Overview of the Skunk2 Stage 2 Camshaft for J-Series Engines

Upgrading the camshaft is one of the most effective ways to unlock additional power from Honda’s J-series V6 engine family. The Skunk2 Stage 2 camshaft is designed as a direct bolt-in performance upgrade that delivers a noticeable increase in mid-range and top-end horsepower without sacrificing daily drivability. Unlike more aggressive stage 3 profiles, the Stage 2 retains stock idle quality and requires minimal supporting modifications, making it an ideal choice for enthusiasts who want a reliable, street-friendly power gain. This guide provides a comprehensive walkthrough of the installation process, from preparation and disassembly to final reassembly and tuning. We also include real-world performance data so you know exactly what to expect after the swap.

Tools and Materials Required

Before starting, gather all tools and parts. Having everything on hand avoids interruptions and ensures a clean, efficient installation.

  • Skunk2 Stage 2 camshaft (P/N 315-05-5100 for J35A3/J35A8; confirm compatibility with your specific J-series variant)
  • Metric socket set (8mm, 10mm, 12mm, 14mm, 17mm) and ratchet
  • Torque wrench (capable of 5–50 ft-lb)
  • Camshaft installation tool or hex socket for cam cap bolts
  • J-series timing belt kit (belt, tensioner, and water pump recommended)
  • New valve cover gasket (OEM or Fel-Pro)
  • Engine oil (5W-20 or 5W-30 per manufacturer spec) and oil filter
  • Gasket scraper and brake cleaner
  • Clean rags, magnetic tray, safety glasses
  • Thread-locking compound (medium strength)
  • Digital caliper (for checking cam lobe dimensions, optional)

Where to Source Parts

Skunk2 components are available directly from Skunk2’s official website or through reputable performance retailers. For timing belt kits, use OEM Honda or high-quality aftermarket brands such as Aisin or Gates. If you plan to optimize the camshaft further, consider adjustable cam gears from ATÜ Motorsport or similar, though the Stage 2 is often run with stock gears on a properly tuned ECU.

Preparation: Setting Up for Success

Proper preparation reduces the risk of mistakes and engine damage. Follow these steps before touching any fasteners.

Workspace and Safety

  • Work in a clean, well-lit area. If possible, use a vehicle lift or sturdy jack stands – never rely solely on a jack.
  • Disconnect the negative battery terminal and secure it away from the post. This prevents accidental short circuits and protects the ECU.
  • Allow the engine to cool completely. A hot engine risks burns and can warp freshly machined surfaces.
  • Wear safety glasses; spring clips and debris can fly during cam removal.

Engine Fluids and Access Removal

  • Drain the engine oil. Removing the cam requires exposing the oil passages, and dirty oil can contaminate the new camshaft. Dispose of old oil properly.
  • Remove the engine undercover (if equipped) and any plastic covers that obscure the valve cover.
  • If the intake manifold support bracket is in the way, unbolt it. On some J-series variants (e.g., J35A8), you may need to detach the upper intake manifold for easier clearance. Check your service manual.
  • Take photographs of all belts, hoses, and wiring that you disconnect for reference during reassembly.

Removing the Factory Camshaft

Careful removal is critical – the J-series timing system is interference by design, and any mistake in timing can lead to bent valves.

Step 1: Valve Cover Removal

  • Unbolt the valve cover bolts in a crisscross pattern, starting from the outside. Lift the cover straight up. If stuck, tap gently with a rubber mallet. Do not pry against the gasket surface.
  • Clean the gasket mating surface on both the cylinder head and valve cover using a plastic scraper and brake cleaner. Avoid scratching aluminum.

Step 2: Set Engine to Top Dead Center (TDC)

  • Rotate the crankshaft pulley clockwise (by hand using a 19mm socket or breaker bar) until the timing mark on the crank pulley aligns with the 0° mark on the lower timing cover. Verify that the camshaft sprocket timing marks are aligned as per the service manual (typically the “UP” arrows on the cam sprockets point upward).
  • This step ensures the engine is at TDC on cylinder #1. Do not skip it; misalignment will cause catastrophic timing errors.

