Upgrading your D-series engine with a Skunk2 camshaft kit is one of the most effective ways to unlock real horsepower without going fully built. The D-series family — found in countless Honda Civics, Del Sols, and CRXs — is known for its reliability and high-revving nature, but its factory camshaft leaves a lot of potential on the table. A Skunk2 camshaft kit, featuring a performance camshaft, valve springs, and retainers, can add a reliable 15–20 horsepower to the wheels when properly installed and tuned. This guide takes you through every step of the installation process, from prep work to final tuning considerations, so you get the most out of your upgrade.

Understanding the Skunk2 Camshaft Kit

Skunk2 offers a range of camshaft kits for the D-series, typically named after their profile — Stage 2, Stage 3, or Tuner series. The kit includes a billet camshaft, dual valve springs with titanium retainers, and often a valve seal set. The camshaft’s increased lift and duration allow more air and fuel into the cylinder, while the upgraded valvetrain ensures the parts can handle the extra rpm. Expect a noticeable change in the engine’s powerband: more top-end pull, a lumpier idle, and a broader torque curve when paired with proper intake and exhaust mods.

Tools and Materials Needed

Having the right tools on hand before you start saves time and prevents frustration. Here’s a complete list of what you’ll need:

  • Skunk2 Camshaft Kit (cam, springs, retainers, keepers and seals)
  • Socket set (metric sockets: 8mm, 10mm, 12mm, 14mm, 17mm, 19mm)
  • Torque wrench (range 0–60 ft-lbs, preferably split beam)
  • Timing belt tool (or a long screwdriver to hold the tensioner)
  • Valve spring compressor (for removing old springs if you’re swapping them)
  • Gasket scraper and plastic razor blades
  • Engine oil (5W-30 or 10W-30, plus assembly lube)
  • Coolant (Honda Type 2 or equivalent)
  • Clean rags, degreaser, brake cleaner
  • Safety goggles and mechanic’s gloves
  • Feeler gauge set (for valve lash adjustment, if cam requires)
  • Engine Hoist? Not needed — the cam can be replaced with the engine in the car, though removing the radiator and fan assembly gives more room.

Preparation: Getting the Engine Ready

Clean workspace and proper safety measures are critical. Park the car on level ground, disconnect the negative battery terminal, and let the engine cool completely. Follow these preparation steps:

  • Drain the engine oil and replace the filter if due. Remove the oil pan if you plan to inspect the oil pick-up later; otherwise, just drain.
  • Drain the coolant from the radiator drain plug and the engine block (optional but recommended to avoid spills when removing the intake manifold).
  • Remove the intake manifold and throttle body — this gives access to the valve cover and camshaft area. Mark and bag bolts.
  • Remove the valve cover and set aside. The gasket should be replaced.
  • Remove the timing belt upper and lower covers to expose the camshaft sprocket and timing belt.
  • Rotate the crankshaft to Top Dead Center (TDC) on cylinder #1. Align the timing mark on the crankshaft pulley with the pointer on the timing cover, and check that the cam sprocket’s TDC mark aligns with the cylinder head surface. If not, rotate one full revolution.

If your D-series has a distributor (most do), you may also need to remove the distributor to access the camshaft cap bolts at the rear of the head. Keep track of the distributor orientation — note the rotor position so you can reinstall without losing ignition timing.

Removing the Old Camshaft

With the engine at TDC and timing belt exposed, proceed to remove the stock camshaft.

1. Release the Timing Belt Tension

Use a 14mm socket to loosen the timing belt tensioner’s mounting bolts. Rotate the tensioner to relieve belt tension, then temporarily tighten one bolt to hold it in the relaxed position. Slide the timing belt off the camshaft sprocket. Do not rotate the crankshaft while the belt is off — the valves and pistons could collide.

2. Remove the Camshaft Sprocket

Hold the camshaft sprocket with a sprocket holder tool (or a heavy screwdriver between the sprocket’s holes) and loosen the center bolt. The bolt is typically torqued to around 27 ft-lbs. Remove the bolt and pull the sprocket off the camshaft.

3. Unbolt the Camshaft Caps

The camshaft is held by the cam caps — usually 6 or 7 caps depending on the head design. Caps are numbered and must go back in the same position and orientation. Use a 10mm socket and loosen the bolts in a crisscross pattern, a few turns at a time, to prevent bending the camshaft. Remove all caps and note their locations.

4. Lift Out the Old Camshaft

Carefully lift the camshaft straight up from the head. If it’s stuck, gently tap it without damaging the bearing journals. Set it aside.

Installing the Skunk2 Camshaft and Valvetrain

If your Skunk2 kit includes performance valve springs and retainers, now is the time to install them. Do this step if you want to rev higher or are using a cam with aggressive lift (anything over .500” lift).

Replacing Valve Springs (if needed)

Remove the spark plugs for easier turning. Use a valve spring compressor that fits D-series heads. Compress each spring, remove the two small keepers, then remove the retainer and spring. Install the new Skunk2 spring and retainer assembly, compress, and install the keepers. Apply a dab of grease to keepers to hold them in place. Repeat for all valves.

