Cylinder head of the GLA engine (Escort 3)

Features of the device

The cylinder head is cast (Fig. 2.50) from cast iron and has wedge-shaped combustion chambers. The in-line valves are installed at an angle of 15° from the vertical and are actuated by pushers, rods and rocker arms from the camshaft located in the cylinder block. The combustion chamber volume is 26.888-29.888 cm³. The head body has holes for the pusher rods, guide bushings and valve seats. The gasket is installed with the "Top" mark towards the head.



The valve seats have a working chamfer angle of 44°30'-45°. The width of the working chamfer of the seat is 1.2-1.75 mm for intake valves. 1.5-1.7 mm for exhaust valves.

The valve guide bushings are made of special cast iron and pressed into the cylinder head. The diameter of the holes in the bushings is 7.907-7.938 mm. The outer diameter of the nominal bushing size is 13.081-13.094 mm. The valves are made of special steel.



Valve springs are the same for inlet and outlet valves, each with six coils. Spring inner diameter, mm: 20.25-20.75 mm, wire diameter 3.77-3.83 mm. Spring height in free state is 42 mm.

The rocker arms are made of steel, the tappets are made of hardened steel. The nominal diameter of the tappets is 13.081-13.094 mm. The clearance in the "tappet-hole" connection is 0.016-0.062 mm.

Adjusting clearances in the valve drive mechanism

This operation is performed on a cold engine using the "rocking" method. Turn the crankshaft until the mark on its pulley aligns with the TDC mark on the timing mechanism drive cover. Remove the air filter and cylinder head cover. Rock the crankshaft pulley in both directions. Determine by the movement of the rocker arms. The valves of which cylinder (1st or 4th) are pressed by the rocker arms. If these are the rocker arms of the 1st cylinder, then adjust the clearances of the 4th cylinder and vice versa. After this, turn the crankshaft exactly 180° and adjust the clearances of the 2nd (or 3rd) cylinder. The firing order of the cylinders is shown in Table 1.3, and the procedure for adjusting the clearances in the valve drive mechanism is given in Table 2.7.

NOTE: The adjusting screws with rectangular threads have significant tension in the rocker arm. To avoid breakage of the screw, it is necessary to use a spanner wrench that ensures uniform distribution of force on the screw head, and a drill of the appropriate diameter, installed in the screw head (Fig. 2.51). In case of breakage of the screw head, replace the rocker arm assembly.

Removing and installing the cylinder head

After removing the power unit from the car, remove the valve cover, rocker shaft, then remove the rods, put them in order; unscrew the mounting bolts and remove the cylinder head and gasket. When assembling the cylinder head, the gasket must be dry, clean and installed with the mark facing the head. Pay attention to the alignment of the holes for the passage of oil in the gasket with the channels in the head (Fig. 2.52).



Install the cylinder head, screw in the mounting bolts by hand. Tighten the cylinder head mounting bolts in the order shown in Fig. 2.14 in four stages: 1st stage 1.0-1.5 kgf·m; 2nd reception 4.0-5.0 kgf·m; 3rd reception 8.0-9.0 kgf·m; Step 4 — 20 minutes after the 3rd step, tighten the bolts to a torque of 10.0-11.0 kgf·m. Install the pushrods, having previously dipped their ends in engine oil. Install the rocker arm axle and tighten the mounting bolts to a torque of 3.4-4.0 kgf·m. Adjust the clearances in the valve drive mechanism. Screw in and tighten the spark plugs to a torque of 1.5-2.0 kgf·m.

Disassembly and assembly of the cylinder head

Using a special device, compress the valve springs and remove the valve crackers. Then remove the spring plate, spring, and lower support washer. Remove and lay out the valves in order. Check the technical condition of the guide bushings (Fig. 2.53), valve seats, and working chamfers (see Table 2.6).





In case of significant wear, repair the parts. To ream the hole in the guide bushing for the valve of the repair size, it is necessary to use the reamer 21.042 (Fig. 2.54).



