What is a long stroke or short stroke engine? Which is better?

As laymen most of us are unaware or ignorant of the technicalities of the bike. And we would have minimal knowledge about it, as in mileage, power output, color design, fuel-efficient and price. Compared to the number of people who have sound knowledge about bikes and the riders who know very little is very low. But if one is updated with technicalities such as long stroke and short stroke, it will help him/her choose the right kind of bike according your requirement. Let us chalk out a few differences/comparisons to see which kind bike suits you.

Long stroke engine
It is understandable that using too much of technical jargon here would not help many; rather it may sound Greek and Latin. So here is a simple explanation of long stroke/short stroke engine. Basically the engine size along with the cubic capacity, which is commonly referred as 'cc' is termed as bore x stroke that are nothing but the dimensions of the cylinder. Here, 'bore' is the diameter of the cylinder and 'stroke' refers to the depth of the cylinder block. A long stroke engine also known as under-square engine therefore means that the stroke is longer as compared to the bore.



The main characteristic feature of such an engine is, because of the longer stroke the engine is capable of giving good torque at lower engine revs. Longer stroke engines help bikes that aim for higher torque at lower or relaxed engine revs. Commuter and touring bikes are classic examples of long stroke engines. A few bikes with long stroke engines that are available in India are Royal Enfield Thunderbird Twinspark, Yamaha R15 and Hero Honda Karizma. It's a mechanical edge that the long stroke has as it produces more power or torque at lower revolutions. Its also advantageous under low speed situations; such as when you needed to climb up a hill in lower speeds, the power is still generated to life the front wheel and pull the vehicle without straining.

Short stroke engine
The short stroke engine also known as over square engine bears a shorter bore when compared to the dimension of the stroke. The modern-day engines that tend to be faster-rotating are all short-stroke one (stroke-to-bore ratio less than or equal to one) makes that makes the engines quite compact and their max torque reached at higher revs. The short-stroked engine needs to spin faster to move same amount of air, however it's capable of spinning faster. For obvious reasons the engine will exhaust the oil faster here

Bikes that aim to fulfil the requirement of fast building of power such an engine is ideal, as the short stroke enables faster engine revs. The short stroke engine is perfect for racing bikes and super sports bikes. Apache RTR 160 and Pulsar 150 are the two bikes with short stroke engine that are available in the Indian market.

The ideal type of engine largely depends on individual taste/requirement, if the rider is wants to race away on the roads then short stroke engine enabled bike suits the best and if you want the bike to have a great pulling ability as in to carry heavy loads or a heavy pillion then long stroke engine will fit your bill.