Cylinder Head Resurface

Remove, machine resurface, and reinstall cylinder heads on a 1966 Chevrolet Corvette 327ci V8, including valve train disassembly, head removal, gasket replacement, and reassembly with proper torque sequence.

Warnings

Tools required

Parts

• Cylinder head gasket set × 1 — Use OEM specification
• Intake manifold gasket set × 1 — Use OEM specification
• Exhaust manifold gaskets × 2 — Use OEM specification
• Valve cover gaskets × 2 — Use OEM specification
• Valve stem seals × 16 — Use OEM specification
• Head bolt set × 1 — Use OEM specification
• Intake manifold bolt set × 1 — Use OEM specification
• Exhaust manifold bolt set × 1 — Use OEM specification

Fluids

• 5W-30 Conventional Engine Oil — 5 qt
• DEX-COOL Extended Life Coolant (Orange) — 10 qt

Preparation

1. Disconnect negative battery cable and secure away from battery post
2. Drain cooling system completely into appropriate container by opening radiator petcock and removing radiator cap
3. Drain engine oil and replace oil filter
4. Remove air cleaner assembly and disconnect throttle linkage
5. Label and disconnect all vacuum lines, fuel lines, and electrical connections at carburetor and distributor
6. Position vehicle on level surface with parking brake engaged

Procedure

1. 1

   Remove valve covers and rocker arm assemblies
   Remove 4 valve cover bolts from each valve cover and lift off covers. Using a marking pen, number each rocker arm 1-16 according to position. Loosen rocker arm nuts evenly and remove rocker arm assemblies. Store rocker arms in numbered order on clean shop towels. Remove pushrods one at a time, marking their positions, and store them in order. Keep intake and exhaust pushrods separate.
2. 2

   Remove intake manifold
   Disconnect distributor cap and remove distributor (mark position before removal). Remove thermostat housing and upper radiator hose. Remove 12 intake manifold bolts working from outside toward center. Carefully lift intake manifold straight up to avoid damaging gasket surfaces. Clean gasket material from cylinder head surfaces using plastic scraper.
3. 3

   Remove exhaust manifolds
   Disconnect exhaust pipes from exhaust manifolds at flange connections. Remove 5 exhaust manifold bolts from each manifold working from center outward. Remove both exhaust manifolds and set aside. Inspect manifolds for cracks or warpage while removed.
4. 4

   Remove cylinder head bolts
   Remove all 17 cylinder head bolts from each head in reverse of tightening sequence (start from outer bolts working toward center). Use breaker bar if necessary but avoid impact tools. Keep bolts organized by cylinder head (left/right) for inspection.
5. 5

   Remove cylinder heads
   Carefully break cylinder heads loose from block using pry points at front corners (never pry between gasket surfaces). Lift each cylinder head straight up and place on clean padded surface with combustion chambers facing up. Remove and discard head gaskets. Mark each head LEFT or RIGHT for proper reinstallation.
6. 6

   Clean and inspect cylinder heads
   Thoroughly clean all carbon deposits from combustion chambers using wire brush and solvent. Clean all gasket surfaces on heads ensuring no material remains. Inspect for cracks in combustion chambers, valve seats, and between valve seats. Using straightedge and feeler gauge, check head surface flatness across length and width. Flatness must not exceed 0.003 inch across entire surface.
7. 7

   Disassemble valves (if replacing seals or performing valve job)
   Using valve spring compressor, compress each valve spring and remove valve keepers using magnetic tool. Slowly release spring tension and remove retainer, spring, and valve stem seal. Remove valve from combustion chamber side. Mark each valve with cylinder number and intake/exhaust position. Inspect valve stems for wear and valve faces for burning or pitting.
8. 8

   Transport heads to machine shop
   Transport both cylinder heads to qualified machine shop for resurfacing. Specify maximum material removal of 0.010 inch combined from both head and block. Request surface finish of 60-80 RMS for modern composition gaskets. Have shop perform magnaflux inspection for cracks. If valve work is needed, have shop perform valve seat grinding and valve grinding at this time.
9. 9

   Reassemble valves with new seals
   Lightly oil valve stems with assembly lube. Install each valve into its original guide from combustion chamber side. Install new valve stem seal over guide using appropriate driver or socket (do not hammer directly on seal). Install valve spring with closer-wound coils toward head. Compress spring and install retainer and keepers, ensuring keepers are fully seated in valve stem groove before releasing compressor.
10. 10

