Introduction

The Skunk2 Stage 2 camshaft is one of the most popular upgrades for B-series Honda engines, offering a proven 20–25 horsepower gain when paired with proper supporting modifications. Unlike milder cam profiles, the Stage 2 delivers strong mid-range and top-end power without sacrificing too much low-end torque, making it ideal for street-driven performance cars, autocross, and track days. However, achieving those gains requires careful installation, correct timing, and ECU tuning. This guide walks you through the entire swap process, from tool preparation to final tuning considerations, so you can confidently install your Skunk2 Stage 2 cam and unlock the full potential of your B-series engine.

Tools and Materials Needed

Having a complete set of tools and replacement parts on hand will save time and prevent frustrating trips to the auto parts store. Below is a comprehensive list for the camshaft swap:

Essential Tools

  • Socket set – 10mm, 12mm, 14mm, 17mm, and 19mm sockets (both shallow and deep)
  • Torque wrench – 1/2-inch drive, capable of 20–100 ft-lbs range
  • Camshaft installation tool – a cam gear holding tool or adjustable spanner wrench
  • Timing belt tensioner tool – hex key or T-handle for loosening/tightening the tensioner
  • Valve cover gasket scraper – plastic or metal scraper for cleaning old gasket residue
  • Magnetic parts tray – to keep bolts organized
  • Feeler gauge set – for checking/adjusting valve lash (if your cam requires it)
  • Shop rags and brake cleaner – for cleaning cylinder head and cam journals

Replacement Parts and Consumables

  • Skunk2 Stage 2 camshaft – ensure it matches your B-series variant (B16, B18, B20, etc.)
  • Timing belt kit – includes belt, tensioner, and idler pulley (replace as a set)
  • Valve cover gasket – OEM Honda or equivalent quality gasket
  • Spark plug tube seals – replace if they are hardened or leaking
  • Engine oil and filter – 5W-30 or 10W-30 high-quality synthetic
  • RTV silicone gasket maker – for the valve cover half-moon seals and corners
  • Antifreeze/coolant – if you need to drain coolant (recommended for easier timing belt access)

Preparation and Safety

Before you turn a single bolt, take these important preparatory steps to ensure a smooth and safe installation.

1. Let the Engine Cool Completely

A hot engine can burn you and make metal components expand, causing inaccurate timing measurements. Allow the engine to sit overnight or at least several hours after the last drive.

2. Disconnect the Battery

Disconnect the negative terminal of the battery to prevent any accidental short circuits or ECU damage during work.

3. Clean Your Workspace

Dust, oil, and debris can fall into the timing cover or cylinder head openings. Wipe down the engine bay and keep loose clothing and jewelry away from moving parts.

4. Review Service Manual Specifications

Locate your engine’s factory torque specs for camshaft bearing caps (typically 7–9 ft-lbs for B-series), timing belt tension, and valve cover bolts. Having these at hand prevents over-tightening and damage.

Step-by-Step Installation

Follow these steps in sequence. If you are experienced with Honda engines, you can move quickly through the disassembly, but double-check timing marks before removing the old camshaft.

1. Remove the Valve Cover and Spark Plugs

  • Remove the engine cover (if equipped) and any plastic engine bay trim.
  • Unbolt the valve cover bolts in a crisscross pattern to avoid warping. Set the cover aside.
  • Remove the spark plugs to make it easier to rotate the engine by hand later.
  • Clean the valve cover and cylinder head mating surfaces thoroughly. Replace the gasket and spark plug tube seals now.

2. Set the Engine to Top Dead Center (TDC) on Cylinder #1

Rotate the crankshaft clockwise using a 19mm socket on the crankshaft pulley bolt until the timing marks align:

  • Crankshaft pulley mark aligns with the 0° mark on the timing cover.
  • Camshaft gear marks are horizontal and pointing outward (the “UP” arrow at the top).
  • Check distributor rotor points to the #1 spark plug tower (if you have a factory distributor).

Verify TDC twice. Once the belt is removed, you cannot re-check easily, so accuracy here saves headaches later.

3. Remove the Timing Belt and Tensioner

  • Remove the upper and lower timing belt covers (usually 10mm bolts).
  • Loosen the timing belt tensioner bolt (12mm) and push the tensioner away from the belt to relieve tension. Tighten the tensioner bolt temporarily to hold it back.
  • Slide the timing belt off the camshaft gear and crankshaft pulley.
  • Remove the tensioner and idler pulley. Replace them with new ones from your timing belt kit.

Warning: Do not rotate the crankshaft or camshaft with the belt removed unless you are careful to avoid valve-to-piston contact. Keep the crankshaft at TDC and hold the cam gear steady.

4. Remove the Old Camshaft

  • Loosen the camshaft bearing cap bolts in sequence (from the ends toward the center) in several passes to prevent warping the caps.
  • Remove the bearing caps and keep them in order. Mark them with a marker or lay them out on a clean table in sequence.
  • Lift the old camshaft out of the cylinder head. Be careful not to scratch the bearing journals.
  • Clean the cam bearing saddles and journals with a lint-free cloth and brake cleaner.

