A compression piston top and bottom plane of the cylinder cover only 1mm clearance. Reasons for piston cylinder head with top touch:
(1) in the maintenance or assembly, will not be a small screw, nut or screw into the intake pipe or the piston (such as disassembly of injectors, from the hole into, or inhalation of air suction), or small pads glued below the cylinder head, cylinder head installation didn’t notice when left behind the combustion chamber, the abnormal sound occurs start the car, so that the piston and cylinder head collision.
(2) Baotou beiben heavy truck fittings for connecting rod damage may cause the piston to touch the cylinder head. This collision is inertial collision, is not caused by the piston rod or too long, so in the drive of the flywheel, not touch piston cylinder head, only when the engine is running (and hear the sound increases with increased speed, low noise and light). But at this time often connecting rod tile serious, this kind of inertia collision sound has been tile noise cover.
(3) in Baotou beiben heavy truck parts connecting tiles, tiles will be fitted or misloading other connecting rod cap. Although the screws tightened, but tile or oval (connecting rod body and cover pair processing, not change inertia), causing the piston impact cylinder head, light, crisp sound blah sound, after ringing off the oil, does not diminish, large cylinder head vibration. Therefore, special attention should be paid to this point during maintenance.
(4) Baotou beiben heavy truck parts connecting rod bolts loose, also caused by the inertia top touching the cylinder cover, should be selected according to the requirements of a qualified bolt, prohibit the use of the old bolt.