    Prepare block surface and install head gaskets
    Clean cylinder block deck surfaces thoroughly with plastic scraper and solvent. Verify block surface is clean and dry with no oil or coolant present. Check block flatness using straightedge. Clean all head bolt holes using wire brush and compressed air to remove any debris or oil. Chase threads with appropriate tap if necessary. Place new head gaskets on block with UP marking facing up. Align gaskets over dowel pins. Do not use sealant on composition gaskets unless specified by gasket manufacturer.
11. 11

    Install cylinder heads
    Carefully position each cylinder head onto block, aligning with dowel pins. Ensure head gasket remains properly positioned. Install all 17 head bolts finger tight. Apply light coat of engine oil or moly lube to head bolt threads and under bolt heads. Torque head bolts in three stages using proper sequence (start at center, work outward in spiral pattern): first pass to 25 ft-lbs, second pass to 50 ft-lbs, final pass to 65 ft-lbs. Allow engine to sit 30 minutes, then re-torque all bolts to final specification of 65 ft-lbs in sequence.
12. 12

    Install pushrods and rocker arms
    Install each pushrod into its original position, ensuring lower end seats properly in lifter cup. Apply assembly lube to rocker arm pivot balls and pushrod tips. Install rocker arms in original positions with pushrod ends seated in rocker arm cups. Thread rocker arm nuts finger tight. Rotate engine to position each valve at base circle (lifter on low lobe of cam) before adjusting. Adjust each valve to zero lash, then tighten nut one additional turn. Repeat for all 16 valves.
13. 13

    Install exhaust manifolds
    Position new exhaust manifold gaskets on cylinder heads. Install exhaust manifolds and start all 5 bolts per side finger tight. Torque exhaust manifold bolts to 25 ft-lbs working from center bolts outward. Reconnect exhaust pipes to manifold flanges using new gaskets and torque flange nuts to 35 ft-lbs.
14. 14

    Install intake manifold
    Apply thin bead of RTV silicone at front and rear block-to-head joints (china walls). Position new intake manifold gaskets on cylinder heads, ensuring all port openings align. Place new end seals at front and rear. Carefully lower intake manifold into position without disturbing gaskets. Install all 12 manifold bolts finger tight. Torque intake manifold bolts to 30 ft-lbs in sequence: start at center bolts and work outward in crisscross pattern. Reinstall thermostat housing with new gasket and torque to 20 ft-lbs.
15. 15

    Install valve covers and final assembly
    Install new valve cover gaskets in valve cover grooves. Position valve covers on heads and install 4 bolts per side. Torque valve cover bolts to 45 inch-lbs (3.75 ft-lbs) evenly to avoid distorting covers. Reinstall distributor in original position and reconnect cap. Reconnect all vacuum lines, fuel lines, electrical connections, and throttle linkage according to labels. Install air cleaner assembly.
16. 16

    Refill fluids and perform initial start
    Refill cooling system with 10 quarts of DEX-COOL coolant mixed 50/50 with distilled water. Refill crankcase with 5 quarts of 5W-30 conventional engine oil. Reconnect negative battery cable. Prime oil system by disconnecting coil wire and cranking engine for 15-20 seconds in 5-second intervals. Reconnect coil wire. Start engine and check immediately for oil pressure, coolant leaks, and unusual noises. Allow engine to reach operating temperature while monitoring for leaks. Check and adjust timing to specification. Recheck all fluid levels after test drive.

Reassembly

1. Retorque cylinder head bolts after first 500 miles of operation
2. Recheck valve lash adjustment after initial heat cycle and again at 500 miles
3. Retorque intake manifold bolts to specification after engine reaches operating temperature for the first time
4. Inspect all gasket surfaces for leaks after initial startup and again after 100 miles

Verification

• Engine should start readily and idle smoothly without unusual mechanical noise
• Oil pressure should register normal range (30-40 psi at idle, 50-60 psi at 2000 rpm) within 5 seconds of startup
• No coolant, oil, or vacuum leaks visible at cylinder heads, intake manifold, or valve covers
• Engine should reach normal operating temperature (180-195°F) without overheating
• Compression test should show even readings across all cylinders within 10% variance
• No excessive blowby visible from oil filler cap or PCV system
• Exhaust should be clean without blue smoke (oil burning) or white smoke (coolant)

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