Understanding the KA24DE Stage 2 Camshaft Upgrade

Installing a Stage 2 camshaft in your KA24DE engine is one of the most effective bolt-on modifications for unlocking real-world horsepower and driveability. Unlike milder Stage 1 cams that focus on low-end torque, a well-designed Stage 2 camshaft provides a balanced gain across the mid-to-upper rpm range, adding approximately 10–15 horsepower at the wheels while noticeably sharpening throttle response. This upgrade is particularly popular among enthusiasts running naturally aspirated setups with supporting modifications such as headers, intake, and tuned ECU.

The KA24DE, found in the 240SX (S13 and S14) as well as the Nissan Altima and some trucks, responds exceptionally well to increased valve lift and duration. A Stage 2 camshaft typically features 256–264 degrees of duration and lift around 0.480–0.500 inches. These numbers deliver stronger top-end pull without sacrificing too much low-end drivability, making this cam an ideal choice for daily drivers that see track or autocross time. Before you start turning wrenches, it's critical to understand the full scope of the installation process and the additional components you may need to support the new cam profile.

This guide will walk you through every step of the KA24DE Stage 2 camshaft installation – from tools and preparation to removal, installation, reassembly, and testing. Follow these instructions carefully to ensure a leak-free, reliable installation that performs exactly as intended. For additional background on KA24DE tuning and camshaft selection, refer to Zilvia.net's KA-T forum and 240SX.org's technical archives.

Tools, Materials, and Parts Checklist

Proper preparation prevents poor performance. Gather the following items before you begin. Having everything on hand will minimize downtime and prevent frustrating trips to the parts store in the middle of the job.

Required Tools

  • Metric socket set (8mm, 10mm, 12mm, 14mm, 17mm) with extensions
  • Torque wrench (capable of 10–80 N·m / 7–60 lb-ft)
  • Camshaft gear holding tool or chain tensioner tool
  • Gasket scraper (plastic or brass to avoid gouging aluminum)
  • Clean shop rags and brake cleaner
  • Safety goggles and nitrile gloves
  • Drain pan (to catch engine oil)
  • Feeler gauge (to check valve clearance if applicable)
  • Timing chain wedge or chain holder

Parts and Consumables

  • KA24DE Stage 2 camshaft (new or reground – Brian Atlas, Cox Racing, or IAP (Imported Auto Parts) are reputable suppliers)
  • New camshaft oil seal (front and rear)
  • Valve cover gasket set (cam cover gasket, spark plug tube seals, half-moon seals)
  • Engine oil (5W-30 or 10W-30, high-zinc break-in oil recommended)
  • New oil filter
  • Thread lock compound (medium-strength, for cam sprocket bolts)
  • Permatex Ultra Black or Right Stuff gasket maker (for valve cover corners)
  • Assembly lube (moly-based for cam lobes and journals)

Preparation: Safety and Engine Readiness

Workspace and Safety

Work on a level surface with adequate lighting. Disconnect the battery negative terminal to prevent accidental cranking. Allow the engine to cool completely – removing the valve cover on a hot engine risks warping the cover and burns. Keep a fire extinguisher nearby, especially if you'll be using flammable cleaners.

Draining Oil and Removing Accessories

Drain the engine oil into a clean drain pan. It is easier to remove the valve cover and camshaft without oil puddling; fresh oil will be added later. Remove any components that block access to the camshaft cover: the intake air duct, intake plenum bracket, and any wiring harness clips secured to the valve cover. On S14 KA24DEs, you may need to unbolt the engine wiring harness from the intake manifold side to flip it out of the way.

Timing Considerations

Installing a Stage 2 camshaft requires attention to timing chain position. The KA24DE uses a single-row timing chain. You will need to secure the chain so it does not fall off the lower sprocket. Use a timing chain wedge (or a zip tie through the chain links) to hold tension. If you are unsure of your engine’s timing chain condition, now is a good time to inspect and replace the chain tensioner and guides – consult Nicoclub.com's KA24DE service manual for torque specs and chain inspection procedures.

Removing the Stock Camshaft

Step 1: Remove the Valve Cover

Unbolt the camshaft cover (valve cover) using a 10mm socket. There are 14 bolts on the KA24DE valve cover – do not overtighten during reassembly. Carefully lift the cover. If it sticks, gently tap it with a rubber mallet. Set it on a clean surface. Remove the old gasket and clean the cover thoroughly. Use a gasket scraper to remove any old sealant from the cover and the cylinder head surface.

Step 2: Remove the Camshaft Sprocket

Rotate the engine to top dead center (TDC) on cylinder No. 1 (aligned with the 0 degree mark on the crank pulley and the timing mark on the cam sprocket pointing up). Mark the chain-to-sprocket relationship with a paint marker. Use a cam gear holding tool to prevent the cam from turning. Loosen the cam sprocket bolt (17mm). Remove the bolt and slide the sprocket off the cam. Use a piece of wire or zip tie to keep the chain engaged lightly with the lower sprocket.

Step 3: Unbolt and Remove the Camshaft

The camshaft is held by bearing caps (journals). For the KA24DE, there are two pairs: the intake cam and the exhaust cam. The camshaft you are replacing (the exhaust cam in most single-cam KA24DE? Actually note: the KA24DE is a dual overhead cam – intake cam and exhaust cam. A Stage 2 upgrade may involve replacing one or both. For simplicity, this guide assumes you are replacing both, but many aftermarket Stage 2 camshafts are sold as a set with separate intake and exhaust profiles. Check your camshaft supplier's specifications.

