Engine top End 5-19

NOTE

Camshaft, Camshaft Chain

ENGINE TOP END

CAUTION

The camshaft caps are machined with the cylinder head. So, if a cap is installed in a wrong location, the camshaft may seize because of improper oil clearance in the bearings.

CAUTION

• First tighten down the two camshaft cap bolts (#1 and #2
bolts in the figure) evenly to seat the camshafts in place,
then tighten all bolts following the specified tightening se­
quence.

Torque - Camshaft Cap Bolts: 12 N·m (1.2 kgf·m, 8.5 ft·lb)

• Install the head oil pipes.

Torque -Oil Pipe Bolts: 11 N·m (1.1 kgf·m, 95 in·lb)

• Install the camshaft chain tensioner (see Camshaft Chain Tensioner Installation).

• Check the chain timing.

Camshaft and Sprocket Assembly

OThe inlet and exhaust sprockets are identical.

• Install the sprockets so that the marked [A] ("IN" and "EX")
side faces to the left side.

Inlet sprocket must use "l" marked bolt holes. Exhaust sprocket must use "E" marked bolt holes.

• Apply a non-permanent locking agent to the camshaft
sprocket bolts and tighten them.

Torque - Camshaft Sprocket Bolts: 15 N·m (1.5 kgf·m, 11.0 ft·lb)

• If a new camshaft is to be used, apply a thin coat of a
molybdenum disulfide oil to the cam surfaces.

Camshaft, Camshaft Cap Wear

The journal wear is measured using plastigage (press gauge), which is inserted into the clearance to be mea­sured. The plastigage indicates the clearance by the amount it is compressed and widened when the parts are assembled.

• Cut strips of plastigage to journal width. Place a strip on each journal parallel to the camshaft with the camshaft in­stalled in the correct position and so that the plastigage will be compressed between the journal and camshaft cap.

• Install the camshaft caps, tightening the bolts in the cor­rect sequence.

Torque -Camshaft Cap Bolts: 12 N-m (1.2 kgf-m, 8.5ft-lb)

O Do not turn the camshaft when the plastigage is be­tween the journal and camshaft cap.

• Remove the camshaft caps again, and measure the plas-tigage width [A] to determine the clearance between each journal and camshaft cap. Measure the widest portion of the plastigage. Plastigage Scale [B]

• If any clearance exceeds the service limit, measure the camshaft journal diameter and the camshaft bearing in­side diameter.

• If any of the measurements is beyond the service limit, replace the worn part and check the clearance again.

Camshaft Journal, Camshaft Cap Clearance
Standard: 0.030 ~ 0.071 mm (0.0012 ~ 0.0028 in.)

Service Limit: 0.16 mm (0.006 in.)

Camshaft Chain Guide Wear

• Visually inspect the rubber [A] on the guides.

• If the rubber is damaged or cut, replace the guides.

Дата добавления: 2014-12-23