Installing the New Camshaft

Clean the cam bearing journals in the head and the caps. Apply a generous amount of assembly lube or clean engine oil to the bearings and the cam lobes. Carefully lower the new Skunk2 camshaft into place — align the cam’s keyway with the sprocket drive pin if required.

Torquing Cam Caps

Install the cam caps in the correct order and orientation (arrows pointing toward the timing belt side on most D-series heads). Hand-tighten all bolts, then torque in three steps using a crisscross pattern. Final torque is typically 84 inch-pounds (7 ft-lbs) for the 8mm bolts — check your Skunk2 instructions as some kits require a specific sequence and torque value. Overtightening can distort the cam tunnel.

Installing the Sprocket and Timing Belt

Slide the cam sprocket onto the camshaft. The sprocket’s keyway should align with the cam’s drive pin. Install the center bolt and torque to 27 ft-lbs while holding the sprocket. Now route the timing belt over both sprockets, ensuring the belt’s teeth engage properly. Reinstall the tensioner and apply tension according to factory spec — typically rotate the crank two full turns and then check the belt deflection.

Reassembling the Engine

With the new camshaft installed and timing set, it’s time to put everything back together.

  • Install a new valve cover gasket and reinstall the valve cover. Torque the 10mm bolts to 84 inch-pounds in sequence from center outward.
  • Reinstall the timing belt covers and the crankshaft pulley (if removed).
  • Reinstall the intake manifold with a new gasket. Torque nuts to 16 ft-lbs in a crisscross pattern.
  • Refill engine oil (about 3.5-4 quarts depending on D15/D16). Use a high-quality synthetic blend or full synthetic.
  • Refill coolant using the proper bleed procedure.
  • Reconnect the battery and check for any loose wires or hoses.

Tuning: The Critical Step for Power and Safety

Installing a Skunk2 camshaft without tuning is like buying a supercar and driving with the parking brake on. The stock ECU cannot compensate for the altered VE (volumetric efficiency) and cam timing. At minimum, you need a reflash or reprogrammed ECU. For full control, a standalone engine management system (like Hondata S300, Neptune, or a Megasquirt) is recommended.

A proper tune will adjust the fuel maps (injector pulse width) and ignition timing to match the cam’s power range. Expect to spend a couple of hours on a dyno with an experienced Honda tuner. Without tuning, you risk lean conditions, misfires, and even engine damage. Some mild Stage 2 cams may run okay with a “base map” from a reputable tuner, but a custom tune is always safer and yields more power.

Valve Lash Adjustment

Skunk2 performance cams often require a wider valve lash than stock. Check the specifications included with your cam — common D-series cam lash settings are .006” to .008” on intake and .008” to .010” on exhaust. Adjust with a feeler gauge by turning the adjusting screw on each rocker arm. This step is crucial for quiet operation and preventing valve float.

Final Checks and Testing

Before celebrating, perform these checks:

  • Look for fluid leaks at the cam caps, valve cover gasket, and timing belt cover seams.
  • Verify timing marks after rotating the engine by hand two full turns. The crank and cam marks should still align.
  • Start the engine and listen for unusual noises — metallic tapping (valve lash too tight), a knocking from the cam chain area (timing off), or a rough idle (air leaks or tune needed). Let it idle for 10 minutes, then check for leaks again.
  • Take a short test drive under light load to confirm the engine feels responsive and smooth. Gradually increase rpm to 5000-6000 in second gear to feel the power gain.
  • Retorque the cam caps after 500 miles as the assembly lube breaks in.

Expected Power Gains and Supporting Mods

A Skunk2 cam alone will not deliver the full 15-20 hp unless paired with a free-flowing intake, header, and exhaust. Consider adding a cold air intake, a 4-2-1 or 4-1 header (2.5” collector), and a 2.5” exhaust system. A bigger throttle body (70mm) and port-matched intake manifold also help. With a good tune and bolt-ons, the D-series can reach 130-150 whp — impressive for a 1.6-liter engine.

Troubleshooting Common Issues

Engine won’t start or runs poorly: Check ignition timing and cam/crank sensor signals. Ensure the distributor is not 180° off. Re-verify TDC and cam sprocket orientation.

Loud ticking: Recheck valve lash. If it persists, the rocker arms may need replacement if they’re worn.

Low power: The ECU may be running in “limp” mode if a sensor is unplugged. Also, ensure the new cam’s intake centerline is set correctly (most Skunk2 cams use a straight-up install).

Additional Resources

For more detailed specs on the exact cam kit you purchased, visit the Skunk2 official website and download the product instructions. Active forums like Honda-Tech have hundreds of D-series build threads with real-world tips. If you need custom tuning, consider services from KP Engineering or local shops that specialize in Honda ECUs.

Conclusion

Installing a Skunk2 camshaft kit on your D-series engine is a rewarding project that gives you a tangible horsepower increase and a more aggressive engine character. By following this detailed guide — from tool preparation through tuning — you can complete the swap in a weekend with confidence. Pay close attention to torque specs, timing alignment, and valve lash, and don’t skip the tune. Your D-series will reward you with a stronger pull to redline that makes every drive more exciting. Take your time, work clean, and enjoy the results.