Engines : Long Stroke | Short Stroke

My two cents on the long and short of this stroke business.

An engine stroke basically refers to the full travel length of the piston in one direction along the cylinder walls of an internal combustion engine.

Longer Stroke :

evb-my_hog

V Twin – Long Stroke Engine

A long stroke engine means pistons travel more hence giving out a punchier, longer torquing push to the flywheel, this long travel torquing push also means that you hit the rpm threshold early after which the engine delivers little extra torque due to mechanical energy loss. If you’re the type that loves the low rpm thump and grunt of the engine while it effortlessly pulls you away even at a higher gear, then long strokes are your thing.

For : The cruising types, easy riding like a king gliding o’er the landscape of mere minions and the rest.

Shorter Stroke :

2012-yamaha-r1-5

Inline 4 – Short Stroke Engine

A short stroke means piston travels lesser, which in turn means that it can be run at a higher revolution per minute rate. Moving parts are minimized providing the ability to draw more power through the bandwidth of an increased rpm threshold. However, this means that relatively low torque is delivered at low rpms and the engine needs to be juiced up to a higher rpm in order to harness the torque it delivers.

For: The racy types that don’t mind changing gears constantly or revving up high, the type that love making her scream with pleasure.

Analogy : fig0224

In car terms, you can imagine the short stroke as a high revving petrol engine while long strokes have a low rpm torquey characteristic like a naturally aspirated diesel engine.

or

Heavy lugging vehicles have long stroke engines vs motorboat engines that have a very short stroke.

To sum up :

It becomes a matter of personal choice eventually as to which kind of engine you would prefer to say as ‘better’ than the others but knowing your stroke preferences can translate into making a much more informed choice when buying a motorcycle.

The RPM gauge red-line is a big indicator in modern bikes to gauge the stroke of an engine, short strokes can go up to almost 18000 engine rpm whereas very long strokes have a red-line placed as low as 5600 engine rpm.

  • Long Strokes = More usable lugging torque at low to cruising rpm range with lesser gear shifts while riding.
  • Short Stroke = Progressive spread out torque that peaks at high rpm and needs relatively more gear changes while street riding.

Medium Stroke engines haven’t been mentioned due to the nature of this post being a comparison, so i’ll keep that for the next post.

Ride on ya travelling band of precious loonies, cheers and ride safe as well.

 

 

 

 

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