Acura Coupes and Sedans 1986-1993 Repair Guide

Camshafts and Rocker Shafts

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REMOVAL & INSTALLATION



Integra

See Figures 1 through 5

  1. Disconnect the negative battery cable. Remove the timing belt cover and cylinder head cover.
  2.  
  3. Rotate the crankshaft to TDC of No. 1 piston and remove the timing belt.
  4.  
  5. Remove the camshaft sprockets.
  6.  
  7. To check camshaft end-play:
  8.  



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Fig. Fig. 1: Camshaft holder positioning and identification-1986-90 Integra



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Fig. Fig. 2: Installing the camshaft holder bolts-1986-90 Integra

    1. Loosen the valve adjusters to remove as much spring tension as possible.
    2.  
    3. Loosen the end bearing cap bolts 1 turn.
    4.  
    5. Install the dial indicator.
    6.  
    7. Push the camshaft fully towards the back of the head, zero the dial indicator and push the camshaft fully the other way to read end-play.
    8.  
    9. End-play on a new camshaft should be 0.002-0.006 in. (0.05-0.15mm), 0.020 in. (0.5mm) is the service limit.
    10.  


  1. To remove the camshaft bearing caps, loosen each bolt 2 turns at a time in a crisscrosss pattern to avoid damage to the valves or rockers. Mark the caps so they can be replaced in their original position.
  2.  
  3. Lift the camshafts from the cylinder head, wipe them clean and inspect the lift ramps. Replace the camshafts and rockers if the lobes are pitted, scored or excessively worn.
  4.  



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Fig. Fig. 3: Camshaft and valve components-1991-93 Integra 1.8L



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Fig. Fig. 4: Camshaft holder positioning and identification-1991-93 Integra 1.8L



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Fig. Fig. 5: Camshaft and valve components-1991-93 Integra 1.7L

  1. Use Plasti-gauge ® to check bearing clearance: 0.002-0.004 in. (0.050-0.089mm) is standard clearance, 0.006 in. (0.15mm) service limit. If the clearance is too large and a new camshaft does not bring the clearance into specification, the cylinder head must be replaced.
  2.  

To install:
  1. Check the following before installing the camshafts:
    1. Be certain the keyways on the camshafts are facing UP (No. 1 cylinder at TDC).
    2.  
    3. The valve adjuster locknuts should be loosened and the adjusting screws backed off before installation.
    4.  
    5. Replace the rocker arms in their original positions.
    6.  

  2.  
  3. Place the rocker arms on the pivot bolts and the valve stems.
  4.  
  5. Install the camshafts with the seals part way on the camshaft, open side (spring) facing in. Lubricate the lip of the seal.
  6.  
  7. Do not apply oil to the holder mating surface of the camshaft seals.
  8.  
  9. Apply liquid gasket to the head mating surfaces of the No. 1 and No. 6 camshaft holders then install them along with the remaining holders.
  10.  
  11. Begin tightening the camshaft holder bolts, 2 turns at a time while making sure the rocker arms are positioned on the valve stems. Use a crisscrosss pattern when turning the bolts.
  12.  
  13. Using an oil seal driver tool 07947-SB00100 or equivalent, press new oil seals into the No. 1 camshaft holders.
  14.  
  15. Torque the bolts in the same pattern to 9 ft. lbs. (12 Nm) on 1986-90 models, 7 ft. lbs. (10 Nm) on 1991-93 1.8L engine models. On 1991-93 1.7L V-TEC models, torque the 8mm bolts to 16 ft. lbs. (22 Nm) and the 6mm bolts to 8 ft. lbs. (11 Nm). Check that the rockers do not bind on the valves.
  16.  
  17. Install the camshaft pulley keys onto the grooves in the camshafts.
  18.  
  19. Push the camshaft pulleys onto the camshafts, then torque the retaining bolts to 27 ft. lbs. (38 Nm).
  20.  
  21. Install the timing belt, adjust the valves and pour oil over the camshafts before finishing the assembly.
  22.  

1986-90 Legend

See Figures 6, 7, 8 and 9

  1. Disconnect the negative battery cable. Remove the timing belt covers and cylinder head covers.
  2.  
  3. Rotate the crankshaft to TDC of No. 1 piston and remove the timing belt.
  4.  
  5. Remove the camshaft sprockets.
  6.  
  7. To check camshaft end-play:
    1. Loosen the valve adjusters to remove as much spring tension as possible.
    2.  
    3. Loosen the end bearing cap bolts 1 turn.
    4.  
    5. Install the dial indicator.
    6.  
    7. Push the camshaft fully towards the back of the head, zero the dial indicator and push the camshaft fully the other way to read end-play.
    8.  
    9. End-play on a new camshaft should be 0.002-0.006 in. (0.05-0.15mm), 0.020 in. (0.5mm) is the service limit.
    10.  

  8.  
  9. To remove the camshaft bearing caps, loosen each bolt 2 turns at a time in a crisscrosss pattern to avoid damage to the valves or rockers. Mark the caps so they can be replaced in their original position.
  10.  
  11. Lift the camshafts from the cylinder head, wipe them clean and inspect the lift ramps. Replace the camshafts and rockers if the lobes are pitted, scored or excessively worn.
  12.  



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Fig. Fig. 6: Camshaft holder bolt torque sequence and specifications-1991-93 Integra 1.7L



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Fig. Fig. 7: Camshaft and bearing removal-1986-90 Legend



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Fig. Fig. 8: Rocker arm and push rod removal-1986-90 Legend



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Fig. Fig. 9: Camshaft bearing cap torque sequence-1986-90 Legend

  1. Use Plasti-gauge ® to check bearing clearance: 0.002-0.004 in. (0.050-0.089mm) is standard clearance, 0.006 in. (0.15mm) service limit. If the clearance is too large and a new camshaft does not bring the clearance into specification, the cylinder head must be replaced.
  2.  

