How to Install an Aftermarket Camshaft on an 8th Gen Honda Civic R18
Tackling a camshaft swap on Honda's R18 engine delivers noticeable power across the mid-to-high RPM range, provided you maintain strict timing alignment and accurate valve lash. With basic hand tools and patience, this installation can be completed in your home garage while saving significant labor costs.
The Short Answer (TL;DR)
Installing an aftermarket camshaft on an 8th Generation Honda Civic (2006–2011 R18 1.8L) takes approximately 4 to 6 hours. The process requires setting the engine to Top Dead Center (TDC), securing the timing chain to the cam gear, removing the rocker arm assembly, installing the new cam with assembly lube, and executing a complete valve lash adjustment before reassembly.
Tools Needed
- 1/4-inch and 3/8-inch drive ratchets with extensions
- 10mm, 12mm, 14mm, and 19mm sockets
- Inch-pound and foot-pound torque wrenches
- Angled feeler gauges (for valve lash adjustment)
- Flathead and Phillips screwdrivers
- Heavy-duty zip ties or safety wire (to secure timing chain to the cam sprocket)
- High-pressure camshaft assembly lube
- Fresh engine oil
- New valve cover gasket set and tube of Hondabond/high-temp RTV
The Step-by-Step Process
Step 1: Preparation and Disassembly
Disconnect the negative battery terminal. Remove the plastic engine cover, unbolt the coil packs, and disconnect all wiring harnesses running across the top of the cylinder head. Unhook the PCV and breather hoses, then remove the valve cover perimeter bolts to lift the valve cover off the head.
Step 2: Set Cylinder 1 to Top Dead Center (TDC)
Using a 19mm socket on the crankshaft pulley bolt, rotate the engine clockwise until the timing marks on the camshaft sprocket align flush with the top edge of the cylinder head surface and the 'UP' arrow points directly upward. This confirms cylinder 1 is at Top Dead Center on the compression stroke.
Step 3: Secure the Timing Chain to the Cam Sprocket
To avoid removing the front timing chain cover, secure the timing chain firmly to the cam gear using two heavy-duty zip ties threaded through the sprocket windows. Relieve tension from the chain tensioner via the maintenance access port on the timing cover, insert a retention pin, and carefully unbolt the cam gear from the camshaft snout while keeping tension on the chain.
Step 4: Remove the Rocker Arm Assembly
Loosen the camshaft holder and rocker assembly bolts in reverse order of the tightening sequence (working from the outside inward) in two to three passes to prevent warping the camshaft or binding the rocker bridges. Carefully lift the rocker arm assembly off the cylinder head as a single unit and store it on a clean surface.
Step 5: Camshaft Swap and Lubrication
Lift the factory camshaft straight out of the cylinder head journals. Inspect the head journals for scoring. Coat all lobes, journals, and distributor drive slots on the new aftermarket camshaft thoroughly with high-pressure assembly lube. Lower the new camshaft into position, ensuring it sits squarely in the journals.
Step 6: Reinstall Rocker Assembly and Torque to Spec
Reinstall the rocker assembly over the new camshaft. Apply fresh engine oil to the threads and seating surfaces of the camshaft holder bolts. Torque the bolts in the factory cross-pattern sequence starting from the center and working outward. Tighten in steps to the final factory specification (16 lb-ft for 8mm bolts, 8.7 lb-ft for 6mm bolts).
Step 7: Perform a Valve Lash Adjustment
Rotate the engine through each cylinder's TDC position to adjust valve clearances. Using angled feeler gauges, adjust the intake valves to 0.18–0.22 mm (0.007–0.009 in) and exhaust valves to 0.23–0.27 mm (0.009–0.011 in). Tighten the locknuts while holding the adjustment screw stationary with a flathead screwdriver.
Step 8: Reassembly and First Start
Reinstall the cam gear onto the new camshaft, verifying timing marks match TDC. Re-engage the timing chain tensioner and snip the zip ties. Apply a small dab of Hondabond at the cylinder head mating corners, install the valve cover with a fresh gasket, and reinstall coils, plugs, and harness brackets. Change the engine oil and filter prior to starting the engine, and follow the manufacturer's break-in procedure.
Why You Should Upgrade While You're In There
Since the cylinder head is exposed and disassembled, this is the most cost-effective time to install upgraded valve springs and titanium retainers if running high-lift profiles, as well as a fresh timing chain tensioner to prevent future slack issues.
Recommended Upgrade: Performance ECU Tuner / Engine Management Programmer to recalibrate air-fuel ratios, optimize VTEC transition points, and maximize high-RPM efficiency with the new camshaft profile.
Frequently Asked Questions
Do I need an ECU tune after installing an aftermarket R18 camshaft?
Yes. The altered lobe duration and lift change cylinder volumetric efficiency across the rev range. Running the factory calibration can cause lean air-fuel conditions and prevent the engine from extracting the performance gains designed into the camshaft profile.
Can I complete this camshaft swap without removing the front timing cover?
Yes. By securing the timing chain tightly to the cam sprocket using heavy-duty zip ties and locking the tensioner through the side service cover, you can remove the cam sprocket and camshaft without disturbing bottom-end timing or pulling the front cover.
