Problems Related To Piston Rings - Multiple Choice Questions and Answer

Problems Related To Piston Rings - Multiple Choice Questions and Answer Points : problems related to piston rings, ic, engine, problems in internal combustion engine, auto diesel, mcqs, evaluation, objective type question and answer, multiple choice questions and answer 1. What are the two purposes of keeping clearance
a) For lubricating film
b) Allow for expansion of piston due to heat

2. Ring gap is the ___________ between the ends of the rings.
a) Space
b) Clearance
c) Allowance
d) Fit

Piston Ring Problems

Piston Ring Problems Points : Piston Ring Problems, problems in internal combustion engines, ic, engine a) Blow-by oiling-up troubles due to worn rings and undersize rings.
b) Wear and clearance due to tight rings.
c) Breakage of rings due to ridge formation at the top of the cylinder.
d) Breakage of rings during fitting due to haphazard methods of expanding the rings with fingers and not using the ring-fitting too.
e) Breaking of rings due to not fitting the rings the correct way’ up.

Blow-By

Blow-By Points : blow-by, problems in internal combustion engines, ic, engine Excessive “blow-by” combustion gases are allowed to escape past the piston rings on the power stroke, creating excessive crankcase pressure build up which in turn forces gases, oil vapors and oil through the breather system to be burned in the combustion chamber via the induction system. This excessive crankcase pressure will also actually force oil and oil vapors past the oil control and compression rings on the induction stroke especially under high manifold compression conditions.

Cylinder Bore & Piston Rings

Cylinder Bore & Piston Rings Points : cylinder bore & piston rings, problems in internal combustion engines, ic, engine We can divide this subject into two specific problems first-Oil Migration (combustion chamber). Excessive oil film thickness deposited on the cylinder wall will allow the piston rings to hydroplane on this oil film, which allows oil to migrate into the combustion chamber to be burned and can he caused by one or more of the following:

• Oil pan overfill
• Wrong cylinder/bore cross hatch honing method (too flat causing oil “piddling”).
• Inadequate piston oil control ring wiping, due to low tension and probably due to excessive oil rail and gaps.

Expansion, Blow-By, Rapid Wear and Clearance

Expansion, Blow-By, Rapid Wear and Clearance Points : expansion, blow-by, rapid wear and clearance, problems in internal combustion engines, ic, engine Automotive pistons normally use three rings two compression rings and one oil ring. It is important to understand how variation in ring construction provides different operating characteristics. Ringside, back and gap clearances are very important. They must be within factory specification or poor engine performance could result.

The faces of the piston rings can be coated with chrome or other metals. Soft ring coating of porous metal (usually iron) help the ring wear in quickly, forming a good seal. The soft outer surface will wear away rapidly the ring confirms to the shape of the cylinder. Also called quick sealing rings, they are commonly recommended for USED CYLINDERS that are slightly worn Hard ring coatings, such as chrome are used to increase ring life and reduce friction.

Scuffing, Sticking, Breaking of Piston Rings

Scuffing, Sticking, Breaking of Piston Rings Points : Scuffing, Sticking, Breaking of Piston Rings, problems in internal combustion engines, ic, engine The principal requirement of a piston ring is that when compressed the fuel into the cylinder, it shall bear evenly all round, and shall not have too large a gap.

In order to prevent the escape of gases past the rings it is necessary to arrange for the latte to exert a certain radial pressure outwards against the cylinder walls. This pressure must only be sufficient for the purpose during the normal working conditions for excessive pressures reduce engine power and also give rise to greater cylinder wear. Modern piston rings are of the narrow axial thickness type, of good quality alloy cast iron having elasticity properties, or flexibility so that they can readily be sprung over the piston without breakage or permanent set.

Problems Related To Piston Rings

Problems Related To Piston Rings Points : problems related to piston rings, problems in internal combustion engines, ic, engine Piston rings seal the clearance between the outside of the piston and the cylinder wall. They must keep combustion pressure from entering the crankcase. They must also keep oil from entering the combustion chambers. The principal requirement of a piston ring is that when compressed into the cylinder it shall bear evenly a] round, and shall not have too large a gap.