Complete Guide to Installing a Toda Camshaft on Your Rsx Type S for 15 Hp More

Introduction to the Toda Camshaft Upgrade

Installing a Toda camshaft in your RSX Type S is one of the most effective bolt-on modifications to unlock additional horsepower from the K20A2 or K20Z1 engine. The Toda Racing camshaft is engineered with aggressive lobe profiles that increase valve lift and duration, improving volumetric efficiency across the rev range. With proper installation, you can expect a gain of 10–15 wheel horsepower, accompanied by a more responsive throttle and a distinctive engine note. This guide provides a comprehensive, step-by-step process to ensure a successful installation while covering critical details that many abbreviated tutorials overlook.

Before starting, verify that your engine is in good mechanical condition. A compression test and leak-down test are recommended to confirm that the valvetrain and piston rings are healthy. The Toda camshaft works best with a proper ECU tune; factor that into your budget. This guide assumes you have basic mechanical experience and access to quality tools.

What the Toda Camshaft Offers

Toda Racing’s camshafts for the K-series engine are designed for aggressive daily driving and track use. The specific cam for the RSX Type S (part number 11004-0006 for the exhaust or a paired intake/exhaust set) offers:

• Increased lift and duration: More fuel and air enter the cylinder, raising peak power without sacrificing low-end drivability entirely.
• Optimized lobe separation: Improves scavenging and reduces reversion, especially at high RPM.
• Drop-in design: No modifications to the cylinder head are required; the cam journals and bearing journals match factory specifications.
• Proven gains: When paired with a good header, intake, and tune, the 15 hp increase is achievable at the wheels.

For detailed specifications and compatibility, refer to the official Toda Racing website.

Tools and Materials Required

Gather all items before starting to avoid interruptions:

Category	Items
Sockets & Ratchets	10mm, 12mm, 14mm, 17mm sockets; extensions; swivel joint; torque wrench (3/8" and 1/2")
Hand Tools	Flathead and Phillips screwdrivers, hex keys (metric), camshaft holding tool (Toda or equivalent), harmonic balancer holder, pry bars
Special Tools	K-series camshaft gear removal/installation tool, valve clearance gauge (feeler gauge), cam cap socket (8mm hex bit)
Consumables	New camshaft seals (front and rear), valve cover gasket, spark plug tube seals, RTV silicone (high-temp), engine oil (5W-30 or recommended), coolant (Honda Type 2), thread locker (medium-strength)
Other	Shop rags, drain pan, fender covers, safety glasses, torque specs sheet (from Toda or Honda service manual)

Tip: A factory service manual for the 2002–2006 Honda RSX is invaluable. You can often find a digital copy on sites like KSeriesParts.

Preparation: Engine and Work Area

Proper preparation prevents mistakes and damage. Follow these steps:

1. Park on a level surface and allow the engine to cool completely (at least 2 hours).
2. Disconnect the battery negative terminal to prevent accidental cranking or short circuits.
3. Drain the engine oil and coolant. Removing the valve cover is easier when oil isn’t pooling around the cam caps. Drain the coolant from the radiator petcock to avoid a mess when removing the thermostat housing or intake manifold.
4. Remove the air intake assembly and intake manifold (optional but recommended) to access the valve cover bolts on the driver side. You can skip this if you’re careful, but removing the manifold gives better clearance.
5. Detach all wiring harness brackets, spark plug wires, and fuel rail covers. Label connectors if needed.
6. Mark the camshaft timing position with a paint marker or scriber before loosening anything. The factory timing marks are on the cam gears and the cylinder head. Photograph these for reference.

Clean the engine bay around the valve cover to prevent dirt from falling into the cam journal area.

Removing the Stock Camshaft

This is the most critical section; torque sequences and handling are vital.

Remove the Valve Cover

1. Unbolt the 12mm bolts holding the valve cover in a cross-pattern sequence. There are 10 bolts (depending on year).
2. Gently pry the cover loose using a flathead screwdriver at the corners. Do not warp the cover.
3. Lift the cover off and inspect the old gasket. Replace it with a new one during reassembly.

Remove the Camshaft Timing Chain or Belt

The K20A2 uses a timing chain. You do not need to remove the entire chain – only loosen tension so the cam gears can be detached.