To install:
  1. Fill the hydraulic lifter mounting holes with engine oil and install the lifters. Do not rotate the lifters while installing them. Also pour oil into the oil passages and fillers in the cylinder head.
  2.  
  3. With all the adjusting screws loose, install the pushrods and rocker arms in their original positions.
  4.  
  5. Advance the crankshaft 15 degrees, slip the camshaft seals onto the camshafts and lay the camshafts into the heads. Set the front camshaft so both valves on the No. 1 cylinder are be closed. Set the rear camshaft to make sure the No. 4 cylinder exhaust valve is closed.
  6.  
  7. Apply liquid gasket sealer to the camshaft oil seal mounting surface and on the end bearing cap-head contact surface. Install the caps in their original position and tighten each cap bolt 2 turns at a time in the sequence shown to draw the camshaft down evenly against the valve springs.
  8.  
  9. Make sure the oil seal is properly positioned and torque the bolts in 2 steps in sequence to 20 ft. lbs. (28 Nm). Torque the 6mm bolts last to 9 ft. lbs. (12 Nm).
  10.  
  11. Install the upper timing belt cover plate.
  12.  
  13. Install the camshaft pulleys and torque the bolts to 23 ft. lbs. (32 Nm).
  14.  
  15. Install the timing belt, adjust the valves and pour oil over the camshafts before completing the assembly.
  16.  

1991-93 Legend and Vigor

See Figures 10 through 15



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Fig. Fig. 10: Camshaft holder bolt loosening sequence-1991-93 Legend



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Fig. Fig. 11: Camshaft holder bolt torque sequence-1991-93 Legend



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Fig. Fig. 12: Rocker arm and shaft assemblies-1991-93 Legend

  1. Disconnect the negative battery cable. Remove the timing belt covers and cylinder head covers.
  2.  
  3. Rotate the crankshaft to TDC of No. 1 piston and remove the timing belt.
  4.  
  5. Remove the camshaft sprockets.
  6.  
  7. Loosen the rocker shaft holder bolts 1 turn at a time in the opposite of the installation sequence. This is the only way to avoid damaging the valves, camshafts or rocker assemblies.
  8.  
  9. After all bolts are loose, remove the rocker arm shafts as an assembly with the bolts still in the holders.
  10.  
  11. If the rocker shafts are to be disassembled, note that each rocker arm has a letter A or B stamped into the side. Before disassembling the rocker arms, make a note of the position of each letter so they can be reassembled the same way. On Vigor, the springs between the rocker arms are not all the same length. Carefully note their positions during disassembly.
  12.  
  13. On Legend, do not remove the hydraulic tappets from the rocker arms unless they are to be replaced. Handle the rocker arms carefully so the oil does not drain out of the tappets.
  14.  
  15. Lift the camshafts from the cylinder head, wipe them clean and inspect the lift ramps. Replace the camshafts and rockers if the lobes are pitted, scored or excessively worn.
  16.  
  17. To check camshaft end-play, reinstall the holders without the rocker arm assembly and torque the bolts in sequence. End-play should be 0.002-0.006 in (0.05-0.15mm) on a new camshaft. The maximum service limit is 0.020 in. (0.5mm).
  18.  
  19. Use Plasti-gauge ® to check bearing clearance: 0.002-0.004 in. (0.050-0.089mm) is standard clearance, 0.006 in. (0.15mm) service limit. If the clearance is too large and a new camshaft does not bring the clearance into specification, the cylinder head must be replaced.
  20.  

To install:
  1. Place a new camshaft seal on the end of the camshaft, lubricate the journals and set the camshaft in place on the head.
  2.  
  3. Apply liquid gasket to the mounting surfaces of the end camshaft holders.
  4.  



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Fig. Fig. 13: Camshaft holder bolt removal sequence-Vigor



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Fig. Fig. 14: Camshaft holder bolt torque sequence-Vigor



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Fig. Fig. 15: Rocker shaft assemblies-Vigor

  1. Set the rocker arm assemblies in place and start all the cam holder bolts. Make sure the rocker arms are properly positioned and turn each bolt in sequence 1 turn at a time until the holders are seated on the head. This is the only way to avoid damaging the valves or rocker assemblies.
  2.  
  3. When all the camshaft and rocker holders are seated, torque the bolts in the same sequence. Torque the 8mm bolts to 16 ft. lbs. (22 Nm) and the 6mm bolts to 9 ft. lbs. (12 Nm).
  4.  
  5. Install the camshaft pulleys and torque the bolts to 23 ft. lbs. (32 Nm).
  6.  
  7. Install the timing belt, adjust the valves and pour oil over the camshafts before completing the assembly.
  8.  

INSPECTION



Degrease the camshaft using safe solvent, clean all oil grooves. Visually inspect the cam lobes and bearing journals for excessive wear. If a lobe is questionable, check all lobes and journals with a micrometer.

Measure the lobes from nose to base and again at 90°. The lift is determined by subtracting the second measurement from the first. If all exhaust lobes and all intake lobes are not identical, the camshaft must be reground or replaced. Measure the bearing journals and compare to specifications. If a journal is worn there is a good chance that the cam bearings are worn too, requiring replacement.

If the lobes and journals appear intact, place the front and rear cam journals in V-blocks and rest a dial indicator on the center journal. Rotate the camshaft to check for straightness, if deviation exceeds 0.025mm, replace the camshaft.

 
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