To do this, install the cylinder head with the seats facing up and gradually insert the tool into the guide hole, generously lubricating the reamer with special oil or kerosene. In case of excessive wear of the guide bushings, which cannot be eliminated with reamer 21.042, replace the cylinder head. After checking the guide bushings and their possible repair, check and, if necessary, restore the working chamfer of the valve seats. When processing the seat chamfer, use a specialized tool that centers the cutter or grinding stone relative to the seat. Do not allow the working chamfer to become faceted or scratched. Thoroughly clean and blow out the cylinder head with compressed air. After repairing the valve seats, grind the valve chamfers or replace the valves. In both cases, grind the valves to the seats with fine-grained grinding paste. After grinding, the valves should not change places. In case of installation of a new cylinder head and working valves, their grinding is mandatory. After grinding the valves, thoroughly wash and blow out the cylinder head with compressed air.

Disassembling and assembling the rocker arm axle

Remove the cotter pin, spring and thrust washer from the end of the rocker arm shaft. Remove the tappets, supports and spacer springs. If the supports are difficult to remove, you can use a mallet with a plastic striker. Lay out the parts in order. Rinse in trichloroethylene and check their technical condition: wear of the rocker arm shaft, fit of the rocker arm tips to the ends of the valve stems, condition of the support washers and thrust springs. If necessary, replace defective parts: grind the rocker arm tips if they have nicks. Assemble the rocker arm shaft in the reverse order of disassembly, lubricating all parts with engine oil. Pay attention to the alignment of the lubrication channels: they should be directed downwards and forward (Fig. 2.56).

NOTE: If installing a new rocker arm shaft, ensure that the plug is present on the timing drive side.

Before assembling the cylinder head, make sure all parts are clean. Lubricate the ends of the valve stems with engine oil and install them in the corresponding holes in the head. Lock the valves in the closed position using a suitable plate and install new oil deflector caps on the valve stems (Fig. 2.55) in the following order: wipe the valve stems with a lint-free cloth, wind adhesive tape into the grooves under the crackers, lubricate the valve stems and oil deflector caps with oil, install the caps until they stop and remove the adhesive tape.





In case of incorrect installation of oil deflector caps, oil consumption increases. Install the lower spring support washers, springs, upper spring plates, compress the springs with a special device and install crackers, paying attention to their correct position. Oil deflector caps can be replaced without removing the cylinder head from the engine. To do this, you need to have a device for fixing valves 21.056 and for compressing valve springs 21.057.


Disconnect the negative cable from the battery. Remove the air filter with the bracket. Disconnect the wires from the spark plugs, remove the cylinder head cover. Unscrew the spark plugs and remove the rocker shaft. Screw the valve locking device into the spark plug hole, turn its central pin, move it to the valve head and lock it in this position. Install the valve spring compressor 21.057 with an emphasis on the rocker shaft mounting bolt, as shown in Fig. 2.57.



Compress the valve spring and remove the crackers (preferably with a magnet to prevent them from falling into the engine). Release the spring and remove the upper spring plate, spring and oil deflector cap. Wind adhesive tape into the annular grooves of the valve, lubricate the valve stem and new oil deflector cap and install it on the valve. Remove the adhesive tape. Install the washer, spring, valve plate. Compress the spring with a device and install the crackers. Repeat the operation for the remaining valves. After replacing the oil deflector caps, install the rocker arm shaft and adjust the clearance in the valve drive mechanism. Install the remaining removed parts.

Camshaft and its drive (except for the GLA engine)

The engines use a cast iron camshaft mounted on five bearings in the cylinder head and driven by a toothed belt from the engine crankshaft. The camshaft is held from axial movement by a thrust flange attached to the cylinder head with two bolts.

The toothed belt of the camshaft drive of the Motorcraft 81 SM 6268 GE brand is tensioned by a roller tensioner. The tension moment of the toothed belt is 3.0-4.2 kgf·m for GMA, GPA, JPA engines. LPA and LUA 2.0-3.2 kgf·m. Since 1982, the value of the toothed belt tension has been changed and is 6.0-6.5 kgf·m for GMA, GPA, JPA engines. LPA, LUA, LRA and L7 4.5-5.0 kgf·m.