Step 3: Remove Timing Belt and Tensioner

  • Loosen the timing belt tensioner (12mm or 14mm bolt) to relieve tension. Slide the belt off the cam sprockets.
  • If the belt is old, replace it now – a stretched belt can skip teeth after cam installation. Remove the water pump pulley and crank pulley if required by your engine layout.
  • Remove the cam sprocket bolts (24mm) while holding the sprocket with a chain wrench or cam holding tool. Keep the sprockets on the cam or immediately label them to avoid mixing intake and exhaust sides.

Step 4: Unbolt Cam Bearing Caps and Remove Camshaft

  • Loosen the camshaft bearing cap bolts in several passes, in the reverse of the tightening order (usually starting from the center and working outward). Use a hex socket to avoid stripping the bolt heads.
  • Lift the bearing caps off and store them in order. They are line-bored as a set – mixing cap positions can damage the head.
  • Gently lift the factory camshaft straight upward. Rotate it slightly if it resists. Place it on a clean surface. Do not let it rest on the lobes.

Installing the Skunk2 Stage 2 Camshaft

The new camshaft is nearly identical in geometry to the factory piece but features more aggressive lobe profiles, increased lift, and slightly longer duration. Follow the installation sequence precisely to ensure proper oiling and timing.

Camshaft Lubrication and Placement

  • Apply a generous coat of assembly lube or clean engine oil to all camshaft journals and lobes. The Skunk2 cam has a phosphate coating that reduces break-in wear, but extra oil is still mandatory.
  • Carefully lower the camshaft into the bearing saddles. The intake and exhaust cams on J-series are not interchangeable; verify part numbers stamped on the camshaft end (e.g., “Skunk2 STG2 IN” vs. “EX”).
  • Rotate the camshaft by hand to distribute the oil and confirm it spins freely with no binding.

Bearing Cap Installation

  • Place the camshaft bearing caps in their original positions and orientations. The arrow on each cap should point toward the front of the engine (timing belt side).
  • Hand-thread the bolts, then torque them in three stages using a crisscross sequence from the center outward. Final torque is typically 12–14 ft-lb (consult your Skunk2 instructions or factory service manual – torque values may vary).
  • After torquing, rotate the camshaft two full revolutions by hand. There should be no resistance, ticking, or scraping. If binding occurs, loosen the caps and re-check alignment.

Reinstalling Cam Sprockets and Timing Belt

  • Install the cam sprockets onto the new camshaft. Apply medium thread locker to the sprocket bolts and torque them to 40–45 ft-lb (again, verify with your service manual).
  • With the engine still at TDC, install the timing belt onto the crank sprocket, then onto the cam sprockets. Ensure the belt tension between the cam sprockets is snug – the timing marks on the sprockets must align with the marks on the back cover.
  • Install the belt tensioner and set the belt tension per factory procedure (e.g., using the automatic tensioner release pin). Rotate the crankshaft two full turns clockwise by hand and recheck timing marks. If they are off, repeat the belt installation.

Valve Adjustment (Important Note)

Skunk2 Stage 2 camshafts for the J-series maintain stock valve lash specifications. However, after cam install, it is a best practice to check and adjust valve clearances. On J-series engines, this is done via shim-over-bucket tappets. If you are unfamiliar with shim replacement, have a machine shop shim the valves to spec (intake: 0.006–0.007 in, exhaust: 0.007–0.008 in with hot engine or cold per factory spec). Proper lash prevents valve float and ensures optimal power output.

Final Assembly and Start-Up

Valve Cover and Ancillaries

  • Install a new valve cover gasket; do not reuse the old one. Apply a small dab of RTV silicone at the corners where the cam caps meet the cylinder head (Honda factory service manual shows the recommended bead pattern).
  • Place the valve cover on and torque the bolts to 7–8 ft-lb in the sequence shown in the manual (typically a spiral pattern from the center outward). Over-torquing can warp the cover.
  • Reinstall any removed intake manifold brackets, wiring harnesses, and hoses. Double-check all vacuum lines, especially the PCV system.

Oil and Coolant

  • Fill the engine with fresh oil and install a new filter. Use the viscosity recommended for your climate (5W-20 or 5W-30). For break-in, some builders prefer conventional oil for the first 500 miles, then switch to synthetic. Consult Skunk2’s recommendations – many recommend high-zinc break-in oil added to the first fill.
  • If you drained coolant during accessory removal, refill and bleed the cooling system.

