Acura RL. Manual - part 423

Fig. 119: Removing Valve Guide
Courtesy of AMERICAN HONDA MOTOR CO., INC.

7. If a valve guide still won't move, drill it out with a 8 mm (5/16 in.) bit, then try again.

8. Remove the new guide(s) from the freezer, one at a time, as you need them.

9. Apply a thin coat of clean engine oil to the outside of the new valve guide. Install the guide from the

camshaft side of the head; use the special tool to drive the guide to the specified installed height (A)
of the guide (B). If you have all 12 guides to do, you may have to reheat the head.

Valve Guide Installed Height

Intake: 21.20-22.20 mm (0.835-0.874 in.)

Exhaust: 20.60-21.60 mm (0.811-0.850 in.)

NOTE:

Drill guides only in extreme cases; you could damage the cylinder head
if the guide breaks.

2007 Acura RL

2005-08 ENGINE Cylinder Head - RL

Friday, June 05, 2009 3:18:37 PM

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Fig. 120: Installing Valve Guide
Courtesy of AMERICAN HONDA MOTOR CO., INC.

10. Coat both the reamer and the valve guide with cutting oil.

11. Rotate the reamer clockwise the full length of the valve guide bore.

Fig. 121: Rotating Reamer Clockwise
Courtesy of AMERICAN HONDA MOTOR CO., INC.

12. Continue to rotate the reamer clockwise while removing it from the bore.

13. Thoroughly wash the guide in detergent and water to remove any cutting residue.

14. Check the clearance with a valve (see VALVE STEM-TO-GUIDE CLEARANCE

INSPECTION ). Verify that a valve slides in the intake and exhaust valve guides without sticking.

15. Inspect the valve seating. If necessary renew the valve seat using a valve seat cutter (see VALVE

SEAT RECONDITIONING ).

VALVE SEAT RECONDITIONING

2007 Acura RL

2005-08 ENGINE Cylinder Head - RL

Friday, June 05, 2009 3:18:37 PM

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1. Inspect valve stem-to-guide clearance (see VALVE STEM-TO-GUIDE CLEARANCE

INSPECTION ). If the valve guides are worn, replace them (see VALVE GUIDE
REPLACEMENT ) before cutting the valve seats.

2. Renew the valve seats in the cylinder head using a valve seat cutter.

Fig. 122: Removing Valve Seats In Cylinder Head Using Valve Seat Cutter
Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Carefully cut a 45° seat, removing only enough material to ensure a smooth and concentric seat.

4. Bevel the upper edge of the seat with the 30° cutter and the lower edge of the seat with the 67.5°

cutter (intake seat) or the 60° cutter (exhaust seat). Check the width of the seat and adjust accordingly.

Fig. 123: Identifying Valve Seats Cutter Angle
Courtesy of AMERICAN HONDA MOTOR CO., INC.

5. Make one more very light pass with the 45° cutter to remove any possible burrs caused by the other

cutters.

Valve Seat Width

Standard (New): 1.25-1.55 mm (0.049-0.061 in.)

Service Limit: 2.00 mm (0.079 in.)

6. After resurfacing the seat, inspect it for even valve seating. Apply Prussian Blue compound (A) to the

valve face. Insert the valve in its original location in the head, then lift it and snap it closed against the
seat several times.

2007 Acura RL

2005-08 ENGINE Cylinder Head - RL

Friday, June 05, 2009 3:18:37 PM

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Fig. 124: Identifying Prussian Blue Compound On Valve Face
Courtesy of AMERICAN HONDA MOTOR CO., INC.

7. The actual valve seating surface (B), as shown by the blue compound, should be centered on the seat.



If it is too high (closer to the valve stem), you must make a second cut with the 67.5° cutter
(intake seat) or the 60° cutter (exhaust seat) to move it down, then one more cut with the 45°
cutter to restore seat width.



If it is too low (closer to the valve edge), you must make a second cut with the 30° cutter to
move it up, then one more cut with the 45° cutter to restore seat width.

8. Insert the intake and exhaust valves in the head, and measure the valve stem installed height (A).

Intake Valve Stem Installed Height

Standard (New): 46.75-47.55 mm (1.841-1.872 in.)

Service Limit: 47.80 mm (1.882 in.)

Exhaust Valve Stem Installed Height

Standard (New): 46.68-47.48 mm (1.838-1.869 in.)

Service Limit: 47.73 mm (1.879 in.)

Fig. 125: Identifying Valve Stem Installed Height
Courtesy of AMERICAN HONDA MOTOR CO., INC.

NOTE:

The final cut should always be made with the 45° cutter.

2007 Acura RL

2005-08 ENGINE Cylinder Head - RL

Friday, June 05, 2009 3:18:37 PM

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