What is bumping clearance? What happens if bumping clearance too much or too little.

 ✍️What is bumping clearance? What happens if bumping clearance too

much or too little.

1) Bumping clearance is to accommodate thermal expansion and to avoid

piston hitting the cylinder cover head.

2) A clearance is given between piston head and cylinder head at piston TDC

3) Bumping clearance should be as small possible, high clearance reduce

volumetric efficiency

4) Low clearance will result in mechanical fault

5) Bumping clearance to be checked and measured every major overhaul

6) Bumping clearance normally 6% of swept volume

7) Bumping clearance affect by thickness of gasket and bearing wear,