Mitsubishi 6M70 Cylinder Head Parts Page and Valve Train Parts Page, Valve Adjustment Procedure and Valve Lash Clearance page 1 of 7 Mitsubishi 6M70 Inspection and Adjustment of Valve Clearances Service standards
Location –
Maintenance item Valve clearance (when engine is cold)
Standard value
Limit
Remedy
Intake side
0.4 MM / .016 Inch
–
Adjust
Exhaust side
0.6 MM / .025 Inch
–
Adjust
Tightening torque Mark
Parts to be tightened
Tightening torque
Remarks
–
Lock nut (valve bridge adjusting screw tightening)
68 Nm { 7 kgfm } 50 Ft Lbs
–
–
Lock nut (rocker arm adjusting screw tightening)
60 Nm { 6 kgfm } 44 Ft Lbs
–
• Valve clearances should be checked and adjusted as follows while the engine is still cold.
10
5
16
[Inspection] • Remove the rocker cover. • Bring the No. 1 or No. 6 cylinder piston to the top dead center (TDC) on the compression stroke according to the following procedure: • Crank the engine until the pointer is aligned with the “1 6” mark on the flywheel. • This will place either the No. 1 or No. 6 cylinder piston at TDC on the compression stroke. The cylinder in which the rocker arms for both the intake and exhaust valves can be pushed down by hand by the valve clearance amounts has its piston at TDC. Rotate the engine by one full turn to switch the TDCs of the No. 1 and No. 6 cylinder pistons. • With the No. 1 or No. 6 cylinder piston at TDC, measure the clearance of the valves (clearance between valve bridge and pad) marked with a circle in the table below. Cylinder No. Valve
1
2
3
4
5
6
IN EX IN EX IN EX IN EX IN EX IN EX
No. 1 cylinder piston at TDC on O compression stroke
O
O
–
–
O
O
–
–
O
–
–
No. 6 cylinder piston at TDC on compression stroke
–
–
O
O
–
–
O
O
–
O
O
–
• Any attempt to insert a feeler gauge without first securing sufficient space, as described above, between the pad and the valve bridge will fail, as the pad will tilt as shown in the illustration, thus blocking the entry of a feeler gauge.
Mitsubishi 6M70 Engine Parts contact email: EngineParts@HeavyEquipmentRestorationParts.com Contact phone: 269 673 1638
Mitsubishi 6M70 Cylinder Head Parts Page and Valve Train Parts Page, Valve Adjustment Procedure and Valve Lash Clearance page 2 of 7 • Before inserting a feeler gauge, push the adjusting screw pad on the side opposite from where a feeler gauge is to be inserted, as shown in the illustration, using a flat-blade screwdriver or other similar tool. This will create space necessary for the gauge to be inserted. • The measurement is correct when the feeler gauge feels slightly resisted as it is inserted. • The measurement is not yet correct if the feeler gauge can still be inserted smoothly. • If the measurement deviates from the standard value, adjust as follows. [Adjustment] • Loosen the lock nuts and adjusting screws on the valve bridge and rocker arm.
• While holding the valve bridge by hand, screw in the adjusting screw until it lightly contacts the valve stem end. • Then, further screw in the adjusting screw by 45°.
• While holding the adjusting screw in this position, tighten the lock nuts to the specified torque.
CAUTION • After adjusting the adjusting screw, be sure to tighten the lock nut to the specified torque. Insufficient torquing will compromise the parallelism of the valve bridge, damaging the valve mechanism.
Mitsubishi 6M70 Cylinder Head Parts Page and Valve Train Parts Page, Valve Adjustment Procedure and Valve Lash Clearance page 3 of 7 • Screw in or out the adjusting screw on the rocker arm until the correct feeler gauge can be inserted with a slight resistance. • After adjustment, while holding the adjusting screw in this position with a screwdriver, tighten the lock nuts to the specified torque. • Recheck the valve clearance using the correct feeler gauge.
CAUTION • If the valve clearance has been adjusted, be sure to check and adjust the Powertard clearance. • After the adjustment is complete, install the rocker cover and the gasket.
Mitsubishi 6M70 Cylinder Head Parts Page and Valve Train Parts Page, Valve Adjustment Procedure and Valve Lash Clearance page 4 of 7
Mitsubishi 6M70 Timing Gearing Valve Train Parts page
Mitsubishi 6M70 Engine Parts contact email: EngineParts@HeavyEquipmentRestorationParts.com Contact phone: 269 673 1638
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Mitsubishi 6M70 Cylinder Head Parts Page and Valve Train Parts Page, Valve Adjustment Procedure and Valve Lash Clearance page 5 of 7 Mitsubishi 6M70 Cylinder Head, Rocker and Shaft, Camshaft, Rocker Case and Cylinder Head Gasket
Mitsubishi 6M70 Valve Mechanism
Mitsubishi 6M70 Intake Valves Exhaust Valves intake Valve Guides Exhaust Valve Guides
Valve Bridge Intake Rocker Arm Exhaust Rocker Arm Rocker Shaft Camshaft
Valve Cotters, Keepers, Inner Valve Springs Outer Valve Springs Upper Retainers Valve Stem Seals
Mitsubishi 6M70 Cylinder Head Parts Page and Valve Train Parts Page, Valve Adjustment Procedure and Valve Lash Clearance page 6 of 7
Mitsubishi 6M70 Injectors Installation
Injector Bolt
• • • •
Injector hold down bolt tightening torque 40 Ft Lbs Fuel injector line to cylinder head tightening torque 23 Ft Lbs Fuel Return Line Hollow bolt to cylinder head tightening torque 29 Ft Lbs Rocker cover bolt tightening torque 6.5 Ft Lbs
Mitsubishi 6M70 Cylinder Head Parts Page and Valve Train Parts Page, Valve Adjustment Procedure and Valve Lash Clearance page 7 of 7 • Remove oil or any other contamination from the surfaces where sealant is to be applied. • Install the cylinder head gasket onto the crankcase and apply sealant to the illustrated section of the cylinder head gasket. • Within three minutes following the application, install the cylinder head onto the cylinder head gasket. Take care not to spread the sealant beyond the application areas during installation.
CAUTION • Do not start the engine for at least an hour after installation. • Whenever the cylinder head bolts are subsequently loosened or removed, the cylinder head gasket must be replaced and sealant reapplied upon reassembly. • If pistons, connecting rods or other relevant parts are replaced, measure to check the pistons for any change in protrusion.
• Tighten the four peripheral cylinder head bolts to a torque of 5 Ft Lbs • Tighten the 6M70 head bolts in the tightening sequence shown on this page. • 6M70 head bolt tightening torque133 Ft Lbs plus 90 degrees
• Turn the holder of nal spring.
counterclockwise to pretension the inter-
• Set the tool such that the rod (extension) is pressed against the rocker shaft bracket by the force of the spring. • Align any line on the holder scale with any line on the socket scale. (This will be used as the reference point = 0°.) • From the reference point, turn the socket by 90° in the direction shown. Each division on the holder scale represents 5°. • After tightening the cylinder head bolt within the plastic region, make a punch mark on the bolt head to record the number of times that they have been tightened.
CAUTION A copy of the Mitsubishi 6M70 workshop manual is available here: www.6M70.com
• The bolts should be tightened within the plastic region. Never tighten them further than the specified angle.
Mitsubishi 6M70 Engine Parts contact email: EngineParts@HeavyEquipmentRestorationParts.com Contact phone: 269 673 1638