Loosen the bearing cap bolts in a crisscross pattern, gradually, to prevent bending the cam. Remove the caps and keep them in order. Lift the camshaft(s) out. Place them in a clean bag or wrap in rags to avoid contamination.

Installing the Stage 2 Camshaft

Lubrication and Alignment

Liberally apply assembly lube to the camshaft journals and lobes. Install the new camshaft(s) into the cylinder head. Ensure the cam sits flush. Install the bearing caps in the correct order and torque them to 12–14 N·m (9–10 lb-ft) in two stages. Do not overtighten – KA24DE bearing caps are aluminum and strip easily.

Timing Chain and Sprocket Installation

Slide the cam sprocket onto the new camshaft, aligning the keyway. Do not reuse the old sprocket bolts – purchase new ones (OEM or ARP). Apply thread locker to the bolt and torque to 37 N·m (27 lb-ft). Verify the timing chain marks have not shifted. Rotate the crank by hand two full revolutions and recheck the cam timing marks. If marks are off, the chain may have skipped – you must restart the alignment process.

Valve Clearance Check (If Required)

Some Stage 2 camshafts require adjusting valve lash. The KA24DE uses a shim-over-bucket design. After installation, use a feeler gauge to check clearance between the cam lobe and bucket at TDC. Typical cold intake clearance is 0.20–0.25 mm, exhaust 0.25–0.30 mm. If adjustments are needed, you will need a shim kit and a bucket depressor tool. Many aftermarket camshafts come with a spec sheet – follow it precisely.

Reassembly and Sealing

Camshaft Cover Installation

Apply a thin bead of RTV silicone at the corners where the cam cover meets the front timing cover and the half-moon seals. Install the new valve cover gasket into the cover groove. Press the spark plug tube seals in. Carefully lower the valve cover onto the cylinder head. Install the 14 bolts and tighten in a spiral pattern to 4 N·m (3 lb-ft) – very light. Overtightening will crack the cover.

Reconnecting Accessories and Refilling Oil

Reinstall the intake air duct, wiring harness, and any brackets. Refill the engine with fresh oil (4.2 quarts with filter change). Use a high-zinc break-in oil if the camshaft is new; zinc prevents lobe wear during the initial 20 minutes of operation. Reconnect the battery.

First Start and Break-In Procedure

Start the engine and let it idle at around 2000 rpm for 20 minutes. Do not let it idle below 1500 rpm – the cam lobes need oil splash during break-in. Watch for oil leaks around the cam cover and chain tensioner. After 20 minutes, change the oil and filter again. This removes assembly lube and wear particles.

During the first drive, avoid sustained high rpm (over 4500) for the first 100 miles. Vary engine speed to allow the rings to seat if you also changed pistons. The improved throttle response will be immediately noticeable: a sharper tip-in and stronger mid-range pull.

Tuning for Maximum Benefit

A Stage 2 camshaft alters the volumetric efficiency curve, so a factory ECU will not be optimal. To fully realize the 15+ horsepower gain, you should upgrade the engine management. Options include:

  • Nistune – allows real-time tuning on stock ECU
  • Megasquirt or Haltech standalone systems – offer full control
  • JWT ECU tune – mail-order recalibration for specific cam profiles

If you skip tuning, you may experience a lean condition at high rpm and reduced power. Add an aftermarket fuel pump and adjustable fuel pressure regulator if required. For a complete guide to KA24DE tuning, see KA-T.org’s tuning resources.

Performance Expectations and Supporting Modifications

On a stock long block, a Stage 2 cam alone will deliver about 10–15 whp with a good tune. To maximize your investment, pair the cam with:

  • Cold air intake or short ram intake
  • 4-1 or 4-2-1 header (1 5/8 inch primary tubes)
  • 2.5-inch mandrel-bent exhaust system
  • Underdrive pulleys (optional)
  • Upgraded valve springs (single or dual) – recommended for Stage 2 to prevent valve float above 6800 rpm

Installing new valve springs while the cams are out is highly recommended. The stock springs are designed for stock lift and duration; stiffer aftermarket springs ensure stable valve control at higher rpm. Brands like Supertech and Brian Crower offer direct-replacement springs for the KA24DE.

Troubleshooting Common Issues

Oil leaks at the cam cover: Usually caused by worn spark plug tube seals or over-tightened cover bolts. Replace seals and use a torque wrench set to 4 N·m.

Rough idle or surging: May indicate cam timing off by one tooth. Re-check timing marks. Also ensure the MAF sensor is clean and there are no vacuum leaks.

No power gain: Verify that the camshaft is actually a Stage 2 profile – some generic "stage 2" cams have minimal changes. Check specs against your supplier’s documentation. Also confirm that your ECU tune supports the cam's advanced duration.

Ticking noise from the head: Could be excessive valve lash (too loose) or insufficient oil supply. Check clearance and oil level. If noise persists, inspect the cam lobes and followers for damage.

Conclusion

Installing a KA24DE Stage 2 camshaft is a rewarding project that transforms the character of your 240SX or Nissan KA-powered vehicle. With careful attention to timing, torque specifications, and break-in procedures, you can safely and confidently add 15 horsepower and a crisp throttle response that makes every drive more engaging. Take your time, use quality parts, and don’t skip the tuning step – your engine will thank you with years of reliable performance.

Now that you have the complete blueprint, gather your tools and fire up the engine lift. Your KA24DE deserves that next level of performance.