Removing and installing the camshaft

Disconnect the negative cable from the battery, disconnect the crankcase ventilation hose and the hoses from the intake manifold and cylinder head cover. Remove the air filter and disconnect the vacuum hose. Remove the windshield washer reservoir. Disconnect the high-voltage wires and remove the distributor sensor. Remove the fuel pump with gasket and pusher. Remove the clamp and disconnect the throttle cable from the bracket on the carburetor. Remove the crankcase ventilation hose from the branch pipe on the cylinder block, then the cylinder head cover. Remove the rocker arms and lay them in order. Remove the pushers and lay them in order. Remove the alternator belt adjusting bar and remove the belt. Remove the toothed belt protective cover and, turning the crankshaft, align the marks on the camshaft pulley and cylinder head.




Loosen the roller tensioner mounting bolts, move it to the left and tighten the bolts. Remove the toothed belt. Lock toothed pulley 2 (Fig. 2.58) of camshaft 11 with a screwdriver, loosen its mounting bolt and remove the toothed pulley. Remove thrust flange 13 and carefully remove the camshaft.

NOTE: Since May 1983, engines have been fitted with a new timing belt deflector and two-piece cover to facilitate access to the timing belt. The new cover can be installed in place of the old one. To do this, cut out the deflector with a hacksaw as shown in Fig. 2.59, without removing the cover and crankshaft pulley. Do not fit a one-piece cover to an engine with a modified deflector or one that had a two-piece cover.

Before installing the camshaft, remove the oil seal. Lubricate the journals and thrust flange with engine oil. Carefully install the camshaft in the cylinder head and install the thrust flange. Install a new oil seal using mandrel 21.094, having previously lubricated its working edge. Install the toothed belt protective cover, put it on the pulleys and tension the accessory drive belt. Lubricate and install the tappets in the appropriate seats Install the rocker arms with new mounting nuts and tighten them to a torque of 2.1-2.5 kgf·m Install the crankcase ventilation hose, throttle drive cable with bracket Lubricate the fuel pump tappet and install the tappet, gasket and fuel pump in place. Install a new gasket and distributor sensor. align the marks on its cover and on the cylinder head. Connect the high-voltage wires Install the windshield washer reservoir and connect the negative wire to the battery. Adjust the ignition timing and the carbon monoxide (CO) content in the exhaust gases at idle. Install the air filter, connect the crankcase ventilation hose and the vacuum hose.

Installing and adjusting the timing belt tension

Set the mark on the camshaft toothed pulley opposite the mark on the cylinder head (Fig. 2.60).



Turn the crankshaft and set the pulley tooth against the mark on the oil pump housing. Install the toothed belt, starting from the crankshaft pulley and continuing in a counterclockwise direction. Press the tensioner roller against the toothed belt and tighten its mounting bolts to a torque of 1.6-2.0 kgf·m. Turn the crankshaft two turns clockwise and check the alignment of the marks on the camshaft and cylinder head.

For carburetor engines Turn the crankshaft counterclockwise by approximately 60°, which corresponds to a rotation of three teeth on the camshaft pulley.

press the toothed belt with your thumb with a force of approximately 6 kgf towards the water pump. In this position, the gap "X" between the outer diameter of the water pump pulley and the belt teeth (Fig. 2.61) should be 4-6 mm. Use a drill of the appropriate diameter to measure. If necessary, move the tensioner roller.

NOTE: After installing and adjusting the timing belt tension, the crankshaft may only be rotated clockwise.

For injection engines. Tighten the timing belt by locking the crankshaft and rotating the camshaft counterclockwise using a 41 mm socket and a torque wrench with a force of 4.5-5.0 kgf. Without releasing the wrench, tighten the tensioner mounting bolts. starting with the right bolt, with a torque of 1.6-2.0 kgf·m. Make sure that the marks on the camshaft toothed pulley and cylinder head, as well as on the crankshaft pulley and oil pump housing are aligned.

Camshaft and its drive of the GLA engine

Cast iron camshaft 1 (Fig. 2.62) is mounted on three supports in the cylinder block and is driven by a single-row chain 12 from the engine crankshaft.





There are timing marks on the sprockets. The camshaft is held from axial movement by a thrust flange 6, which is attached to the cylinder block with two bolts. The chain tension is provided by a spiral spring, which presses the eccentric against the shoe 20 of the tensioner.

Removing and installing the camshaft and its drive

Since work on the camshaft is only possible after removing the engine, the procedure for removing and installing the camshaft is described in the section "Disassembling and assembling the GLA engine".







The material was copied from an information website (FORDBOOK)