What is over square ratio in IC engine?

An engine is described as over-square or short-stroke if its cylinders have a greater bore diameter than its stroke length, giving a bore/stroke ratio greater than 1.04.

What is over square engine?

Oversquare or short-stroke engine An engine is described as oversquare or short-stroke if its cylinders have a greater bore diameter than its stroke length, giving a bore/stroke ratio greater than 1:1.

What is the advantage of increased stroke bore ratio?

Larger bore-to-stroke ratios allow increased valve sizes and improved breathing, especially at higher engine speeds. Larger bore-to-stroke ratios result in lower piston speeds at any given engine speed, thus allowing higher engine speeds.

Which IC engine has higher compression ratio?

The compression ratio may be higher in engines running exclusively on liquefied petroleum gas (LPG or “propane autogas”) or compressed natural gas, due to the higher octane rating of these fuels. Kerosene engines typically use a compression ratio of 6.5 or lower.

What does bored and stroked mean?

Bore: Cylinder bore is the measurement of the diameter of the cylinders in an engine. Stroke: Stroke is the amount of movement a piston can move up and down. A bored engine happens when you machine out the block. A stroked engine is simple to build.

Which is better short stroke or Longstroke?

For any given cubic capacity, an over square engine has to move lesser as it has a wider bore. These engines also have lesser inertial stress which allows them to be equipped with faster valve timing. This lends a short stroke engine, in general, the ability to rev higher than its long stroke counterparts.

What is over square ratio?

An engine is called an ‘Over-square’ engine when its cylinder bore is wider than its stroke. Hence, this design tends to produce higher engine speed and is typically used in high-speed cars & bikes. ‘Over-Square’ engine has the bore-stroke ratio greater than 1:1.

What is under Square and over square engine?

If the piston stroke length is larger than the bore diameter, the engine is called an undersquare engine. And if the bore diameter is larger than the stroke length, the engine is called an oversquare engine. If both the stroke and the bore are of same length, then it is called a square engine.

Does increasing stroke increase torque?

As the stroke increases, the torque output of the engine will increase due to the additional leverage created by the ‘distance’ that the force is acting from. Power is related to the torque output at a specific engine speed so an increase in horsepower will be had with an increase in stroke.

Does a bigger piston mean more power?

The short answer is that a bigger bore is generally the best way to get more power. It creates more space, allowing for bigger valve openings, which in turn can bring more fuel and air into the cylinder. A bigger bore with a shorter stroke also allows an engine to rev higher, which creates more horsepower.

Why is higher compression ratio better?

A higher compression ratio (CR) is beneficial for engines. That’s because the higher ratio allows for an engine to extract more energy from the combustion process due to better thermal efficiency. Higher compression ratios allow the same combustion temperatures to be achieved with less fuel.

What is compression ratio in IC engines?

The compression ratio is defined as the ratio between the volume of the cylinder with the piston in the bottom position, Vbottom (largest volume), and in the top position, Vtop (smallest volume). The higher this ratio, the greater will be the power output from a given engine. It is generally in the 6–10 range.

What is bore-stroke ratio and square engine design?

For e.g. an engine with the bore diameter of 83mm and stroke-length of 67mm which forms an ‘over square design’. Therefore, the ‘Bore -stroke ratio’ = 1.23 : 1. Advantages of ‘Over-Square’ Design: Less frictional losses & load on bearings. Higher engine speeds. Reduces engine height thereby lowering the bonnet line.

Which is the correct definition of an oversquare engine?

Oversquare or short-stroke engine. An engine is described as oversquare or short-stroke if its cylinders have a greater bore diameter than its stroke length, giving a bore/stroke ratio greater than 1:1.

What is the stroke ratio of a reciprocating engine?

In a reciprocating piston engine, the stroke ratio, defined by either bore/stroke ratio or stroke/bore ratio, is a term to describe the ratio between cylinder bore diameter and piston stroke.

Which is better a square or over square engine?

A square engine will generally produce more torque than the same cubic inch over-square design; however the rpm will be lower so the maximum horsepower produced will also generally be lower. Also we find that in a square design the spread between peak torque and peak horsepower will be closer together than in the over-square design.