooves or tip mushrooming that would affect collet fit.
    • Lightly stone any tiny burrs by hand; re-measure if you touched the stem.
  • Cleanliness:
    • Wipe stem with a lint-free cloth and solvent. Any film will alter clamping friction and concentricity.
  • Identification:
    • Keep intake and exhaust grouped; set expected angles and margin targets accordingly.

2) Select and verify the correct collet or chuck

Concentric workholding is everything.

  • Collet selection:
    • Choose the smallest collet that accepts the stem smoothly without forcing.
    • The stem should seat with uniform contact; avoid any “two-point” feel indicating taper mismatch.
  • Collet condition:
    • Inspect for nicks, debris, or glaze. Clean with solvent and a soft brush; never oil the gripping surfaces.
    • Test grip with a known-straight gauge pin near the valve’s stem size to check for uniform clamping.
  • Alternative workholding:
    • If using a chuck, verify jaws are clean, parallel, and free of dings. Lightly burnish jaw steps if needed.

Tip: Rotate the collet 120° at a time with the same valve and check indicator readings. Large variation by collet orientation points to collet wear or contamination.

For Kwik-Way SVSII Deluxe Users
  • Ensure the chuck saddle bearing capped oilers have been oiled with 30 wt. motor oil.
  • Verify the chuck runout is good by using a dial indicator and a known machined straight shaft like a seat grinding pilot. (if not you need to clean your chuck)
  • Lightly lubricate the chuck collar area with Automatic Transmission Fluid (ATF).
  • Set the valve stop located inside the chuck body.

3) Align and preload in the workhead

  • Axial location:
    • Seat the stem fully and consistently. A change in stick-out alters wheel contact point and can affect angle/finish.
  • Workhead spindle health:
    • Spin by hand; feel for roughness or play. Any axial/radial looseness must be corrected before proceeding.
  • Clamp torque:
    • Tighten consistently—too light risks slip, too heavy can distort thin stems.

4) Dial-indicator runout checks (stem and face)

Runout checks confirm you’ll grind concentric to the stem axis and predict cleanup.

  • Stem runout in the setup:
    • Place a dial indicator on a clean mid-stem surface.
    • Rotate the workhead slowly. Target total indicated runout (TIR) ≤ 0.0005–0.0010 in (0.013–0.025 mm), depending on equipment class and valve size.
    • If TIR is high: clean and reseat, try a different collet, or rotate the valve 180° to rule out stem irregularity.
  • Seat-face pre-check:
    • Place the indicator on the seat face near the margin. This provides a quick sanity check of concentricity to the clamped stem.
    • Large face TIR with low stem TIR suggests a bent head or previous off-center grind; expect more cleanup.

Note: If the stem itself has measurable runout (bent), you can still reface, but predict greater stock removal to achieve a concentric face—and weigh margin impact before proceeding.

5) Wheel selection, dressing, and geometry verification

The wheel is your cutting tool—treat it like one.

  • Wheel type:
    • Use the manufacturer-recommended abrasive and grade for steel vs. stainless, intake vs. exhaust, and hardened faces.
  • Dressing:
    • Dress the grinding wheel per your machine's owners manual.
    • Use a sharp, rigid diamond dresser. Take a consistent, light pass to remove glaze and restore a flat, open cutting surface.
  • Face geometry:
    • Verify with a protractor, angle block, or built-in gauge that the dresser setting matches your target angle.
    • For multi-angle systems, ensure only the intended face angle is presented to the valve.
  • Surface finish readiness:
    • A freshly dressed wheel cuts cooler and truer. If finish is too coarse, a light “sparkle” re-dress or a finishing pass will refine the surface.

Best practice: Dress immediately before critical valves or batches. Wheel glaze increases heat, chatter, and runout imprinting.

6) Workhead angle and reference checks

  • Workhead angle:
    • Set the workhead to the valve face angle (e.g., 45°). Lock it securely; check the detent is fully seated if equipped.
  • Zeroing reference:
    • Confirm that your angle reference is calibrated. If the grinder allows, check against a known-good angle standard.
  • Travel and stops:
    • Ensure smooth travel to and across the valve face without binding. Set stops so you don’t dwell off the edge and create a lip.

7) Coolant and cleanliness prep

  • Coolant:
    • If using coolant, verify flow and cleanliness. Contaminated coolant recirculates grit, affecting finish and wheel life.
  • Splash and swarf control:
    • Position guards and baffles. Keep the work area free of loose grit that can migrate to the chuck or stem.
  • Wipe-down:
    • Right before the first contact, wipe the valve face and stem again. Small abrasives can wedge under a collet and induce runout.

8) Blue-check for contact prediction

Predict cleanup and reduce unnecessary stock removal.

  • Layout dye:
    • Apply layout blue or marker to the valve face. Gently kiss the wheel to transfer a contact pattern.
  • Read the pattern:
    • Even, full-width contact indicates a good initial setup.
    • A heavier mark on one sector means eccentricity; recheck clamping and indicator readings.
    • If contact is very near the margin edge, ensure your margin will remain in spec after cleanup and re-verify your angle settings.

9) Spindle warmup and stability

  • Warmup:
    • Run the grinder for a minute to stabilize bearings and motor speed, especially in cooler shops.
  • Vibration check:
    • Listen and feel for vibration. If present, re-balance the wheel or redress. Vibration prints onto the finish.

10) Final TIR check at grinding angle

After the machine is at temperature and the wheel is freshly dressed:

  • Re-check stem TIR in the working position.
  • If your grinder allows, check face TIR again with the indicator aligned to the grinding plane.
  • Confirm stock plan:
    • Estimate cleanup based on the blue-check and TIR. Aim for minimal removal to preserve margin and heat path.

Keep in mind: The less material removed, the better the valve job.

11) Safety and process-ready checklist

  • PPE: Eye protection, no loose clothing/gloves near rotating parts.
  • Guards in place and secure.
  • Wheel: No cracks, correct spec, freshly dressed.
  • Workholding: Correct collet/chuck, clean, proper clamp torque.
  • TIR within target.
  • Coolant/air: Flow verified, directed correctly.
  • Stops and travel: Set to avoid edge dwell and over-travel.

Notes for Kwik-Way SVS II Deluxe users

  • Collet system:
    • The accurate, fast-clamping collet design helps achieve low TIR with minimal fuss. Keep the collet and taper scrupulously clean for repeatability.
  • Dressing:
    • Use the integrated diamond dresser to set and maintain the 45° face angle. A quick dress between valves maintains finish consistency.
  • Workhead stability:
    • The rigid workhead and smooth traverse help reduce chatter, enabling fine finishes that seal quickly with minimal or no lapping.

Troubleshooting quick hits

  • High TIR that changes with collet rotation:
    • Collet wear or contamination. Clean or try a different collet.
  • High TIR that follows the valve:
    • Bent stem or irregular stem diameter. Consider replacement or expect higher stock removal; recheck margin.
  • Chatter or poor finish on first contact:
    • Redress wheel, reduce infeed, verify spindle warm, and confirm workhead lock tightness.
  • Valve slips in cut:
    • Increase clamp torque modestly, clean stem/collet, verify coolant isn’t flooding the clamping interface.

By following these setup and runout best practices, you’ll grind truer valves with less heat, less material removal, and better sealing results. A disciplined pre-grind routine pays off in consistent quality and faster final assembly.