Introduction to the KA24DE Performance Camshaft Upgrade

The Nissan 240SX, powered by the legendary KA24DE engine, remains one of the most popular platforms for enthusiasts seeking reliable rear-wheel-drive performance. While the stock KA24DE delivers respectable torque for daily driving, its camshaft profile is designed primarily for fuel economy and emissions compliance. Swapping in a performance camshaft is one of the most effective single modifications you can make to unlock significant horsepower and torque gains across the entire RPM range.

A performance camshaft changes the valve timing, lift, and duration to improve the engine's ability to breathe at higher RPMs. This means more air and fuel enter the combustion chamber, and exhaust gases exit more efficiently, resulting in a measurable increase in power output. Whether you are building a drift car, a track-day weapon, or a spirited street machine, a KA24DE performance camshaft installation is a rewarding mechanical project that delivers tangible results.

This guide walks you through the entire process in a structured, three-step approach. You will learn how to prepare your workspace and gather the correct tools, safely remove the factory camshaft, and install your new performance camshaft with precision. Each section includes critical torque specifications, timing alignment details, and practical tips drawn from real-world installations. By the end of this article, you will have the confidence to perform this upgrade correctly and safely in your own garage.

Step 1: Preparation, Tools, and Workspace Setup

Proper preparation is the foundation of a successful camshaft installation. Rushing this phase leads to stripped bolts, damaged components, and unnecessary frustration. Before you touch a single wrench, take the time to gather every tool and part listed below, and arrange your workspace for efficiency.

Required Tools and Parts

  • KA24DE performance camshaft — Choose a reputable brand such as Kelford, Brian Crower, or JWT. Ensure the camshaft is specifically designed for the KA24DE (dual overhead cam) engine.
  • Complete socket set — Metric sizes from 8mm to 19mm, including a 10mm, 12mm, 14mm, and 17mm socket. A deep-well 10mm socket is essential for valve cover bolts.
  • Torque wrench — A 3/8-inch drive torque wrench capable of measuring in Newton-meters (Nm) and foot-pounds (ft-lbs). Accuracy is critical for camshaft cap bolts.
  • Camshaft installation tool (alignment tool) — Some performance camshafts require a specific alignment tool to match the cam gear bolt pattern. Confirm compatibility with your camshaft manufacturer.
  • Timing chain tensioner tool — A simple pin or clip to hold the hydraulic tensioner compressed during removal and installation.
  • Engine oil and assembly lube — Use a high-zinc break-in oil or dedicated assembly lube on cam lobes and journals. Do not use standard multigrade oil for initial startup.
  • Gasket sealant and new gaskets — Nissan OEM valve cover gasket and camshaft seal (front and rear). RTV silicone gasket maker for the timing cover.
  • Clean rags and degreaser — Brake cleaner or isopropyl alcohol for cleaning sealing surfaces.
  • Shop manual or timing reference — A printed copy of the factory service manual (FSM) timing marks diagram. Do not rely on memory.

Workspace and Safety Preparations

Park the vehicle on a level surface and disconnect the negative battery terminal. Allow the engine to cool completely if it has been running — the coolant temperature should be below 40°C (100°F) to avoid burns from hot components. Remove the engine cover and air intake ducting to improve access to the valve cover. If possible, use a fender cover to protect the paint and a drip pan to catch any coolant or oil spillage.

Take a moment to photograph the engine bay layout and the orientation of any wiring harness brackets. These photos will serve as a reference during reassembly. Label any vacuum lines or connectors you disconnect with masking tape and a marker. This small investment of time prevents guesswork later.

Step 2: Removing the Factory Camshaft

Removing the KA24DE camshaft requires removing the valve cover, timing chain cover, and timing chain tensioner. The factory camshaft is retained by cam caps that must be loosened in a specific sequence to prevent warping. Follow these steps carefully.

Draining Fluids and Disconnecting Components

Drain the engine oil and remove the oil filter. This is a good opportunity to replace both with fresh oil and a new filter during reassembly. Remove the spark plug wires or coil packs to keep them out of the way. If your 240SX has a distribution system, mark the distributor position before removing it — this preserves your base ignition timing.