1. Rotate the crankshaft to TDC (top dead center) for cylinder #1 using a breaker bar on the crank pulley. The cam gears should have the “UP” mark aligned.
2. Remove the upper timing chain cover (several 10mm bolts).
3. Use a camshaft holding tool to keep the cams from rotating. If unavailable, use a large adjustable wrench on the hex on the camshaft (between lobes).
4. Remove the cam gear bolts (external cross-recess or 12-point; use a T45 Torx or 12mm Allen depending on aftermarket gear).
5. Slide the cam gear off the camshaft.
6. Remove the VTC actuator (if equipped) or the sprocket assembly. Note orientation.
7. Compress the timing chain tensioner using a suitable tool to release tension. On K20A2, you can use a thin flathead to push the tensioner shoe in. Alternatively, remove the tensioner assembly (two bolts).
8. Remove the chain from the cam sprocket. Keep the chain from falling into the oil pan.

Important: Do not let the crankshaft rotate after removing the chain. If it moves, you will need to re-time the engine, which is possible but adds complexity.

Remove the Camshaft Caps and Cam

1. Label each cam cap with its position (intake/exhaust and number) using a marker or tape. The caps are not interchangeable; mixing them up will cause galling.
2. Loosen the cam cap bolts in reverse tightening order – start from the ends and work inward in 1/4 turn steps to avoid bending the camshaft.
3. Lift the cam caps off and set them aside in order.
4. Remove the camshaft from the head by sliding it out toward the transmission side (exhaust cam) or front (intake). Be careful not to scratch the bearing journals or the head surface.

Preparing for the Toda Camshaft Installation

Before installing the new cam, perform the following checks:

• Clean the bearing journals in the head and the cam caps using a lint-free cloth and brake cleaner.
• Apply a thin coat of assembly lube to each journal and lobe. Toda cams are typically hardened, but initial lubrication is essential.
• Check valve clearance while the old cam is out. Measure the gaps between the valve shims and tappets. The Toda camshaft may require different clearances than stock – refer to the cam card included with your cam. Typical specs: intake 0.06–0.08 mm, exhaust 0.08–0.10 mm for a performance cam. Write down the current gaps and determine if shim replacement is needed.
• Replace camshaft seals – always use new front and rear seals. Lubricate the inner lip with engine oil before installation.

Installing the Toda Camshaft

Positioning the New Cam

1. Slide the Toda camshaft into the head in the same orientation as the stock unit. The exhaust cam typically has a gear with a different offset; ensure the keyway aligns with the cam gear.
2. Rotate the cam slightly to seat it into the rear journal seal.
3. Install the cam caps in their correct positions and in the correct order. Hand-tighten the bolts.

Torque Sequence for Cam Caps:

• Tighten all bolts in three steps: 5 ft-lb, 10 ft-lb, then final 14–16 ft-lb (20–22 Nm).
• Always torque from the center outward in a crisscross pattern.
• Use a torque wrench; over-torquing can warp the caps or damage the cam.

Reinstall Timing Components

1. Reattach the timing chain to the cam gear(s). Ensure the timing marks align: the crankshaft sprocket mark at TDC (usually a notch at 12 o’clock), the cam gear marks (e.g., arrow pointing up, or colored link aligned with timing mark).
2. Install the tensioner and set the tension. For K20A2, after installing the tensioner, rotate the engine by hand two full revolutions and re-check timing marks.
3. Tighten cam gear bolts to factory torque: 61 ft-lb (83 Nm) for the intake cam gear, and 9–12 ft-lb for the VTC actuator bolts if applicable. Use thread locker on these bolts.
4. Replace the upper timing chain cover with a new gasket.

Valve Adjustment: A Must After Cam Swap

After the camshaft is installed and timed, you must adjust the valve clearances. The Toda camshaft’s lobe profiles are different, and even if you measured before, the final clearance may change after torquing the caps.

