B2300 Mazda MX-5 NB рестайлинг

Valve train is a "set-for-life" system, consisting of maintenance-free, direct-acting mechanical bucket tappets. Tappets are selective and would only require replacement with cylinder head repair or replacement. See appropriate article in ENGINES.

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

1. Disconnect negative battery cable.
2. Remove right front tire.
3. Remove right splash shield.
4. Remove spark plug cover plate.
5. Remove high-tension leads.
6. Remove spark plugs.
7. Disconnect Oil Control Valve (OCV) 2-pin harness connector.
8. Remove ventilation hose.
9. Remove cylinder head cover.
10. Rotate crankshaft clockwise until No. 1 piston is at TDC of compression stroke. Measure valve clearance between base of camshaft lobe and valve tappets at "A". (Scheme 9) See «VALVE CLEARANCE SPECIFICATIONS»(ref-151874-S36037188242003010800000) table. If clearance is not as specified, record valve location and clearance reading. Go to next step. VALVE CLEARANCE SPECIFICATIONS Application (1) In. (mm) B2300 (2) B3000 & B4000 (3) Intake.009-.011 (.22-.28) Exhaust.011-.013 (.27-.33) Mazda6 3.0L (3) 2.3L Intake.009-.011 (.22-.28) Exhaust.011-.013 (.27-.33) Miata Intake.007-.009 (.18-.24) Exhaust.011-.013 (.28-.34) MPV (3) Protege & Protege5.009-.012 (.23-.30) Tribute 2.0L Intake.004-.007 (.11-.18) Exhaust.011-.013 (.27-.34) 3.0L (3) (1) Adjust valves with engine cold. (2) Valve clearance is not adjustable. If valve clearance is not within specification, see appropriate article in ENGINES. (3) Engines are equipped with hydraulic valve lash adjusters. Valve clearance is not adjustable.
11. Rotate crankshaft clockwise about 360 degrees, positioning No. 4 piston at TDC of compression stroke. Measure valve clearance between base of camshaft lobe and valve tappets at "B". (Scheme 9) See «VALVE CLEARANCE SPECIFICATIONS»(ref-151874-S36037188242003010800000) table. If clearance is not within specification, Go to next step. If all valve clearances are as specified, go to step 42.
12. Remove drive belt.
13. Remove front drive shaft (RH) from joint shaft. Refer to REMOVAL & INSTALLATION in appropriate DIFFERENTIALS & AXLESHAFTS article in DRIVELINE/AXLES.
14. Remove engine front cover lower blind plug. (Scheme 10)
15. Remove engine front cover upper blind plug. (Scheme 11)
16. Remove cylinder block lower blind plug. (Scheme 12)
17. Install Crankshaft TDC Timing Peg (303-507). (Scheme 13)
18. Rotate crankshaft clockwise until crankshaft is in No. 1 cylinder TDC position (until balance weight is contacting Crankshaft TDC Timing Peg).
19. Loosen timing chain: Unlock chain tensioner ratchet using a suitable screwdriver or equivalent tool. Rotate exhaust camshaft clockwise using a suitable wrench on cast hexagon and loosen a timing chain. Placing suitable bolt (6 mm X 25-35 mm) at engine front cover upper blind plug, secure chain guide at position where tension is released. (Scheme 14)
20. Hold exhaust camshaft using a suitable wrench on cast hexagon and remove exhaust camshaft sprocket. (Scheme 15)
21. Loosen camshaft cap bolts in two or three steps in order. (Scheme 16) Remove camshaft caps.
22. Remove camshaft.
23. Remove tappet.
24. Select proper adjustment shim: New Adjustment Shim Measure removed shim. Add shim thickness, plus measured valve clearance, minus standard valve clearance. Standard Valve Clearance (Engine Cold) Intake:.010" (.25 mm), Exhaust:.012" (.30 mm).
25. Install camshaft and No. 1 cylinder aligned with TDC position.
26. Tighten camshaft cap bolts in order to following torque: Tighten to 44-80 INCH lbs. (5-9 N.m). (Scheme 17) Tighten to 124-150 INCH lbs. (14-17 N.m).
27. Install exhaust camshaft sprocket. NOTE: Do not tighten bolt for camshaft sprocket during this step. First confirm valve timing, then tighten bolt.
28. Install Camshaft Alignment Tool (49-UN30-3465) to camshaft. (Scheme 18)
29. Remove (6 mm X 25-35 mm) bolt from engine front cover to apply tension to the timing chain.
30. Turn crankshaft clockwise until crankshaft is in No. 1 cylinder TDC position (until balance weight is contacting Crankshaft TDC Timing Peg).
31. Hold exhaust camshaft using a suitable wrench on cast hexagon as shown.
32. Tighten exhaust camshaft sprocket lock bolt. Tightening torque is 66-70 ft. lbs. (89-95 N.m).
33. Remove Camshaft Alignment Tool (49-UN30-3465) from camshaft.
34. Remove Crankshaft TDC Timing Peg from block lower blind plug.
35. Rotate crankshaft two times clockwise until crankshaft is in TDC position. Reinstall camshaft alignment tool to camshaft and crankshaft TDC timing peg in cylinder block and inspect valve timing. If not aligned, loosen crankshaft pulley lock bolt and repeat from step 16).
36. Apply silicone sealant to engine front cover upper blind plug.
37. Install engine front cover upper blind plug. Tightening torque 71-102 INCH lbs. (8-11.5 N.m).
38. Install cylinder block lower blind plug. Tightening torque is 24-30 ft. lbs. (18-22 N.m).
39. Install new engine front cover lower blind plug. Tightening torque is 89-124 INCH lbs. (10-14 N.m).
40. Connect right front drive shaft and joint shaft.
41. Install drive belt.
42. Install cylinder head cover.
43. Install ventilation hose.
44. Install OCV 2-pin harness connector.
45. Install high-tension leads.
46. Install spark plugs.
47. Install spark plug cover plate.
48. Install right splash shield.
49. Install right front tire.