Removing the Valve Cover

Remove the valve cover bolts using a 10mm socket. These bolts are known to strip if overtightened, so check each one carefully. Gently pry the valve cover loose with a plastic trim tool — do not use a metal screwdriver against the aluminum cylinder head surface. Clean the mating surfaces on both the valve cover and the cylinder head with brake cleaner and a lint-free rag.

Accessing the Timing Chain and Camshaft

Remove the upper timing chain cover. This cover is held by 10mm and 12mm bolts. Some bolts are hidden behind the power steering pump bracket or alternator bracket. A flexible extension socket may be necessary for the lower bolts. Once the cover is off, rotate the crankshaft clockwise using a 19mm socket on the crank pulley bolt until the timing marks align. The factory service manual details the exact alignment: the notch on the crankshaft sprocket aligns with the mark on the oil pump housing, and the camshaft sprocket dots align with the chain links or cover marks.

Removing the Timing Chain Tensioner

The hydraulic timing chain tensioner must be removed before the camshaft sprockets. Locate the tensioner on the driver's side of the engine, near the timing cover. Remove the two 10mm bolts that secure it, and compress the tensioner plunger slowly. Lock the compressed tensioner with a small Allen key or a paper clip through the locking hole. Set the tensioner aside in a clean location.

Removing the Camshaft

Remove the camshaft sprocket bolts. The intake cam sprocket bolt is typically 24mm, and the exhaust cam sprocket bolt is 22mm. Use a breaker bar and a camshaft holding tool to prevent the cam from rotating. If you do not have a holding tool, you can use a large adjustable wrench on the hex section of the camshaft (between lobes) as a backup. Do not rely on the timing chain to hold the sprocket — it can cause the chain to skip teeth.

With the sprockets removed, remove the camshaft cap bolts in a reverse spiral pattern (from the outside in). There are ten cam caps, each with two 10mm bolts. Loosen each bolt a quarter turn at a time until all are free. Lift the cam caps straight up and store them in order — they are precision-machined to their specific positions and must not be swapped.

Lift the factory camshaft straight out of the cylinder head. Clean the camshaft journals and the bearing surfaces in the cylinder head with a clean rag and brake cleaner. Inspect the journals for scoring or galling. Any damage here requires professional machining or replacement of the cylinder head.

Step 3: Installing the Performance Camshaft

Installation of the new performance camshaft demands patience and precision. The performance camshaft has more aggressive lobe profiles, which means clearances between the cam lobes and valve buckets must be verified. Do not skip this step.

Preparation and Lubrication

Apply a generous layer of assembly lube to each camshaft journal and lobe. Use a high-zinc formula specifically designed for flat-tappet camshafts. Even if your KA24DE uses roller followers, the cam lobes still require a high-pressure lubricant for the first few minutes of operation. Rotate the camshaft by hand to spread the lube evenly across all surfaces.

Installing the Camshaft and Timing

Lower the new performance camshaft into the cylinder head. Make sure the alignment dowel or keyway on the camshaft matches the sprocket position. Place the cam caps back onto the cylinder head in their original order and orientation. The manufacturer typically stamps an arrow or number on each cap to indicate its position. Hand-thread all cam cap bolts until snug, then torque them in a spiral pattern from the center outward to 12 Nm (9 ft-lbs) in three stages. Do not overtighten — the aluminum threads in the cylinder head strip easily.

Reinstall the timing chain sprockets onto the camshafts. Ensure the timing chain alignment marks match the factory specification. Rotate the engine two full turns by hand (using the 19mm crank socket) and recheck the alignment. If the marks do not line up, repeat the installation procedure. Incorrect timing will cause poor performance and possible engine damage.

Final Assembly and Torque Specifications

Install a new front camshaft seal and rear camshaft plug. Coat the outer edge of the seal with a thin layer of engine oil before pressing it into place. Reinstall the timing chain tensioner with a new gasket. Remove the locking pin from the tensioner after it is bolted in place. The tensioner plunger will extend and apply pressure to the chain guide automatically.

