Dismantling of a head of the block of cylinders is carried out in the following sequence:

– remove a head of the block of cylinders

(see subsection 3.1.6);

– turn off bolts of fastening of an inlet collector and a nut of fastening final, remove collectors;

– remove the camshaft (camshafts) and hydraulic pushers (see subsection 3.1.5);

Fig. 3.15. Compression of springs of the valve special adaptation and removal of crackers of the valve

– squeeze valve springs special adaptation and remove crackers of the valve (fig. 3.15) ;

Fig. 3.11. Head of the block of cylinders of the SOHC engine and mechanism of the drive of valves: 1 – camshaft; 2 – cover of the bearing No. 1 of the camshaft; 3 – cover of the bearing No. 2 of the camshaft; 4 – cover of the bearing No. 3 of the camshaft; 5 – cover of the bearing No. 5 of the camshaft; 6 – cogged pulley of the camshaft; 7 – bolt of fastening of a pulley of the camshaft; 8 – head of the block of cylinders; 9 – hydraulic pusher; 10 – valve crackers; 11 – plate of a valve spring; 12 – external spring of the valve; 13 – internal spring of the valve; 14 – oil scraper cap; 15 – lower plate of a valve spring; 16 – the directing valve plug; 17 – valve; 18 – cuff; 19 – cap; 20 – nut of fastening of a cover of the bearing; 21 – segment spline; And — the place of drawing alphabetic marking of the camshaft; B – the place of drawing digital marking of the camshaft

– release springs and remove the top plate 11 (see fig. 3.11 ) springs of the valve and a spring 12 and 13;

– take the valve from a head of the block of cylinders from the combustion chamber;

– remove other valves in the same way;

– remove oil scraper caps 14;

– remove the lower plates of 15 springs of valves;

– put sets of details for each valve in the separate marked packages for the subsequent their installation on the places.

Cleaning and sink of details. Before check of a condition of details execute the following operations:

– remove the remains of old laying and sealant from a head of the block of cylinders with a wooden or plastic scraper;

– clear cavities in a head of the block of cylinders a wire brush;

– clear combustion chambers of a deposit, wash out a head of the block of cylinders solvent;

– wash out and blow compressed air oil channels and channels of the cooling system of a head of the block of cylinders.

Troubleshooting of a head of the block of cylinders includes the following operations:

– check of a head of the block of cylinders on existence of chips, cracks and other damages. In the presence of cracks replace a head;

– check of a privalochny surface on existence of jags, deep scratches and other damages. If these defects cannot be eliminated with grinding of the plane, then replace a head of the block of cylinders;

Fig. 3.16. Check of planeness of a privalochny surface of a head of the block of cylinders

– check of planeness of a privalochny surface of a head of the block of cylinders by means of a testing line and the probe (fig. 3.16) . If the gap between an edge of a ruler and a surface exceeds 0,1 mm, the head needs to be replaced;

Fig. 3.17. Profile of a saddle of the inlet valve: a = 37,20 mm (engines of 1,6 l); a = 39,20 mm (engines of 1,8 l); b = 2,0 mm

Fig. 3.18. Profile of a saddle of the final valve: a = 32,40 mm; b = 2,4 mm

Fig. 3.19. Distance from a valve rod end face to the top surface of a head of the block of cylinders

– visual survey of saddles of valves. If on saddles of valves wear tracks or burnings are found, then saddles should be ground. Profiles of saddles of valves are shown in fig. 3.17 and 3.18 . After grinding of a saddle it is necessary to insert the valve, to press it against the stop to a saddle and to check distance of A (fig. 3.19) from a valve rod end face to the top surface of a head of the block of cylinders. Minimum admissible value of this distance for inlet valves of 33,8 mm, for final valves – 34,1 mm. If it is less, then the head of the block of cylinders needs to be replaced. After any processing of saddles of valves it is necessary to execute their grinding in with valves;

– measurement of values of internal diameter of the directing plugs of valves. If values exceed the most admissible size, replace guides of valves with HUNDRED.

PREVENTION After replacement of the directing plug of the valve grinding of its saddle is necessary.

Troubleshooting of details of the valvate mechanism.

Examine plates of valves. In the presence on them pointed corrosion, prozhog, cracks and wear replace valves.

If a condition of the valve satisfactory, measure diameter of a core of the valve by a micrometer in several places. At considerable divergences of values of measurements, i.e. at wear of a core, replace the valve.

Before installation of valves it is necessary to grind in them with use of pritirochny paste — mixes of small abrasive powder with engine oil. Apply paste on a saddle surface, insert the valve, install on it присос devices for inflow and rotate adaptation in both parties, periodically pressing the valve to a saddle. After the end of grinding in clear all details of dirt and the remains of paste. Check correctness of a prileganiye of the valve to a saddle — on a saddle and a plate of the valve there have to be continuous opaque corbels about 2 mm wide.

Fig. 3.20. Check of an axial deviation of springs

Examine springs of valves. In the presence of any damages they are subject to replacement. Measure values of length of springs in a free state and compare to such values of new springs. Establish springs on a flat horizontal surface and check their deviations from axes (fig. 3.20) . If at least one of springs of the valve is bent, replace both of its springs.

Examine crackers and pro-points on cores of valves for installation of crackers. In the presence of any damages replace details.

If when dismantling a head of the block of cylinders oil scraper caps were removed, they need to be replaced.

Assembly of valvate mechanisms is carried out in the following sequence:

– grease a core of the valve and the directing plug with pure engine oil, insert the valve;

– install the lower plate of valve springs;

– erase engine oil from the top part of a core of the valve;

– install the plastic plug or wrap up an adhesive tape a valve core pro-point for installation of crackers for protection from damages of working edges of an oil scraper cap at its installation;

Fig. 3.21. Installation of an oil scraper cap in an assembly mandrel: 1 – assembly mandrel; 2 – oil scraper cap

– oil fresh engine a working edge of an oil scraper cap of 2 (fig. 3.21) and establish it in an assembly mandrel 1;

– to a napressuyta against the stop an oil scraper cap for the end careful blows of the hammer to the mandrel directing valve plugs, having a mandrel strictly on an axis of the directing plug;

– remove the plastic plug or an adhesive tape from a valve core;

– establish springs of the valve and their top plate;

– squeeze valve springs special adaptation (see fig. 3.15 ) and establish crackers, propping up the valve from the combustion chamber, then slowly remove the device for compression of springs;

– collect the remained valvate mechanisms in this way;

– strike the end of the valve with the copper hammer so that it was slightly opened and all details of the valvate mechanism rose on the places.