Scheme 18

Scheme 19

Scheme 20

Scheme 21

1. Ensure engine is cold. Remove valve cover. Rotate crankshaft clockwise until No. 1 piston is at TDC of compression stroke. Measure valve clearance between base of camshaft lobe and valve tappets at "A". (Scheme 9) See «VALVE CLEARANCE SPECIFICATIONS»(ref-151874-S36037188242003010800000) table. If clearance is not within specification, record valve location and clearance reading. Go to next step.
2. Rotate crankshaft clockwise about 360 degrees, positioning No. 4 piston at TDC of compression stroke. Measure valve clearance between base of camshaft lobe and valve tappets at "B". (Scheme 9) See «VALVE CLEARANCE SPECIFICATIONS»(ref-151874-S36037188242003010800000) table. If clearance is not within specification, Go to next step.
3. Turn crankshaft clockwise so that camshaft lobe on valve requiring clearance adjustment is positioned straight up, away from valve. Remove appropriate camshaft cap bolts as necessary. (Scheme 19) See «CAMSHAFT BOLT REMOVAL»(ref-151874-S22351201382003010800000) table. NOTE: For No. 2 and 3 cylinder exhaust valve adjustment shim removal, remove bolts "A" or "C". For No. 2 and 3 cylinder intake valve adjustment shim removal, remove bolts "B" or "D".
4. Assemble Adjustment Tool Shaft, Clamp and Bolt (49-T012-002, 49-T012-003 and 49-T012-004), aligning marks on adjustment tool. (Scheme 20) Install shaft and clamp on appropriate camshaft using camshaft cap bolts. (Scheme 19) Tighten cap bolts to 100-126 INCH lbs. (11.3-14.2 N.m). (Scheme 21) Tighten clamp bolt to secure shaft. (Scheme 20)
5. Mount Tappet Holder Body (49-T012-001A) on shaft toward outside of head over tappet requiring shim replacement. (Scheme 21) Position notch of tappet so that thin-blade screwdriver can be inserted. see scheme 14 Set body on tappet and align by its notch. Tighten short bolt to secure body to shaft. CAUTION: Use caution when depressing tappet. Cylinder head can be damaged by body tip when tappet is depressed.
6. Tighten long bolt on tappet holder body to depress tappet. Using thin-blade screwdriver, pry up on adjustment shim through notch on tappet. Using a magnet, remove shim and measure shim thickness. Select proper adjustment shim to obtain clearance within specification. Push selected shim into tappet. Loosen long bolt to allow tappet to move up. Loosen short bolt and remove body. Remove shaft and clamp. Install camshaft cap bolts and tighten to 100-126 INCH lbs. (11.3-14.2 N.m). Recheck valve clearance.

CAMSHAFT BOLT REMOVAL