1. Remove the spark plugs to reduce engine rotation resistance.
2. Rotate the crankshaft to TDC for cylinder #1 (both cam lobes point upward at 10 and 2 o’clock).
3. Use a feeler gauge to measure the gap between the cam lobe and the valve tappet for cylinder #1 intake and exhaust. Compare to Toda’s spec.
4. Record all gaps for all cylinders in order: 1, 2, 3, 4.
5. If a gap is outside spec, replace the shim under the tappet. K-series engines use 16mm shims. You can buy individual shims from Honda (available in 0.025 mm increments).
6. Re-measure after shim replacement. Repeat until all clearances are within spec.

Note: Some tuners recommend setting clearances slightly wider on the exhaust side to compensate for heat expansion, but stick to Toda’s recommendations for initial run-in.

Reassembly of the Engine

1. Valve cover installation: Clean the mating surfaces thoroughly. Apply a small bead of high-temp RTV silicone at the timing chain cover joints (per Honda service manual). Install the new valve cover gasket into the cover groove. Place the cover on the head and torque the bolts in sequence: 7.2 ft-lb (9.8 Nm) in a cross-pattern.
2. Install the intake manifold and throttle body (if removed) with new gaskets. Torque evenly.
3. Reconnect all wiring, sensors, vacuum lines, and fuel rail. Double-check connectors for security.
4. Install new spark plugs if due; gap them to factory spec for modified engines (a slightly tighter gap may help if you are running higher boost or larger cam).
5. Fill with fresh engine oil – use a quality 5W-30 or 10W-40 synthetic. Also refill with coolant and bleed the system.
6. Reconnect the battery.

First Start and Break-In Procedure

The new camshaft requires a break-in period to ensure proper lobe and lifter wear. Follow these steps:

1. Before starting, prime the oil system – disable the ignition and crank the engine for about 10 seconds in 5-second bursts. This builds oil pressure to the cam journals.
2. Start the engine and immediately listen for any unusual ticking (valve noise is normal but should be uniform). Check for oil leaks around the cam plugs and valve cover.
3. Idle the engine at around 2000–2500 RPM for the first 15 minutes – do not let it idle too low as rich fuel mixtures can wash down cylinder walls. Monitor coolant temperature.
4. After 15 minutes, shut off the engine and let it cool for an hour.
5. Re-torque the cam cap bolts once hot (engine off) – only after the first heat cycle. Check valve clearances again after break-in; many tuners recommend a re-adjustment after 500 miles.
6. Drive gently for the first 100 miles, varying RPM but avoiding full throttle and high RPMs. Change oil and filter after 500 miles to remove any metal particles from break-in.

Tuning and Performance Expectations

Installing a Toda camshaft without an ECU tune is not recommended. The stock Honda ECU will adjust some parameters via closed-loop, but at wide-open throttle the increased airflow will cause lean conditions. You will need:

• Hondata FlashPro or K-Pro for the RSX – allows re-tuning of fuel, ignition timing, and VTC mapping.
• A reputable tuner with experience on K-series engines.
• Expect 10–15 whp gains on a dyno when combined with a cold air intake, header, and exhaust. Without supporting mods, the cam alone may yield 8–10 whp.

A proper tune will also recalibrate the throttle response and ensure emissions compliance. Many tuners offer base maps for Toda cams. Check resources like Hondata for tuning solutions.

Common Pitfalls to Avoid

• Mixing cam caps – leads to journal scoring and seized cams. Label meticulously.
• Incorrect timing – a single tooth off can cause poor performance or piston-to-valve contact. Double-check marks before starting.
• Skipping valve adjustment – leads to noisy valvetrain, power loss, or burnt valves.
• Using incorrect oil during break-in – avoid synthetic oils for the first 500 miles; use a conventional 10W-30 that contains zinc additives (ZDDP) to protect flat tappets. Toda camshafts are billet steel, but ZDDP is still beneficial.
• Forgetting to prime the oil pump – can cause instantaneous cam journal damage.

Conclusion

Installing a Toda camshaft on your RSX Type S is a rewarding DIY project that delivers genuine horsepower gains if executed with precision. By following this comprehensive guide – from careful removal to proper break-in – you can avoid costly mistakes and enjoy the improved throttle response, aggressive idle, and extra power that the Toda camshaft provides. Remember that a quality tune and supporting modifications are essential to realize the full 15 hp potential. For further reading, consult the K20A.org forums for real-world experiences and additional tuning tips. Happy wrenching.