Clean the valve cover and install a new gasket. Apply a small bead of RTV silicone to the corners of the timing cover where the gasket meets the cylinder head. Torque the valve cover bolts to 4 Nm (3 ft-lbs) in a cross pattern. Overtightening here can crack the valve cover. Reinstall all previously removed components: distributor or coil packs, spark plugs, air intake ducting, and the negative battery terminal.

Post-Installation: Engine Break-In and Tuning

Installing a performance camshaft is only half the equation. The engine must be properly broken in, and the ECU may require recalibration to take full advantage of the new cam profile. This section covers the critical steps after the mechanical installation is complete.

Engine Break-In Procedure

Fill the engine with a high-zinc break-in oil and a new oil filter. Do not use synthetic oil for the first 500 miles — synthetic oils do not allow the camshaft lobes and followers to seat properly. Start the engine and let it idle at approximately 2000 RPM for 20 minutes. This is a standardized camshaft break-in procedure that allows the cam lobes to mate with the valve train components. Monitor the engine for any unusual noises, leaks, or smoke. If you hear a tapping sound from the top end, the valve lash may need adjustment — some performance camshafts require solid lifters or shim adjustment.

After the initial 20-minute idle, perform a series of gentle acceleration runs from 2000 RPM to 4000 RPM under light load. Do not exceed 4000 RPM or apply full throttle during the first 100 miles. Change the oil and filter after 100 miles and again after 500 miles. Inspect the oil for metallic particles — a small amount is normal during break-in, but excessive glitter indicates a problem.

ECU Tuning Considerations

A performance camshaft shifts the engine's volumetric efficiency curve, which means the factory ECU's fuel and ignition maps are no longer optimal. At a minimum, consider a reflash or a piggyback tuning solution such as Nistune or a standalone ECU like MegaSquirt or Haltech. Tuning allows you to adjust the air-fuel ratio, ignition timing, and idle speed control to match the new cam profile. Without tuning, you may experience a rough idle, flat spots in the power band, or even knocking under load.

Standard tuning upgrades to accompany a performance camshaft include larger fuel injectors (370cc to 550cc depending on the cam), a high-flow exhaust system, and a cold air intake. These modifications ensure the engine can breathe freely and deliver the power the camshaft is capable of producing. A dyno tune is the definitive way to verify gains and ensure the engine runs safely.

Performance Expectations and Practical Considerations

Depending on the camshaft profile you choose, expect a gain of 20 to 40 horsepower at the wheels for a mild "Stage 1" camshaft, and up to 60 horsepower for a "Stage 2" or "Stage 3" profile. These gains come with a trade-off: more aggressive camshafts reduce low-RPM torque and may require higher idle speeds (900-1100 RPM) to remain stable. The engine may also have a lumpy idle characteristic that some drivers find charming and others find annoying for daily driving.

Real-world driving with a performance camshaft requires a higher RPM range for power delivery. You will feel the engine come alive above 3500 RPM and pull strong to 6500 RPM or more. This makes the car noticeably faster in track or autocross situations, but the engine may feel less responsive in stop-and-go traffic. Plan your driving style accordingly, and consider upgrading your clutch if you are also increasing power with supporting modifications.

Final Thoughts

Installing a KA24DE performance camshaft is a mechanical milestone for any Nissan 240SX enthusiast. The process is well within the capabilities of a home mechanic with moderate experience, provided you respect the torque specifications, timing marks, and break-in procedures outlined in this guide. The result is a more responsive, more powerful engine that rewards every shift with a satisfying surge of acceleration.

For further reference, consult the official Nissan factory service manual for the 240SX for detailed torque values and exploded diagrams. Research camshaft profiles from reputable manufacturers such as Kelford Cams or Brian Crower to choose a profile that matches your performance goals. Finally, join the Zilvia.net forum community to connect with other builders who have completed this exact installation — their real-world experiences are invaluable.