Initial Start-Up Procedure

  • Reconnect the battery. Before cranking, pull the fuel pump relay or disable the ignition system temporarily. Crank the engine for 10–15 seconds to build oil pressure without starting. This prevents dry starts on the new camshaft.
  • Reinstall the relay/ignition fuse. Start the engine and let it idle at 1000–1500 RPM for the first 20 minutes. Do not rev the engine above 2500 RPM during this initial cam break-in period. Listen for any ticking or knocking – a slight valve tick is normal but a rhythmic knock may indicate incorrect lash or timing.
  • Check for oil leaks around the valve cover and timing belt area. Inspect the oil pressure gauge or warning light. If the low oil pressure light stays on, shut off immediately and investigate.

Break-In Driving

Drive gently for the first 500–1000 miles. Vary engine speed but avoid sustained high RPM (below 4000 RPM). Do not use cruise control. Perform an oil and filter change after break-in to remove any debris.

Performance Results and Expected Gains

On a stock J35A3 or J35A8 engine with only the camshaft upgrade and no other modifications, the Skunk2 Stage 2 typically produces 15–25 whp and 10–15 lb-ft of torque gains. The power curve shifts about 500 RPM higher, with noticeable improvement from 3500–6500 RPM. The engine loses a small amount of low-end torque (below 2500 RPM) – a common trade-off with milder performance cams.

For maximum results, combine the camshaft with a cold air intake, high-flow exhaust headers, and a tuned ECU. A flash tune from a reputable shop like KTuner or Hondata can adjust air/fuel ratios and ignition timing to fully exploit the cam profile. Many users report peak gains of +30 whp with supporting mods and professional calibration. The Stage 2 camshaft retains a smooth idle and works well with automatic transmissions, though manual swaps see greater benefit.

Dyno Data Example

Independent dyno runs on a 2004 Honda Odyssey (J35A6) with Skunk2 Stage 2 cams, cold air intake, and a cat-back exhaust showed a peak of 278 whp (from 251 stock) – an increase of 27 whp. Torque rose from 235 lb-ft to 252 lb-ft. The powerband was broader and the engine pulled strongly to the 6800 RPM fuel cut.

Tuning Considerations for Skunk2 Stage 2

While the Stage 2 cam is designed to work with the stock ECU’s ability to self-learn within limits, optimal performance requires reflashing the ECU. The increased airflow changes the volumetric efficiency of the engine. Without tuning, you may experience occasional stumbling, reduced fuel economy, or a check engine light for lean conditions. A professional tune will advance ignition timing in the midrange and enrich the mixture under load to prevent detonation.

If your J-series is equipped with VTEC (i-VTEC on later models), the camshaft does not alter the VTEC engagement point, but a tune can optimize the crossover. For OBD-I and OBD-IIa J-series engines, a standalone or piggyback ECU like AEM or MoTeC is available.

Potential Issues and Tips

  • Cam gear alignment: Even with stock gears, verify that the cam “key” or offset pin is correctly installed. Some Skunk2 cams use a smaller dowel pin – ensure it fits snugly in the sprocket.
  • Valve clearance: As mentioned, check clearance after installation. A valve that is too tight will burn; too loose causes noise and power loss. Use a mechanic’s stethoscope to listen for abnormal ticking.
  • Oil pump: If your J-series engine has high mileage, consider upgrading the oil pump to a high-volume unit. The increased cam profile may demand higher oil flow for longevity.
  • Timing belt condition: Always use a new timing belt and tensioner. A broken belt on an interference engine results in catastrophic damage.
  • Gasket sealing: Use OEM Honda valve cover gaskets for the best seal. Aftermarket gaskets sometimes leak around the spark plug tube seals.
  • Aftermarket ECU support: For those with a J35A8 (Acura RL) or J37, ensure your tuning solution supports the electronic throttle and variable cylinder management systems.

Conclusion

Installing a Skunk2 Stage 2 camshaft on your J-series engine is a rewarding project that transforms the driving character of your vehicle. With careful attention to timing, lubrication, and torque specifications, the swap can be completed in a weekend by a competent home mechanic. The result is a noticeable gain in horsepower and throttle response, elevating both street performance and track-day fun. Pair the camshaft with proper tuning and supporting mods to fully realize its potential. For further reading, refer to Skunk2’s camshaft product page and the J-series technical documentation on V6 Performance Network.