5. Install the Skunk2 Stage 2 Camshaft

  • Apply a liberal amount of engine assembly lube or clean engine oil to the camshaft lobes and bearing journals.
  • Carefully place the Skunk2 camshaft into the bearing saddles. Make sure the cam gear keyway aligns with the correct orientation (the “UP” mark should face the top of the engine when at TDC).
  • Reinstall the bearing caps in their original positions and torque them in a crisscross pattern to the factory specification (usually 7–9 ft-lbs for B-series). Do not over-tighten.
  • Rotate the camshaft by hand using the cam gear bolt to verify smooth rotation. If there is binding, recheck cap alignment and torque.

6. Align and Install the New Timing Belt

  • Ensure the crankshaft is still at TDC. Install the new timing belt starting from the crankshaft pulley, then around the water pump, idler pulley, and finally the camshaft gear.
  • Install the new tensioner and idler pulley. Loosen the tensioner bolt to apply tension to the belt.
  • Rotate the engine two full revolutions clockwise with a socket on the crankshaft bolt. Recheck timing marks at TDC. They should align perfectly. If not, repeat the belt installation.
  • Adjust the timing belt tension according to the service manual (typically 1/2 to 3/4 inch deflection with moderate thumb pressure). Tighten the tensioner bolt to spec.

7. Check and Adjust Valve Lash (If Required)

Skunk2 Stage 2 camshafts often require a tighter valve lash than stock, typically 0.006–0.008 inches for intake and 0.008–0.010 inches for exhaust (check cam card). Use a feeler gauge between the cam lobe heel and rocker arm. Adjust by turning the adjustment screw and locking the nut. This step is critical for performance and longevity.

8. Reassemble the Engine

  • Install the new spark plugs (gap to spec).
  • Clean the valve cover and apply a thin bead of RTV at the half-moon seals and corners.
  • Install the new valve cover gasket and reinstall the valve cover. Torque bolts in a crisscross pattern to the service manual spec (typically 7–9 ft-lbs).
  • Reinstall the timing covers, engine trim, and connect the battery.

Post-Installation Checks

Before starting the engine, perform these checks to avoid damage:

  • Rotate the engine by hand two full turns. Listen for any mechanical interference. If it stops prematurely, you may have incorrect timing or valve contact.
  • Check for coolant or oil leaks around the timing cover, valve cover, and cam seals.
  • Verify all bolts are torqued to spec, especially the cam bearing caps and timing belt tensioner.
  • Start the engine. Listen for unusual ticking (excessive valve noise may indicate incorrect lash). Let it idle for a few minutes, then rev gently to check for smooth operation.
  • Check for DTCs (Diagnostic Trouble Codes). If your car has an OBD system, scan for codes that may indicate timing or sensor issues.

After a short test drive, recheck the valve lash and timing belt tension. New belts may stretch slightly and require re-tensioning after the first heat cycle.

Tuning Requirements for 20+ HP Gains

The Skunk2 Stage 2 camshaft has more duration and lift than stock, which shifts the power band higher. To realize the advertised 20+ HP increase, you must tune the engine management system. Without tuning, the engine may run lean at high RPM, hesitate, or even knock. Options include:

  • Chipped ECU with a basemap – Many tuners offer pre-made tune files for B-series with Skunk2 Stage 2 cams. You can burn these onto a Moates or similar chip.
  • Standalone ECU – Hondata S300, Haltech, or AEM EMS allows full control over fuel and ignition maps. This is the best route for maximum power and reliability.
  • Dyno tuning – After the initial start, schedule a dyno session to dial in the air-fuel ratio and ignition timing. Expect gains of 20–30 HP at the wheels with a proper tune.

Remember: a camshaft is just one part of the package. For best results, combine it with a good intake, header, and free-flowing exhaust. Skunk2 also recommends upgraded valve springs (like their 7500 RPM springs) to prevent valve float at high RPM.

Common Mistakes to Avoid

  • Not checking piston-to-valve clearance – Aggressive cams can cause interference if the engine has been milled or uses different pistons. Measure with clay or a dial indicator.
  • Ignoring timing marks – Misaligning the cam gear by even one tooth will cause poor performance and potentially bent valves.
  • Reusing old timing belt components – A new camshaft creates additional load. Always replace the belt, tensioner, and idler.
  • Over-tightening bearing caps – This can distort the cam bore and cause premature wear.
  • Skipping the valve lash adjustment – Lash that is too tight can cause burnt valves; too loose creates noisy valvetrain and power loss.

Conclusion

Installing a Skunk2 Stage 2 camshaft in your B-series engine is a rewarding project that can transform the car’s character and deliver a substantial horsepower increase. By following this detailed guide, taking your time with timing and lash adjustments, and investing in a proper ECU tune, you’ll unlock the full potential of your Honda’s VTEC head. For more technical data and product support, visit Skunk2’s official website or join the discussions on Honda-Tech forums where experienced builders share their setups and dyno results.

If you’re sourcing parts, reputable retailers like eBay Motors often have competitive pricing. Remember that performance gains come from proper installation and tuning—rushing the process can lead to expensive repairs. Happy building, and enjoy the extra 20+ horsepower on the road or track!